Animal The Definitive Visual Guide

ELAPIDS 399

Elapids

PHYLUM Chordata Although elapids account for less than Venom venom canal. The elapids include
CLASS Reptilia one in 10 of the world’s snakes, all of them some of the world’s most dangerous
ORDER Squamata are venomous—many dangerously The venom of elapids varies in its snakes, such as the taipan. Others,
so. They include cobras, coral potency and the organs and body however, are inoffensive and too small
SUBORDER Serpentes snakes, mambas, kraits, and systems that it affects. Most elapids, to endanger humans.
including cobras, release venom that
SUPERFAMILY Caenophidia sea snakes, and are found mainly acts on the nervous system, paralyzing Reproduction
muscles used in respiration. In some
FAMILY Elapidae in the tropics and in the Southern Most elapids lay eggs but a few are
elapids, the venom runs down bearers of live young. Sea snakes,
SPECIES 361 Hemisphere. There are ground grooves in the fangs, while for instance, give birth in the water,
in others, the fangs whereas sea kraits come ashore to
dwelling and semiburrowing species of contain an internal lay eggs. A number of Asiatic cobras
build nests out of dead leaves and
elapids, as well as some that live and hunt in trees. Some are other forest debris. Females guard the
eggs fiercely, protecting them from
fast-moving, diurnal hunters, while others are more secretive, potential predators.

hunting under the cover of darkness. Sea snakes and sea kraits

are wholly marine. Elapids are related to colubrids (see pp.393–8)

and look superficially similar, but they differ from most of them

in having fangs located towards the front of the upper jaw. This

allows them to inject venom in a sudden and deadly strike.

Anatomy markings that warn would-be SPITTING COBRA
predators to leave them alone. Some
Elapids typically have a slender, cobras intimidate their enemies by Some cobras (including the
roughly cylindrical body, with smooth, raising the front part of their bodies Mozambique spitting cobra shown
shiny scales. Sea snakes—sometimes off the ground, and expanding their here), can spray their victims with
classified in a family of their own—are ribs to form a hood. venom by forcing it out at high speed
noticeably different, with a flattened through apertures in the fangs. Once
tail for swimming. Most terrestrial sprayed into the victim’s eyes, it
elapids have camouflage colors and causes great pain and temporary, or
markings, but coral snakes have bold sometimes even permanent, blindness.

REPTILES

Acanthophis praelongus from light gray to gray-brown or LIVING LURE Austrelaps superbus
almost black, with paler rings or bands.
Northern death Northern death adders feed mainly on The tip of the northern death Australian
adder small mammals, lizards, and birds, and adder’s tail is very slender, and copperhead
they use their thin, wormlike tails to lure is considerably paler than the rest
Length 12 – 39 in animals within striking range. They give of the body. When hunting, the Length 41⁄4 – 51⁄2 ft
(30 – 100 cm) birth to live young, producing litters of snake lies still, and wriggles the tail (1.3 – 1.7 m)
Breeding Viviparous up to 8 each time they breed. A very tip to lure prey close enough to Breeding Viviparous
Habit Terrestrial similar species, the southern death strike. Rapid-acting venom kills Habit Terrestrial
Status Not evaluated adder (Acanthophis antarcticus), is the victim, which the snake can Status Not evaluated
widespread in eastern and southern
Location New Guinea, Australia, and is sometimes found then swallow at leisure. Location S.E. Australia,
N. Australia close to urban areas. Like its northern N. Tasmania
counterpart, it has a bite that is
potentially fatal to humans.

Despite its name, wedge-shaped white rings This inhabitant of marshes and swamps
this snake is not head around body is active both during the day and at
a true adder (see night, and feeds mainly on frogs. It is
pp.402 – 3), but thick body gray or reddish brown to black above,
an unusually and cream or yellow on the flanks.
stout-bodied elapid. Although it hibernates in winter, it can
It is one of Australia’s most tolerate low temperatures and is active
venomous snakes, hunting longer than other reptiles.
by a sit-and-wait
strategy, and striking at ADDER LOOK-ALIKE
the least provocation. A thick body, wedge-shaped
It is normally active at head, and narrow neck are all
night; during the day, it features normally seen in true
relies on its camouflage adders and vipers, rather than in
markings to avoid being elapids. The northern death adder
seen. Adults vary in color also has raised “horns” over its eyes.

400 SNAKES

Dendroaspis angusticeps Dendroaspis polylepis FIGHTING FOR A MATE

East African green Black mamba During the breeding season, male black
mamba mambas fight by raising and intertwining
Length 81⁄4 – 11 ft the front half of their bodies, with each
Length 5 – 81⁄4 ft (2.5 – 3.5 m) snake trying to force its opponent to the
(1.5 – 2.5 m) Breeding Oviparous ground. However, the fight is ritualized
Breeding Oviparous Habit Terrestrial and does not involve any serious harm.
Habit Arboreal Status Least concern Following this test of strength, the
Status Not evaluated
Location E. and S.E. Africa Location E. and southern winner mates with any females
Africa in his territory.

The bright green color, slender shape, In addition to being one of the most
and long tail of the East African green poisonous snakes, the black mamba
mamba are all features that are ideally is probably the fastest, making it one
suited to an animal living in trees. Alert of the world’s most dangerous predators.
and fast moving, this snake chases In short bursts, it can reach 121⁄2 mph
its prey through the canopy and, if (20 kph), which is fast enough to overtake
disturbed, it usually moves swiftly someone moving at a brisk run. The
to higher branches or passes from black mamba is not actually black, but
the branches of one tree to another; gray or brown, with a streamlined body
if cornered, it will turn and strike. covered with large, smooth scales.
Although highly venomous, Highly territorial, it makes its home den in
this mamba rarely comes a rock crevice or a hollow tree. It is active
into conflict with humans. during the day, and feeds on birds and
small mammals. Females lay 12 – 17 eggs
smooth in chambers underground. The venom of
scales the black mamba is very fast-acting, and
bites are often fatal if not treated quickly.
narrow
head OCCASIONAL CLIMBER
This primarily ground-living snake, mostly found
REPTILES in open woodland, may also occasionally climb.
Despite its size, it is highly agile, effortlessly
sliding through thorn bushes and trees.

Laticauda colubrina paddle-shaped tails and live and feed Naja naja their potent neurotoxic venom. The
at sea. It is found in coastal waters, principal predators of Indian cobras,
Yellow-lipped mangrove swamps, and coral reefs, Indian cobra other than humans, are carnivorous
sea krait where it hunts fishes—particularly eels. mammals—notably mongooses—
Like all sea snakes, it is highly poisonous, Length 4 – 51⁄2 ft and birds of prey.
Length 31⁄4 – 61⁄2 ft but poses no threat to humans since it (1.2 – 1.7 m)
(1 – 2 m) does not bite. Most sea snakes spend Breeding Oviparous expanded
Breeding Oviparous their entire lives at sea, and give birth Habit Terrestrial hood
Habit Aquatic to live young, but the yellow-lipped sea Status Not evaluated
Status Least concern krait and its relatives come ashore to
lay their eggs under leaf litter. Location S. Asia

Location S. and S.E. Asia

broad black Renowned for its use in snake
bands charming, this animal is one of the
most dangerous snakes in India.
The bluish gray, yellow-lipped sea It is responsible for a relatively small
krait is one of about 40 species but nonetheless significant proportion
of snakes that have flattened, of snake-bite mortalities, which total
50,000 per year in India alone. This
Micrurus lemniscatus Each species has a characteristic is partly due to its preference for rice broad
pattern of contrasting bands, warning paddies and roadside banks, which ventral
South American predators that they are poisonous. are often close to villages and so bring scales
coral snake However, because coral snakes have it into contact with humans. Indian
a semiburrowing lifestyle, generally cobras are very variable in color,
Length 231⁄2 – 35 in emerging only at night, their colors are ranging from brown to black, but
(60 – 90 cm) often concealed. Coral snakes feed on most individuals have distinctive, pale
Breeding Oviparous small lizards and snakes. They have “spectacle” markings on the back of the
Habit Semiburrowing highly toxic venom, but hood. As with other cobras, the hood is
Status Least concern human fatalities are rare. spread out when the snake feels

Location N. and C. South threatened, but is folded away at
America other times. Although Indian
cobras are sometimes seen
This brilliantly colored reptile is one of sequenced smooth basking in the sun, they are
about 40 species of coral snakes that color bands scales most active at night, and are
occur in warm parts of the Americas. good climbers and swimmers.
small head They feed on small mammals,
birds, lizards, and other snakes,
killing them within seconds with

ELAPIDS 401

Naja pallida Naja haje other snakes, small mammals, toads, Calliophis bivirgata
and birds, including domestic poultry,
Red spitting cobra Egyptian cobra killing prey with its fast-acting venom; Blue coral snake
it also feeds on eggs. Individuals are
Length 28 – 47 in Length 31⁄4 – 73⁄4 ft territorial and frequently fight one Length 4 – 41⁄2 ft
(70 – 120 cm) (1 – 2.4 m), another. Females lay 8 – 20 eggs, often in (1.2 – 1.4 m)
Breeding Oviparous max 81⁄4 ft (2.5 m) termite mounds, and the eggs hatch after Breeding Oviparous
Habit Terrestrial Breeding Oviparous an incubation period of about 60 days. Habit Terrestrial
Status Not evaluated Habit Terrestrial Status Least concern
Status Not evaluated large eyes
Location N. and E. Africa Location N., W., and Location S.E. Asia
E. Africa

This African snake is one of several Usually brown or grayish, sometimes mouth open large
cobras that have evolved a unique way with black bands, the Egyptian cobra wide to head
of defending themselves. If threatened, may grow up to 81⁄4 ft (2.5 m) long. An intimidate
they can squirt venom out of small inhabitant of desert, grassland, and
apertures in their fangs, spraying a cloud urban areas, it is also found in fields near hood spreads Bright orange markings on the underside,
of droplets 61⁄2 ft (2 m) at their enemy. oases and wadis, and tends to avoid in defense head, and tail of the blue coral snake act
Sprayed venom does not kill, but it can dense forest and the most arid deserts. thickset body as a warning device to keep potential
cause permanent blindness. The red This cobra is primarily nocturnal, but predators at bay. A highly venomous
spitting cobra varies in color from red to can sometimes be seen basking in the front-fanged species, its poison glands
gray, and is active at night and early in sun early in the morning. Quick to rear extend along almost one-third of its entire
the morning. Females lay up to 15 eggs and spread its broad, rounded hood body length. It is also known as the
in a burrow or in rotting vegetation. to intimidate an opponent, this highly “100-pace snake,” referring to the
venomous cobra will hiss and advance distance a human is thought capable
black band narrow on its aggressor if the latter is
across throat hood undeterred, and may of traveling before succumbing to
eventually strike, the venom. However, it is generally
delivering a inoffensive, only killing other REPTILES
bite that is fatal snakes for food. Only a few cases
for humans if an of human fatalities have ever
antivenom is not been recorded.
administered
promptly. It
actively pursues

Notechis scutatus Ophiophagus hannah although it rarely attempts to bite. In fact, Oxyuranus scutellatus
few cases of king cobra bites on humans
Australian tiger King cobra have been recorded, because this Coastal taipan
snake retiring snake shuns human contact,
Length 93⁄4 – 16 ft living mainly in deep forest. Slender Length 61⁄2 – 12 ft
Length 31⁄4 – 7 ft (3 – 5 m) and smooth-scaled, the king cobra is (2 – 3.6 m)
(1 – 2.1 m) Breeding Oviparous a good swimmer and is often found Breeding Oviparous
Breeding Viviparous Habit Terrestrial near water. Adults are plain brown, Habit Terrestrial
Habit Terrestrial Status Vulnerable while juveniles are darker and marked Status Not evaluated
Status Least concern with pale chevrons down their backs.
Location S. and S.E. Asia Unusually for a snake, this species Location S. New Guinea,
is at least temporarily monogamous, N. Australia
pairs apparently remaining together
Location S.E. Australia during the breeding season. Females
lay 21 – 40 eggs, mostly in piles of dead
large The king cobra, or hamadryad, is the vegetation, which are guarded by both Although nondescript in appearance, the
scales longest venomous snake and a parents until they hatch. The king cobra plain tan or dark brown coastal taipan
specialized hunter of other snakes. It may live for more than is Australia’s most venomous snake.
This extremely venomous species is 20 years in captivity. It is shy and seldom seen, but when
responsible for many potentially fatal sometimes reaches a length of encountered, is capable of striking
snake bites in Australia. It may be gray, more than 16 ft (5 m), which narrow
brown, dark brown, or olive-brown, allows it to overpower and kill hood with deadly speed. It feeds mainly
often with narrow, light yellow bands. other snakes of a considerable on mammals, but also on birds and
Although active mainly during the day, size. When threatened, it raises lizards, sometimes entering burrows
the Australian tiger snake may also be to trap its prey underground. Females
active early in the morning and in the the front third of its body so that it lay 3 – 20 eggs each time they breed.
evening, and on warm nights; it remains stands 5 ft (1.5 m) tall, erects a narrow Taipan bites can be fatal to humans,
hidden in spells of cold weather. Its hood, and may strike downward, but an effective antivenom means that
prey consists mainly of frogs, which it
chases then subdues with its venom. In long body fatalities are now relatively rare.
defense, it flattens its neck and rears its
body slightly off the ground. Females smooth
give birth to about 30 live young. scales

keeled
scales

402 SNAKES

Vipers

PHYLUM Chordata Vipers are the most highly evolved of all Anatomy their heat-sensitive pits, they can
CLASS Reptilia snakes. They have long, hinged fangs, and not only detect the presence of prey
ORDER Squamata some (the pit vipers) also have a pair of Most vipers are short and stocky but also gauge its distance and the
heat-sensitive pits between their eyes and with wide, triangular heads and direction in which it lies. Rattlesnakes,
SUBORDER Serpentes nostrils. Vipers are found in a wide range of rough, keeled scales. The head has which are a type of pit viper, have a
long fangs, which are folded against unique warning device in the form of
SUPERFAMILY Caenophidia climates, and compared to other snakes are the roof of the mouth when not in use, a rattle at the end of the tail.
and large venom glands. Vipers are
FAMILY Viperidae better equipped to deal with cold conditions. generally sluggish snakes and rely on Venom
camouflage to go undetected: they
SPECIES 337 Many live at high elevations or Most vipers ambush their prey,
are often colored to blend in some using the brightly colored
in desert areas with cold with the surface on which they tip of their tail as a lure. They lunge
live and may have intricate open-mouthed and stab the victim
winters. Some are even found north of the geometric markings to using their long fangs, penetrating fur
break up their outline. and feathers, to reach the vital organs.
Arctic Circle. Vipers live on the ground or Heat detection is more The venom varies from species to
advanced in pit vipers species, but often contains proteins
in trees. Some species use rodent than in any other that break down blood cells and
snakes. Using cause internal hemorrhaging. The
burrows as temporary shelters. venom being relatively slow acting,
vipers deliver large amounts of it,
STRIKING POSITION unlike cobras. For the prey, death
may not be instantaneous.
When preparing to strike, the desert
horned viper (shown here) opens its Reproduction
mouth and moves its fangs down from
their usual position flat against the Although some vipers lay eggs, most
roof of the mouth. The jaws are give birth to live young. Females retain
opened wide so that the the developing eggs in their body and
fangs point forward bask during the day to accelerate the
towards the prey.
embryos’ development. Many
REPTILES species breed only every 2,
or even 3 years, using the
nonbreeding years to feed
and recover their body weight.

Atheris mabuensis Bitis arietans DEFENSIVE BEHAVIOR Bitis caudalis

Mount Mabu Puff adder Highly venomous, the puff adder Horned adder
forest viper is ferocious when disturbed, and
Location Africa (south Length 31⁄4 ft (1 m), defends itself by inflating its body Length 12 – 20 in
Length 15 in of Sahara and Morocco), max 61⁄4 ft (1.9 m) and making a long, low hissing (30 – 50 cm)
(38 cm) max Saudi Arabia Breeding Viviparous sound. If further provoked, it may Breeding Viviparous
Breeding Viviparous Habit Terrestrial strike, delivering a fatal bite. Habit Terrestrial
Habit Terrestrial Status Not evaluated Status Not evaluated
Status Not evaluated like a caterpillar. The puff adder hunts
in the evening and at night for small Location Southern Africa
mammals and, occasionally, birds and
Location E. Africa
reptiles. It ambushes prey
This is the mostly southerly—and The puff adder is a thick-bodied snake and strikes quickly, The horned adder is gray, brown,
smallest—of Atheris African forest with a wide, flattened head and a injecting large amounts reddish, or orange, with a single horn
vipers; it was described as a new rounded snout. The male is smaller of venom. Males combat and over each eye. Its flattened body and
species in 2009 and is known only and often more brightly colored than follow the trails of females in the spring. rough scales help it shuffle down into
from the midaltitude rain forest of Mount the female. Sluggish and slow moving, This adder’s litter size may reach 154 loose sand in order to escape the heat
Mabu and Mount Namuli in northern larger individuals crawl in a straight line, in exceptional cases, the largest of any and to hide. When crossing loose sand,
Mozambique. Its highly restricted snake, but is more typically 20–40. it may move in a sideways looping
distribution makes it at risk from habitat dark-edged, The puff adder is highly dangerous to motion, known as sidewinding. It hunts
destruction. Adults resemble the white chevrons humans, and is responsible for most mainly in the evening—prey may be
juveniles of larger allied species and, of the lethal snake bites in Africa. attracted to its twitching tail.
unlike most members of its genus,
are ground dwelling. It may be a broad head
specialized hunter—taking small frogs
and geckos among leaf litter.

BODY MARKINGS dark
The puff adder markings
has a yellowish
brown or gray body wide head
with white chevrons
along its back. Some
individuals may also
have yellow markings.

VIPERS 403

Bitis gabonica excellent camouflage, making it Cerastes cerastes protected from the heat. Active at night,
extremely difficult to detect. A sluggish, it lies in ambush for rodents, lizards,
Gaboon viper usually placid snake, it generally lies Desert horned viper and birds, sometimes partially buried,
motionless on the forest floor, moving then launches a rapid strike. When
Length 4 ft (1.2 m), only when prey—namely rodents and Length 12 – 231⁄2 in threatened, it forms a coil, rubbing
max 61⁄2 ft (2 m) larger mammals, birds, and frogs— (30 – 60 cm) together the scales on its flanks to
Breeding Viviparous comes within striking range. Large, Breeding Oviparous create a rasping sound.
Habit Terrestrial heavy-bodied individuals normally crawl Habit Terrestrial dusty color provides camouflage
Status Not evaluated in a straight line, like a caterpillar. When Status Not evaluated
disturbed, this viper gives a loud, low dark-edged brown blotches down its
Location W. and C. Africa hiss and may bite, but only as a last Location N. Africa back. A sit-and-wait predator, it relies
resort; the bite is often fatal to humans on its camouflage to escape detection
The immense, thickset body, massive, if not treated at once. Males combat Also known as the Sahara horned by unwary prey, then strikes. In defense,
triangular head with small eyes, and during the breeding season, and viper, this short, squat snake usually it forms a tight coil, hisses, and strikes
patterning of interlocking, geometric females give birth to 16 – 60 young has a thornlike horn over each eye. hard, often lifting its body off the ground
shapes along the back, make the every 2 – 3 years. The strongly keeled scales on its body in the process.
gaboon viper instantly help the snake shuffle down into the stout body
recognizable. When seen geometric sand, where it remains hidden and with distinctive
away from its natural patterning markings
habitat, it appears to be
colorful and conspicuous, Daboia russelli
with its distinct markings in
pale purple, tan, cream, and Russell’s viper
brown. However, in
the wild, its coloration Length 31⁄4 ft (1 m),
and patterning provide max 5 ft (1.5 m)
Breeding Viviparous
Habit Terrestrial
Status Not evaluated

venom glands Location S. and S.E. Asia
behind eyes

Echis pyramidum rubbed together. When threatened, Although this is a sluggish animal that REPTILES
saw-scaled vipers use this sound as usually remains coiled and well hidden
Northeast African a warning signal, in much the same way during the day, Russell’s viper is one of
saw-scaled viper as rattlesnakes (see p.404) use their tails. the most dangerous snakes to humans
Like its relatives, the northeast African in southern Asia. It is distinguished by
Length 12 – 231⁄2 in saw-scaled viper hunts small mammals, its light brown body with 3 rows of oval,
(30 – 60 cm) amphibians, reptiles, and invertebrates
Breeding Oviparous Vipera berus mate, with males engaging in protracted
Habit Terrestrial at night. Females combat for the chance to pair up with
Status Least concern lay clutches of Common adder females. Females breed only about once
Location N. and N.E. Africa 6 – 20 eggs. every 2 or 3 years, producing litters of up
to 20 young that may have been fathered
Despite its small size, this quick-moving Length 26 – 35 in by several different males. Adders are
snake is highly dangerous, with venom (65 – 90 cm) only mildly venomous. In humans, their
potent enough to kill humans. It belongs Breeding Viviparous bite can cause swelling and pain, but
to a small genus of vipers (known as Habit Semiterrestrial is rarely fatal.
saw-scaled or carpet vipers) that have Status Least concern
strongly keeled scales that produce
a loud rasping sound when they are Location Europe, C. to
E. Asia

stout body pear-shaped flat head
horn on snout head
thick
Vipera ammodytes The common adder—or common body
viper—is the only venomous snake in zigzag line
Nose-horned viper northwest Europe, and is the most down back
widely distributed snake in the viper
Length 26 – 35 in unknown. It is usually slow-moving, family. It lives in a wide range of habitats,
(65 – 90 cm) unless provoked, and often coils quietly including rocky slopes 9,900 ft (3,000 m)
Breeding Viviparous among rocks on hillsides. Mainly diurnal, high in the European Alps, and open
Habit Terrestrial it may become nocturnal in midsummer tundra north of the Arctic Circle. Its color
Status Least concern in certain parts of its range. varies from gray, brown, or rust to
completely black, but most individuals
Location S.E. Europe, zigzag line have a distinctive, zigzag line running
W. Asia down back down their back. Common adders may
occasionally reach as much as 35 in
The light brown, reddish brown, or gray (90 cm) long. They feed primarily on small
nose-horned viper is Europe’s most rodents and lizards, either ambushing or
dangerous snake, although its bite
is rarely fatal if treated. It has a actively pursuing them, but they also
short, fleshy horn on its snout, spend much of their time basking in
the function of which is as yet the sun. In the north of their range,
where winters are colder—for
example, in Scandinavia—they
hibernate for up to 8 months each

year. In spring, the snakes emerge to

404 SNAKES

Crotalus atrox composed of loosely connected
segments, which are added to after
Western diamondback each shedding. Used to warn and
rattlesnake deter intruders, the rattle consists
of up to 16 segments in adults.
Length Up to 61⁄2 ft Newborns, measuring about 12 in
(2 m) (30 cm), do not possess a rattle,
Breeding Viviparous but instead have a small “button”
Habit Terrestrial that develops with sloughing.
Status Least concern However, they are already
equipped with needle-sharp
Location S. USA, fangs and extremely toxic
N. Mexico venom. It takes between 3
to 4 years for them to reach
sexual maturity.

This large, heavy-bodied snake is North FATAL STRIKE
America’s most dangerous rattlesnake, The western diamondback
with the highest rate of human fatalities. rattlesnake usually hunts by
A highly venomous and effective hunter, ambushing its victim, then
the western diamondback rattlesnake striking with its long fangs.
feeds mainly on small mammals, birds, Its lethal venom contains
and lizards, but can be deadly to larger
animals or humans, if provoked. The a mixture of toxins that
rattle, its most distinctive feature, is can kill victims in seconds.
a horny section at the end of the tail The snake waits for its prey

to die before eating.

broad diamond
shapes

forked
tongue

REPTILES

HEAVY-BODIED SNAKE segmented
This bulky snake varies in color according to its rattle
location and habitat, and may be gray, brown, olive-
green, or reddish brown. The tail is marked with
black and white bands just in front of the rattle.

ATTACK AND DEFENSE

The western diamondback rattlesnake heat
is a well-armed and deadly predator that pits
has developed effective methods for fanged
hunting prey. However, the solitary snake mouth
will often withdraw from confrontation if
disturbed, using its rattle to deter intruders.

buzzing
rattle

STALKING PREY DEATH RATTLE
The western diamondback rattlesnake The rattlesnake sounds its
uses the pair of heat-sensitive pits unmistakable rattle as a means
between its eyes and nostrils to detect of defense and an ominous
and locate warm-blooded prey. warning not to approach.
EATING ITS PREY
Having stunned a rodent victim
with its venomous bite, the
rattlesnake waits for it to die
before swallowing it whole.

405 REPTILES

406 SNAKES

Agkistrodon contortrix lizards, and invertebrates, using the Bothrops atrox Calloselasma rhodostoma
heat-sensitive pits between its eyes and
Copperhead nostrils to locate prey in total darkness. Common lancehead Malaysian pit viper
Its bite is venomous, but rarely serious
Length 231⁄2 – 51 in Length 31⁄4 ft (1m), Length 28 – 39 in
(60 – 130 cm) for humans. The female gives birth max 5 ft (1.5 m) (70 – 100 cm)
Breeding Viviparous to 1 – 15 young every other year. Breeding Viviparous Breeding Oviparous
Habit Terrestrial Habit Terrestrial Habit Terrestrial
Status Least concern light brown Status Not evaluated Status Least concern
bands
Location C. and S.E. USA Location N. South America Location S.E. Asia

The copperhead is boldly marked triangular This is one of the most dangerous dark triangular
with chestnut-brown or orange bands head snakes in South America because of markings
on a gray, tan, or pinkish background. its rapid strike, potent venom, and its
In spring and fall, it basks during the vision, but it also has distinctive tendency to live near human habitations. wedge-shaped
day, but it becomes nocturnal “eyelashes,” formed by raised scales Heat-sensitive pits between the eyes marking behind each eye
in summer. This viper lies practically above its eyes. Active at night, it preys and nostrils enable it to detect prey
hidden among dead leaves or rocks on lizards, frogs, and small rodents, and in the darkness. It is also called the This highly venomous snake, usually
waiting to ambush rodents, frogs, lies in wait near forest flowers to catch fer-de-lance, though some reserve found at the edges of forests and in
hummingbirds as they come to feed. this name for a West Indian species clearings, is quick to strike, and is the
Bothriechis schlegelii Eyelash pit vipers vary greatly in color, that has a similarly pointed head. Males cause of many snake-bite fatalities in
ranging from an intense orange-yellow have longer tails than females, and Southeast Asia. It is purplish brown,
Eyelash pit viper to grayish green. may fight during the breeding season.
Females may give birth to up to 100 with light-edged, darker
Length 18 – 30 in young. Juveniles have brightly colored triangles on its flanks,
(45 – 75 cm) tail tips, which they use to lure prey. and has a pointed snout.
Breeding Viviparous A nocturnal hunter, the
Habit Arboreal irregular dark Malaysian pit viper uses the
Status Not evaluated blotches heat pits between its eyes and
nostrils to help it to locate prey in
REPTILES Location Central America, the dark. Unlike most vipers, this
N. South America species lays eggs—the female may
lay 2 clutches of 13 – 25 eggs each
This tropical forest snake is one of a in a year—and remains coiled around
number of pit vipers that live in trees. them throughout their incubation.
Like most arboreal snakes, it has a
prehensile tail and good binocular

Crotalus durissus Crotalus cerastes MOVING ON SAND Lachesis muta

Tropical rattlesnake Sidewinder Sidewinding is a form of movement Bushmaster
used by several snake species
Length 31⁄4 ft (1 m), Length 18 – 32 in that live on loose sand. Instead of Length 81⁄4 ft (2.5 m),
max 5 ft (1.5 m) (45 – 80 cm) sliding forward, with its body in max 12 ft (3.6 m)
Breeding Viviparous Breeding Viviparous contact with the sand, a sidewinding Breeding Oviparous
Habit Terrestrial Habit Terrestrial snake throws itself over the surface, Habit Terrestrial
Status Least concern Status Least concern following a diagonal path. This kind Status Not evaluated
of movement creates characteristic Location S. Central
Location Central America, Location S.W. USA, parallel tracks. America, N. South America
South America N.W. Mexico
flattened body The bushmaster is the longest viper
strongly keeled scales The sidewinder is the stoutest of all in the world. It is also one of the most
rattlesnakes and is the only one in which venomous, with a 20 percent mortality
The bite of the tropical rattlesnake is the female is smaller than the male. It has rate, even if treated; however, it generally
highly venomous—about 75 percent a highly distinctive way of moving—an avoids contact with humans. A secretive
of untreated bites result in fatalities. adaptation to life on windblown desert species, it ambushes prey at night—
There are 14 subspecies recognized, sand. It feeds mainly on small lizards coiled and ready to strike—along a
with highly variable coloring, but this and rodents, often ambushing its prey mammal trail. It has a slender, yellow or
is the only rattlesnake over much of its from the cover of isolated shrubs. tan body with black markings. Unusually
range. Heavily built, it has a broad head Although sidewinders can be for a viper, females lay eggs (about
and obvious heat-sensitive pits, to detect aggressive, by rattlesnake 8 – 15), guarding them until they hatch.
prey in total darkness. This nocturnal standards their bite is not
species spends the day coiled, partly especially dangerous.
hidden by vegetation. The female Their young are born
gives birth to 6 – 12 young. in late summer, in
clutches of 6 – 12.

BODY COLORATION
The sidewinder varies from
cream, gray, tan, or brown to
pinkish, depending on the soil on
which it lives; markings are poorly defined.

BLIND AND THREAD SNAKES 407

Trimeresurus albolabris in a favored hunting place waiting for Tropidolaemus wagleri has various color combinations: usually
prey to come within range, then drawing black, with green or yellow crossbars
White-lipped pit back its head when ready to strike. Its Wagler’s viper and scattered yellow spots. Juveniles
viper bite is painful, but the venom is mild and are green, with yellow and/or red spots
rarely fatal to humans. Females give Length 21⁄2 – 41⁄4 ft arranged into vague crossbands; some
Length 231⁄2 – 39 in birth to 10 – 11 young. (0.8 – 1.3 m) individuals retain their juvenile markings
(60 – 100 cm) Breeding Viviparous throughout their lives. Although its bite
Breeding Viviparous scattered Habit Arboreal is painful, it is seldom fatal to humans.
Habit Arboreal yellow scales Status Least concern
Status Least concern BURROWER
heat pits Location S.E. Asia A thread snake above ground
is an uncommon sight. This Peters
Location S.E. Asia thread snake from southern Africa has
emerged from its burrow in sandy soil.
This slender-bodied snake—easily Renowned for living in semicaptivity
confused with several other green in Malaysia’s Penang Snake Temple,
pit vipers from the same part of the this highly variable snake is sluggish
world—has a wide, rounded head during the day, when it rests in trees.
with prominent heat pits. It lives in At night, it ambushes small mammals,
trees, hanging head-down at night birds, lizards, and frogs by hanging
head-down from the branches. It is a
thickset viper, with a chunky head, and

Blind and thread snakes

PHYLUM Chordata These small snakes live underground,
CLASS Reptilia emerging above the surface only when
ORDER Squamata driven out by lack of food or by flooding.
They have a slender, cylindrical body
SUBORDER Serpentes and are covered with smooth, shiny

SUPERFAMILY Scolecophidia scales that allow them to move easily

FAMILIES 5 through sand and soil. Their skull REPTILES

SPECIES 441 is more heavily built than in other

snakes, and they have jaws that

they cannot open widely, with few teeth. Their eyes

are covered with scales and are barely functional.

Blind and thread snakes are restricted to tropical

and subtropical regions. They are often found within

ant and termite mounds, and the bulk of their diet

is composed of these insects and their larvae.

Rena dulcis scale-covered eyes are all features Tetracheilostoma carlae Indotyphlops braminus
associated with a burrowing lifestyle.
Texas thread snake This snake feeds opportunistically on Barbados thread Brahminy blind
small insects and spiders, and also snake snake
Length 6 – 101⁄2 in enters ant and termite nests in search
(15 – 27 cm) of larvae. When the snake enters a nest, Length Up to 4 in Length 6 – 7 in
Breeding Oviparous it releases pheromones that imitate that (10 cm) (15 – 18 cm)
Habit Burrowing of the insects. The “soldiers,” deceived Breeding Oviparous Breeding Oviparous
Status Least concern into thinking that the snake is part of the Habit Burrowing Habit Burrowing
nest, allow it to enter and feed in safety. Status Critically Status Not evaluated
Location S. USA, The chief predators of the Texas thread endangered
N.E. Mexico snake are other snakes and nocturnal
birds and mammals. The female lays
2 – 7 eggs and coils around them Location Caribbean Location W. Asia to
until they hatch. N. Australia. Widely
introduced elsewhere
silvery sheen
The slender-bodied, pinkish brown Texas This tiny snake was described in This is the only snake known to
thread snake lives almost exclusively 2008. It is only found on the upland be parthenogenetic. Males have
below the ground, coming to the surface forest of central Barbados. The larger never been found, and females
only at night and after rain. The smooth and recently introduced brahminy lay their eggs without having to
scales, short tail, and vestigial, thread snake, which breeds more mate. Each egg is about the size
quickly, could be an important of a peanut. The snake’s habit of
competitor and threaten its survival. stowing away in plant pots has
The Barbados thread snake is the resulted in the spread of this species
smallest known snake—and has throughout warm parts of the world.
probably evolved to the lowest Its scale-covered eyes, blunt
possible size limit for any snake. It snout, and smooth scales
lays a single, highly elongated egg, are all features adapted
which hatches into a youngster that to burrowing. If in
is already half the length of an adult danger, this snake may
snake. A related species found only give off an unpleasant,
on St. Lucia island could be the pungent fluid.
world’s second smallest snake.

408 LIZARDS

Lizards

PHYLUM Chordata Lizards are the most successful group Regeneration
CLASS Reptilia of reptiles. They form a large and varied
ORDER Squamata group that is not easy to define concisely: Some lizards are able to voluntarily break off part of their tail, a phenomenon

known as autotomy. This is a defense mechanism that helps the lizard

SUBORDER Lacertilia although a typical lizard has a distinct escape when grabbed by the tail. To add to the effectiveness of the strategy,

the tail may be brightly colored, often blue, to draw the attacker’s attention away

FAMILIES 37 head, 4 well-developed limbs, and a long from the head. The tail may also continue to move for several minutes

SPECIES About 6,300 tail, there are exceptions to all of these after being severed, apparently to distract the predator. The tail breaks at

generalizations. Some lizards also have one of several predetermined weak points (see below), and it does not have

to be pulled in order to cause a break. Most lizards can regrow a broken tail,

CLASSIFICATION NOTE an unusual ability to shed their tail when but the replacement will not have the same join between fracture plane
scale arrangement or coloration as the vertebrae within vertebra
The classification of lizards, like attacked by a predator and then regenerate original. A lizard may shed its tail several
that of snakes, is the subject it. Most species reproduce by laying eggs,
of much debate, especially although some give birth to live young; times during its lifetime.
the way they are grouped into a small number actively care for their
families. However, their division offspring. Lizards have adapted to survive FRACTURE PLANES
into the following superfamilies in habitats all over the world (although they
is widely accepted: are not found in Antarctica). Most live on A lizard’s tail breaks at one of several
the ground, on low-lying rocks, or in trees. weak points, called fracture planes,
Iguanas and relatives There is also a small number of burrowing across certain vertebrae. The muscles
see pp.410 – 6 are arranged in such a way that they,
too, will come apart neatly.
Geckos and snake-lizards
see pp.417 – 9

Skinks and relatives
see pp.420 – 5

Anguimorph lizards
see pp.426 – 30

species and even one that feeds in seawater. A few lizards,

notably the geckos, have adapted to live around humans, NEW GROWTH

and in some parts of the world, they are a common sight This viviparous lizard has shed its tail and
grown a replacement. The point at which the
REPTILES on the walls and ceilings of buildings. old tail was broken can be identified by
the change in scale color.

DESERT LIZARDS

Deserts are an important habitat for lizards, such as these
web-footed geckos. Like all reptiles, they do not require large
amounts of water because they use only small amounts to
expel waste. Most of the water they need is obtained from
dew and fog. Webbed toes allow them to walk on soft sand.

Anatomy SENSES toe with FEET AND CLAWS
sharp claw
In addition to a distinct head, 4 legs, and a tail, most lizards A lizard’s senses are adapted to Most lizards have 5 digits on each foot. Many
have external ear openings, and eyelids that can be opened its lifestyle. Many species that live species (particularly those that climb, such as
and closed. However, some lizards have short legs or none at underground cannot see, while
all. There are also forms with no eyes or no ears, while others those living above ground may this monitor lizard) have sharp claws. Most
have eyes covered by a transparent scale rather than movable have good vision, but only a few lizards cannot oppose their digits,
lids. The tongue may be short or long and is usually are able to see colors. Lizards with although chameleons have their
notched at the tip; forked tongues are found in external eardrums can hear digits fused into 2 opposing groups,
some species. A lizard’s scales may be large, airborne sounds.
smooth, and overlapping or small, rough, enabling them to grip branches.
and studlike, in almost any combination.
Many have irregular scales or a few external ear nostril LEGLESS LIZARDS
large scales scattered among many opening eyes on
smaller ones, but none has the single side of Over time, some lizards (such
row of wide ventral scales characteristic head as this Burton’s snake-lizard)
of snakes (see p.384). Most lizards have lost their limbs. This is
have sharp teeth along the edges an adaptation that helps them
of their jaws. to move easily through soil
burrows, sand, and leaf litter.

LIZARDS 409

Movement head moves
slightly
Most lizards move by walking, climbing, or
burrowing. When walking, they usually use all tail swings
4 limbs (see right), although some species lift widely from
their front legs off the ground while running at side to side
high speed; basilisk lizards can even run for
short distances over the surface of water in WALKING
this way, helped by broad feet that spread A lizard’s limbs are held at right angles to the body,
their weight. Some lizards are agile climbers. rather than supporting it from underneath. This
To improve their grip, they may have long, means that as the lizard walks, the weight
sharp claws, while some have a prehensile of the body is thrown from side to side,
tail. Among the most impressive climbers are resulting in a characteristic wiggling
geckos, which can cling to smooth, vertical motion and causing its tail to swing
or even overhanging surfaces using adhesive and provide a counterbalance.
pads on the tips of their digits (see p.417).
Burrowing lizards may use powerful front
limbs for digging, although others have
reduced limbs or no limbs at all and simply
force their way through loose soil and sand
with rapid “swimming” movements. A few
lizards can glide from high trees (see below).

flap of skin long,
supported by whiplike tail
long ribs

FLYING REPTILES

The flying lizard (above) has
flaps of skin, that act like wings,
stretched between elongated ribs. Some
other species have similar flaps between
their toes. In all cases, the lizards move
from tree to tree by gliding rather than
powered flight.

CLIMBING TREES

Some large lizards, such as this perentie
(right), are surprisingly agile climbers.
Perenties usually climb only to escape
predators, but other lizards, especially
chameleons, spend the greater part of
their lives in trees.

CAMOUFLAGE Defense

Chameleons (such as the Cape dwarf chameleon, left) Lizards use various active and passive strategies
have a remarkable ability to alter the appearance of to avoid the many other animals that prey upon them.
their skin. Not only does the color change, but markings, Other than running away, passive strategies include
such as lines and bars, may appear and disappear. camouflage and mimicry of inanimate objects, such
as sticks and leaves. Some species can alter their
FIGHTING DRAGONS coloration, while others make themselves inconspicuous
by pressing their bodies close to rocks or tree trunks
The Komodo dragon (right) is the largest of all to avoid casting a shadow. Active strategies include the
lizards. When attacking its prey, it usually relies voluntary loss of the tail (see Regeneration, opposite),
on its jagged teeth and sharp claws. However, and threat displays, which often involve warning coloration
when defending itself from another member of (as in blue-tongued skinks) or body enlargement (as in
its own species, it will often turn its back and the frilled lizard). Large species, such as monitors,
thrash its powerful tail. as well as some smaller ones, defend themselves
by biting, scratching, or lashing their tail. Two species
of lizards, the Gila monster and the Mexican beaded
lizard, are venomous.

410 LIZARDS

Iguanas and relatives

PHYLUM Chordata Iguanas and their relatives include some of the most colorful
CLASS Reptilia and familiar of all lizards. Along with geckos and snake-lizards,
ORDER Squamata they are also the most primitive. They are divided into 3 groups:
iguanids, agamids, and chameleons. Many species, notably
SUBORDER Lacertilia chameleons, are capable of changing their skin color. Some
SUPERFAMILY Iguania are highly territorial or have elaborate social rituals. Iguanids
and agamids look similar to each other but are found in different
FAMILIES 14 parts of the world: iguanids occur throughout the Americas, in
SPECIES 1,840

Madagascar, and on a few Pacific islands, while agamids are

found in Africa, Asia, and Australasia. Chameleons occur in Africa, Madagascar,

Asia, and Europe. Iguanas and their relatives occupy various habitats, including

desert, grassland, and rain forest. Most species lay eggs but a small number give

birth to live young.

REPTILES Anatomy season. Females may change color
according to whether or not they are
Iguanids and agamids look alike and receptive to males: once they have
occupy similar ecological niches. The mated, they often develop orange
main difference between them is in spots (known as gravid coloration) to
the teeth: unlike iguanids, the agamids deter unwanted attention from males.
have teeth that are fixed to the
jawbone and not replaced if lost. Most Communication
species have small scales and a loose
fold of skin (or dewlap) under the In many species of iguanas and their
head. The males are often brightly relatives, the males use their bright
colored, and many species have coloration for display, both to females
ornamentation on their head and a and to other males. Often occupying
crest down their back. They may also a prominent vantage point, they will
have a brightly colored throat fan, nod their head vigorously or bob
which they use for communication. up and down, sometimes exposing
brightly colored scales on their
Chameleons are adapted to life in throat and chest. Males are highly
the trees. Their narrow body and territorial, and will chase off other
leaflike profile help make them males and mate with any
inconspicuous among foliage, while a receptive female that lives
prehensile tail and toes that are fused in or strays into their territory.
in 2 opposing groups enable them to
hold tightly to branches. Chameleons HUNTING
also have a well-known (but often
exaggerated) ability to change color Chameleons, such as this veiled chameleon, stalk their
(see below). Male chameleons usually prey slowly, locating it by sight. Each eye can swivel
have a crest or horns on their head. independently in any direction and is supported on a
turret. The muscular tongue is extremely long with
Color change a thick, adhesive tip. When prey is within range, the
chameleon flicks its tongue out at great speed, catching
Two types of color change can the prey on the tip and pulling it back into its mouth.
be seen in the lizards in this group.
Chameleons change color by
expanding or contracting pigment
cells (chromatophores) scattered
in their skin. When the cells are
expanded, the skin darkens due to
the dispersal of melanin pigments
in the cells; as the cells are contracted,
the skin becomes lighter. A great
number of different colors and
patterns can be produced in this way.
Chameleons change color mainly
to control their temperature (making
themselves darker when they need
to warm up) or to communicate with
other members of their species, rather
than for camouflage. At night, while
they are asleep, chameleons always
become paler. Small leaf chameleons
and pygmy chameleons, which
are brown, have limited ability to
change color.

Agamids and iguanids also change
color, but this takes place more slowly
than in chameleons. Mature males
become brighter in the breeding

IGUANAS AND RELATIVES 411

Acanthosaura crucigera it may open its mouth wide and Agama agama Calotes versicolor
bite if cornered. It has long, thin limbs,
Boulenger’s a long tail, a crest of spines on its Rainbow lizard Variable garden
pricklenape lizard back, and larger spines on the nape lizard
of the neck and over the eyes. The Length 12 – 16 in
Length 10 – 12 in male is larger, more colorful, and (30 – 40 cm) Length 12 – 14 in
(26 – 30 cm) has a more pronounced crest than Breeding Oviparous (30 – 35 cm)
Breeding Oviparous the female. This lizard lies in wait for Habit Terrestrial Breeding Oviparous
Habit Arboreal insects, then suddenly darts out to Status Not evaluated Habit Terrestrial
Status Not evaluated catch them. Females lay 10 – 12 eggs Status Not evaluated
at a time in leaf litter or debris. Location W., C., and
E. Africa

Location S.E. Asia Location W. Asia to
E. and S.E. Asia
black “mask” black collar
around eyes around throat

Relying on its greenish yellow, Male rainbow lizards are among Africa’s strongly keeled
cryptic coloring, this lizard often most conspicuous reptiles. At night, they body scales
escapes detection from predators are drab and gray, but when they warm up
by remaining motionless, although in the sun, they develop a bright orange This long-tailed
head, and a blue or turquoise body. lizard is one of
Chlamydosaurus kingii CLIMBING TO SAFETY the most common
Females and juveniles are quite different, species in southern Asia, thriving in
Frilled lizard with a gray coloration that makes good farmland and gardens as well as in natural
camouflage. Rainbow lizards live in habitats. Its color is highly variable, but
Length 231⁄2 – 28 in open habitats, and are often seen breeding males always have a red area
(60 – 70 cm) around buildings. They feed on insects around the mouth and throat—a feature
Breeding Oviparous but become omnivorous when food is that explains why this lizard is sometimes
Habit Terrestrial short. Males have a head-bobbing known as the bloodsucker. Variable
Status Least concern garden lizards are good climbers, and hunt
courtship display, and females insects and other small animals by lying in
lay 5–7 eggs in holes in wait, then lunging at their prey. There are
the ground. many similar species throughout Asia.

Location S. New Guinea,
N. Australia

brightly long, thin tail REPTILES
coloured male
Australia is home to a wide range of
lizards, but this species is the most Frilled lizards forage mainly on the Draco spilonotus outward and opens the flaps of skin,
spectacular. Its name derives from ground. They are good climbers, closing them again on landing. It is
the large, leathery frill around its neck, and after carrying out their defensive Flying lizard generally tan or pale brown, with a
which is normally folded back over the throat flap for display that is large and
animal’s shoulders. However, if the display they usually run up Length 6 – 8 in bright yellow in the male, but small
lizard is threatened, it opens the frill a tree trunk, heading (15 – 20 cm) and pale yellow in the female. Highly
like an umbrella, and at the same for the highest Breeding Oviparous agile, this lizard lives on tree trunks and
time rocks its body and hisses branches. Habit Highly arboreal actively hunts for ants. Females only
through its gaping mouth. Status Not evaluated leave the safety of trees to lay 8 – 12
This display is often enough eggs, which they bury in sand or soil.
to deter would-be Location S.E. Asia
predators, allowing the
frilled lizard to make orange The flying lizard has a pair of “wings,” “wings” aid
its escape. patches at consisting of skin stretched between gliding between
base of frill elongated ribs, which help it glide from tree trunks
DEFENSIVE BLUFF one tree trunk to another to avoid
This lizard’s frill consists of a flap of predators such as snakes and birds.
skin strengthened by rods of cartilage. To take off, the lizard moves its ribs
It is often brightly colored, contrasting
with the animal’s gray or brown body.

Hypsilurus spinipes tail. It can “freeze” to avoid detection— Hydrosaurus pustulatus (8 cm) high, which helps the
a useful tactic against predators lizard swim. When in danger from
Southern angle-headed such as birds, mammals, and monitor Sailfin lizard predators, mainly birds of prey, this
lizard lizards—and its exceptionally long lizard dashes away at great speed,
toes and claws enable it to climb Length 32 – 39 in often diving into water to escape.
Length 8 – 13 in trees rapidly to escape from danger (80 – 100 cm) At other times, it may bask on branches
(20 – 33 cm) on the ground. An active forager, the Breeding Oviparous that overhang or are near
Breeding Oviparous southern angle-headed lizard lunges Habit Arboreal streams. It forages for
Habit Arboreal quickly and suddenly at insects, its Status Vulnerable leaves and fruit, and
Status Not evaluated sole food source. The female lays eggs feeds on insects
in depressions in soil or in leaf litter. Location Philippines opportunistically.

Location Australia As an adult, this large, gray
(S.E. Queensland and or greenish gray lizard has
N.E. New South Wales) a well-developed crest of
toothlike scales from the
This lizard is characterized by nape of the neck down
a large, angular head, a raised the back. The tail also
crest (more prominent in males) has a crest, up to 31⁄4 in
on the nape and back, and a long

412 LIZARDS

Moloch horridus spines on its head and back, and Physignathus cocincinus when hunted by snakes and birds of
much smaller ones on its legs and prey. It hunts primarily by ambushing its
Thorny devil feet. Such protection is vital for the Asian water dragon prey, which comprises invertebrates and
thorny devil because, unlike most small vertebrates such as lizards;
Length 6 – 7 in lizards, it spends a lot of time foraging Length 21⁄2 – 31⁄4 ft however, it also forages actively for food,
(15 – 18 cm) in one place on the ground, leaving (80 – 100 cm) and may occasionally graze upon
Breeding Oviparous it vulnerable to attack while feeding. Breeding Oviparous vegetation. Females lay multiple clutches
Habit Terrestrial Like the desert horned lizard (see p.416), Habit Terrestrial of 10 – 15 eggs throughout an extended
Status Not evaluated which shares a similar way of life, Status Not evaluated breeding season, in burrows or shallow
Location W. to C. Australia the thorny devil feeds during scrapes, and cover the eggs
the day, when ants are on Location S.E. Asia with soil and leaves.
Although it is not often seen—partly the move, and can consume (Thailand, Cambodia, and
because it is well camouflaged— up to 2,500 insects during Vietnam) hump on neck and
the buff, tan, or gray thorny devil is a single meal, catching crest along back
instantly recognizable by its squat them with its projecting The Asian water dragon is a large lizard larger in male
shape, its slow way of moving, rocking tongue. Females lay 3 – 10 with a crest of prominent, toothlike scales
backward and forward as it walks, and eggs in underground from neck to tail and a raised hump on its pinkish
its armory of sharp spines. These cover burrows in summer. neck. It has a green body, but the chin chin and
the whole of its body, with the largest and throat are white, pale yellow, or neck
black-edged, dark pinkish. Males become brighter in color
short brown markings during the breeding season. This lizard
head typically basks near water, into which it
may flee for safety, especially

REPTILES long hindlimbs for
rapid movement

Pogona vitticeps and foraging for small insects and are territorial. The female lays several Bradypodion thamnobates
vegetation near its regular perch. If clutches of 15 – 30, and occasionally
Central bearded confronted by a predator—usually birds more, eggs throughout the breeding Natal Midlands
dragon of prey, monitor lizards, or snakes—it season, burying them in sandy soil. dwarf chameleon
erects its black throat frill, or “beard,” The hatchlings’ body markings are
Length 12 – 18 in and presents a wide, open mouth. more distinctive than those of adults, Length 6 – 71⁄2 in
(30 – 45 cm) The males, and even the females, but they do not possess a beard. (15 – 19 cm)
Breeding Oviparous Breeding Viviparous
Habit Semiarboreal broad, scales of varying Habit Arboreal
Status Not evaluated triangular head sizes and shapes Status Near threatened

Location Australia grayish body Location Southern Africa
with light and (Kwa-Zulu Natal)
dark markings

This bulky lizard inhabits dry forest, Dwarf chameleons are largely
woodland, and scrubland, resting on restricted to southern Africa,
stumps or raised humps on the ground, where they live in forest and
scrub. They differ from most
Uromastyx acanthinura It may also use its tail as a club and may consists of insects and plants, and other chameleons in giving birth
bite if cornered. Males, and occasionally it may walk over 2⁄3 mile to live young. The Natal Midlands
North African females, are aggressively territorial. The (1 km), zigzagging across dwarf chameleon is a typical species,
mastigure coloration of this lizard varies according rocky outcrops in the with a high protuberance, or casque,
to temperature: gray or yellowish brown desert, to find favored plant species. covering its neck. Its coloration is
Location N. Africa Length 12 – 16 in in cold weather, when it hibernates, Females lay at least 2 clutches of 20 – 30 highly variable, but the long-tailed
(30 – 40 cm) changing to orange, red, yellow, or green eggs a year, then bury them in side males, which are often green, are more
Breeding Oviparous when active. It emerges only on warm chambers off the main colorful than the females and juveniles,
Habit Terrestrial/ days, basking and orienting its body burrow, smoothing which are brown or gray. Like other
Burrowing to the sun, until its body temperature over the nest to chameleons, it is specially adapted for
Status Not evaluated is high enough for foraging. Its diet disguise the site. life in trees, and feeds on insects, which
it captures with its long, sticky tongue.
tail covered very small
with whorls scales conical scales form
of spiny scales crest on back

The North African mastigura has a
short, thick, armored tail that it
uses to block the entrance to
its burrow to deter predatory
birds or mammals. Inside
the burrow, it inflates its
body to wedge itself in.

IGUANAS AND RELATIVES 413

Brookesia micra Furcifer pardalis CHANGING COLOR

Micro leaf chameleon Panther chameleon Chameleons are famous
for being able to change
Length 11⁄16 in Length 16 – 201⁄2 in color for camouflage, but
(30 mm) (40 – 52 cm) in most species, color is
Breeding Oviparous Breeding Oviparous equally important as a
Habit Partly arboreal Habit Arboreal means of communication.
Status Near threatened Status Least concern Male panther chameleons
attract females by producing
Location N. Madagascar Location Reunion Island, sudden flushes of color,
E. and N. Madagascar while females change
color when pregnant to
Thought to be the smallest reptile in the Madagascar and its neighboring islands signal that they are not
world, this tiny chameleon was found in have over 70 species of chameleons, receptive to mating.
2012 on a small islet off the north coast which is more than in any similarly sized
of Madagascar. It lives on the rainforest region of the world. The panther tongues, which can be longer than the territories. Each year, females
floor among leaf litter, and feeds on small chameleon, particularly the adult male, rest of their bodies. They are usually lay several clutches of 12 – 50
invertebrates. Males, which are slightly is one of the most brightly colored, with slow-moving, but at the onset of the eggs, burying them in
smaller than females, cling to the a bewildering array of breeding season, males fight for moist soil.
female’s back and are carried around by color schemes, including
her until she is ready to mate. The eggs green, brick-red, highly bright lateral prehensile tail
are about 2.5mm long. turquoise, or any variable stripe usually
combination of these hues. coloration present
juvenile It can change its color rapidly,
but it usually retains its bright FLATTENED SNOUT
lateral stripe. Panther chameleons live One of the larger chameleons,
in lightly wooded, scrubby habitats, the panther chameleon has a bony,
and catch insects and other small flattened region on top of its snout,
animals by shooting out their sticky fringed with enlarged scales. The male
has a small nasal appendage, while the
female (shown left) has none.

Furcifer oustaleti Trioceros jacksonii HORNLESS FEMALE Calumma parsonii REPTILES

Oustalet’s chameleon Jackson’s chameleon Parson’s chameleon

Length 20 – 27 in Length 8 – 12 in Length 20 – 231⁄2 in
(50 – 68 cm) (20 – 30 cm) (50 – 60 cm)
Breeding Oviparous Breeding Viviparous Breeding Oviparous
Habit Arboreal Habit Arboreal Habit Arboreal
Status Least concern Status Least concern Status Near threatened

Location Madagascar Location E. Africa, Location N. and E.
introduced in Hawaii Madagascar

larger casque With their 3 forward-pointing horns, Male and female Jackson’s This very large, deep-bodied chameleon
on male males of this species are among the chameleons are easily told apart: is usually greenish, but may also be
most distinctive of all chameleons, and the female (shown above) is usually blue. The male is larger and more
fused at one time were often caught and sold stockier than the male, and the colorful than the female, with a larger
toes for gripping, horns are tiny or absent. casque (protuberance) on the top of
common to all as pets. Both sexes have a flattened the head and a warty, flattened horn—
chameleons body and serrated crest along over the neck. absent in females—on the snout.
the back, with a bony casque Their normal Parson’s chameleon lives mainly in
The largest of all the chameleons, color is green, the trees and is slow-moving, relying
this species is rather dull in color— serrated but specimens that on camouflage to escape detection.
brown with a few yellow, red, or crest along live in East Africa’s Defensive behavior includes inflating its
greenish spots—and has no horns. the back mountain forests are body, hissing, or biting, and it may
However, it has a large, flattened usually brighter and larger become more brightly colored. Males of
casque (protuberance) over its head than ones that live lower this species are highly territorial, and
and neck. Unusually for a chameleon, down. Jackson’s chameleon mate with receptive females without
the male is less colorful than the relies primarily on its camouflage preliminaries. The female lays 16 – 38
female, but he becomes more flushed to avoid being attacked. However, eggs, burying them in a hole dug
with color during courtship. Females if cornered, it inflates its body and in moist soil.
lay approximately 50 eggs, in soil or gives a menacing hiss. Females are
leaf litter. Slow and deliberate in its live-bearing, producing 2 litters of up leaf-shaped
movements, Oustalet’s chameleon to 50 young each year. Newborns are body adapted to
carefully stalks prey such as insects light brown, but turn green at about arboreal existence
and small vertebrates before capturing 4 months. In males, horns start
them with its extendible, sticky tongue. to form about 2 months later.
It defends itself against predatory In the wild, the lifespan of
snakes and birds by inflating its body, Jackson’s chameleon is
presenting its side to the enemy, and probably 2 – 3 years.
opening its mouth wide; it may also
hiss and bite. HORNS ON MALE
The male Jackson’s chameleon
has 3 long, pointed, bony horns on
the front of his head, used in fights
with other males over territory.

414 LIZARDS

Corytophanes cristatus KEY FEATURES extended casque extends Crotaphytus collaris
pouch from top of
Helmeted iguana The high, narrow casque head to neck Collared lizard
on the head distinguishes
Length 12 – 16 in this iguana from all other head small Length 8 – 14 in
(30 – 40 cm) lizards in tropical America; in relation (20 – 35 cm)
Breeding Oviparous the precise function of to casque Breeding Oviparous
Habit Arboreal this casque, or “helmet,” Habit Terrestrial
Status Least concern is unknown. When this Status Least concern
iguana is defending its
Location S. Mexico to territory, it extends the Location C. and S. USA,
N. South America pouch under its head to N. Mexico
ward off other animals.

The most distinctive feature of the of prey or snakes. It feeds on insects, The brown or greenish brown collared
helmeted iguana is the high, narrow remaining still until they come within lizard is distinguished by the black and
casque that extends from the head to the range, then darting out to white markings around its neck. It has
nape of the neck. Other characteristics catch them. Females long hind legs that enable it to flee rapidly
include long, spindly legs, a narrow body, lay eggs in leaf from danger, often to retreat to a burrow
and a long, thin tail. A crest of small, litter or soil. or beneath a boulder; the front limbs may
toothlike scales runs along the back and leave the ground entirely when it runs
top of the tail. This iguana relies heavily fast. Active only on hot days, this lizard
on camouflage for defense, and runs perches on rocks looking for insects and
away when threatened, usually by birds smaller lizards. Its strong jaws can crush
even large prey, and may also be used to
FOREST CAMOUFLAGE bite in defense. Females develop orange
The helmeted iguana can change color
voluntarily, like a chameleon, from greenish patches when carrying their eggs,
to tan, brown, or black, helping it to escape which they lay in burrows
detection in its tropical forest habitat. or under rocks.

long,
spindly legs

REPTILES Anolis carolinensis Anole lizards are found only in the staying in place with the help of Females lay one egg at a time, in
Americas. There are over 400 species, expanded pads on its toes. Although leaf litter and moist plant debris, at
Green anole and most—including this one—are normally bright green in color, it frequent intervals throughout
slender animals with long tails and legs, turns brown when it rests in shade— the breeding season.
Length 43⁄4 – 8 in and distinctive display fans beneath their which explains why it is sometimes
(12 – 20 cm) throats. Like many of its relatives, the erroneously called a chameleon. Both extended
Breeding Oviparous green anole is a tree dweller, feeding sexes possess the pink, extendible throat fan
Habit Arboreal mainly on insects. It sleeps in bushes at throat fan. Males use theirs more
Status Least concern night, but during the day often basks on often, signaling to rivals and
vertical surfaces such as palm fronds, potential mates.
Location S.E. USA tree trunks, fence posts, and walls,

Amblyrhynchus cristatus together on the same stretch of shore. laying 1 – 6 eggs in sandy burrows. After Conolophus marthae
During the breeding season, males fight an incubation period of 2 – 3 months, the
Marine iguana aggressively for the opportunity to mate. young emerge to feed in the intertidal Galapagos pink
Suitable nesting sites are scarce, so zone and hide in rock crevices to escape land iguana
Length 20 – 39 in thousands of females often nest together, attack from gulls and other seabirds.
(50 – 100 cm) Length 39 in
Breeding Oviparous larger crest VARYING NEIGHBORS (100 cm)
Habit Semiaquatic on male Marine iguanas often have a “whitewashed” Breeding Oviparous
Status Vulnerable look, which comes from salt expelled by their Habit Terrestrial
salt encrusted nasal glands. There is great variation in adult Status Critically
Location Galapagos on skin weight between islands: on Fernandina Island, endangered
Islands
males can be over 24 lb (11 kg), while
on Genovesa, they rarely Location Galapagos
reach 2 1⁄4 lb (1 kg). Islands

The marine iguana, with its large, scaly Described in 2009, this iguana is found
head and back, is the only lizard that only on Volcan Wolf on Isabela Island
forages for food in the sea. It dives and possibly fewer than 100 individuals
for algae in the cold waters off the exist. DNA evidence suggests that it
Galapagos Islands, and its body is diverged from other Galapagos land
specially adapted to cope with both
cold and with excess salt. Large adults iguanas around 5.7
may dive down to 39 ft (12 m) and can million years ago.
stay underwater for over an hour, but
under normal conditions they feed
during shallow dives lasting less than
10 minutes. When not feeding, marine
iguanas warm up by basking on rocks,
and often several thousand can be seen

IGUANAS AND RELATIVES 415

Laemanctus longipes This extremely slender iguana is green Basiliscus plumifrons WALKING ON WATER

Casque-headed with a yellow face—coloration that Green basilisk
iguana
provides excellent camouflage among

foliage. Its long legs and claws are

adapted for climbing, enabling it to Length 231⁄2 – 30 in
(60 – 75 cm)
escape rapidly up tree trunks when Breeding Oviparous
Habit Arboreal
Length 16 – 28 in threatened by predatory birds and Status Least concern
(40 – 70 cm)
Breeding Oviparous snakes. It sits and waits for insects
Habit Arboreal
Status Not evaluated casque on to come within Location Central America
head points range, then
backward darts out to

Location S. Mexico to catch them. The
Nicaragua
female lays 3 – 5 The green basilisk lives in trees
bordering ponds, streams, and
eggs at a time in The green basilisk—bright green or rivers. When threatened, it drops
bluish green in coloration—rests on from its perch and dives into the
spindly shallow scrapes branches and in shrubs, waiting for water to escape. This basilisk has
legs in soil or leaf litter. insects and small vertebrates before the unique ability to run across
darting out to catch them. Males are the surface of standing water on
Anolis sagrei However, although it can change body very territorial; a single male may hold its hind feet, thus earning itself
color, its range is limited to brown territory containing a harem of females another common name—the
Brown anole or gray. Both sexes have an orange with whom he mates. Females lay about Jesus Christ lizard.
throat fan with a white border, which 20 eggs in a season. Green basilisks
Length 6 – 8 in the males use during courtship can live up to 10 years in captivity.
(15 – 20 cm) displays. This anole is common on
walls, climbing with the help of adhesive
Breeding Oviparous pads on its toes. It forages for flies crest crest bright green yellow eyes
and other insects, but it is less active on tail on back body
Habit Terrestrial/ in winter, and is hunted by larger lizards, CHARACTERISTIC CRESTS
Arboreal snakes, and birds. Females lay one The green basilisk has 3 crests,
egg at a time throughout spring and located on its head, back, and tail.
Location S. Mexico to Status Not evaluated summer. This is a short-lived lizard, The back and tail crests aid
with a lifespan of only 2 – 3 years. swimming, helping this lizard
Central America, Caribbean However, it is prolific and adaptable, escape predators.
and quick to colonize new areas, often
In shape, this lizard (also known as the ousting the native anole species. REPTILES
Cuban anole) closely resembles its
relative the green anole (see opposite).

Cyclura cornuta Iguana iguana ARBOREAL ADAPTATION

Rhinoceros iguana Green iguana The grayish or green coloration of
this large iguana provides excellent

Length 31⁄4 – 4 ft Length 31⁄4 ft (1 m), camouflage in the tall forest trees in
(1 – 1.2 m) max 61⁄2 ft (2 m) which it lives. It has long legs, and
Breeding Oviparous Breeding Oviparous its long claws are specially adapted
Habit Terrestrial Habit Arboreal to aid climbing. Since this lizard
Status Vulnerable Status Endangered usually lives beside rivers, it

Location Caribbean Location Central America, may drop into the water from
N. South America overhanging branches to escape

from predatory birds or mammals.

Shown here are a male (on the

The massive gray rhinoceros iguana left)—easily identified by the large,
is characterized by several enlarged,
raised scales that resemble horns The green iguana is one of the largest fleshy dewlap beneath his throat,
on the snout of the adult. It walks
ponderously, with its head held up, lizards in the Americas. Generally used for display—and a female
foraging for leaves and fruit, but
can run very fast when fleeing from grayish or green—although some local green iguana. Adult males are
danger. When threatened, it may thrash
its tail and bite in defense. Males are populations are orange—it has stout highly territorial.
larger than females, with larger horns
and crests, and are highly territorial. legs, a long tail, and a crest of toothlike
Females lay 2 – 20 eggs in burrows and
guard them aggressively. All 8 species scales down its back. Adults also have a
of Cyclura lizards are endangered due
to habitat destruction and predation fleshy dewlap beneath the throat, which
from introduced mammals such as
pigs, dogs, rats, cats, and mongooses. is large in males. Juveniles eat a

crest of wider range of food than green coloration
pointed scales for camouflage
adults, including insects
dewlap
as well as fruit, long claws for
climbing and defense
flowers, and leaves. HEAVY WEIGHT
The average green iguana weighs
Green iguanas up to 11 lb (5 kg), but an exceptional
defend themselves specimen may weigh up to 22 lb
by lashing out (10 kg). Despite their predatory
with their tails and appearance, adults are almost entirely
claws. Females lay herbivorous, often feeding high in trees.
up to 40 eggs in an

underground chamber,

producing several clutches

through an extended breeding

season. There is no parental care:

newly hatched youngsters have to

fend for themselves. Despite being long tail long legs
hunted for food and collected for used as for climbing
the pet trade, the green iguana is whip in
defense
still abundant in parts of its range.

416 LIZARDS

Ctenosaura similis Sauromalus obesus Phrynosoma platyrhinos lizard is relatively smooth-skinned
compared to some of its relatives,
Black spiny- Chuckwalla Desert horned lizard but has large “horns” on its head,
tailed iguana and smaller spikes on its back and
Length 11 – 161⁄2 in Length 3 – 51⁄4 in tail. Its coloration—gray, reddish, or
Length 28 – 39 in (28 – 42 cm) (7.5 – 13.5 cm) tan—helps to conceal it on sandy
(70 – 100 cm) Breeding Oviparous Breeding Oviparous or gravelly ground, as it moves around
Breeding Oviparous Habit Terrestrial Habit Terrestrial slowly searching for food. When it
Habit Terrestrial Status Least concern Status Least concern locates a column of ants, it feeds
Status Least concern voraciously, picking them up with its
Location S.W. USA, Location S.W. USA extendible tongue. If it is threatened
N.W. Mexico with attack, by birds or carnivorous
mammals for example, its first reaction
Location S. Mexico, is to “freeze” (it is capable of remaining
Central America motionless for long periods). If picked
up, it inflates its body with air. Females
tail thick head black The desert horned lizard is one of nest in burrows in sand or loose earth,
at base in male 16 closely related species that are laying 2 clutches of up to 16 eggs each
breeding season. Because these lizards
The juvenile black spiny-tailed scattered across dry habitats in North have a round, flat shape, they warm
iguana is bright green, lives in trees, and Central America. Often known up quickly in the morning sunshine.
and is hunted by birds of prey. The as horned toads, because of their They hibernate during the winter.
adult, which has few if any predators, spiky scales and round, squat shape,
is large and gray, with a spikier tail these lizards specialize in feeding on
than the juvenile. Adults bask on ants, and rely primarily on camouflage
rocks or stumps, looking out for for protection. The desert horned
invertebrates and insects, and
also forage for leaves, fruit, This lizard employs an unusual wavy crossbands
carrion, and scraps. Capable of form of defense: it retreats into rocky
great speed when running away, crevices and jams itself in by inflating
this iguana may also bite in defense. the folds of loose skin on its neck,
Females lay 20 – 30 eggs in burrows throat, and flanks, making it hard for
or among tree roots. predatory birds and mammals to pull
it out. It requires very hot conditions
pointed head spiky tail used before it becomes active, and remains
as weapon in the crevices in cold weather. In
hot weather, it emerges to bask and
REPTILES forage for fruit, leaves, and flowers of “horns” large short, rapidly
succulent plants. Females lay 5 – 16 on head stomach tapering tail
eggs, often only in alternate years.

Sceloporus occidentalis Oplurus cuvieri Liolaemus tenuis held stiffly over its back. The large, green
scales on its body overlap like roof tiles.
Western fence lizard Madagascan Chilean swift Chilean swifts live in small groups on
collared iguana trees, with one male and several females
Length 6 – 9 in Length 71⁄2 – 12 in occupying a territory. Females lay their
(15 – 23 cm) Length 12 – 141⁄2 in (19 – 30 cm)
Breeding Oviparous (30 – 37 cm) Breeding Oviparous eggs in a communal site, often under
Habit Terrestrial Breeding Oviparous Habit Mostly arboreal bark; over 400 eggs have been
Status Least concern Habit Arboreal Status Least concern found in a single site. This lizard
Status Least concern hibernates during winter.

Location S.W. USA, Location S.W. South
N.W. Mexico America

Location Madagascar,
Grand Comoro Island

raised, This is a thickset lizard with a chunky Also known as the thin lizard, the
pointed head and spiny tail. Its body is grayish Chilean swift has a tail that is nearly
scales brown, with a distinctive black collar, twice as long as its body. It stalks its
and speckled brown markings. Males insect prey—mainly flies—with the tail
The main are more intensely colored than females.
distinguishing Tropidurus hispidus and crevices in rocky outcrops, an
feature of this The Madagascan collared iguana
common lizard is remains motionless for much of the Guianan lava lizard effective form of protection against
the blue patches on its underside time on a tree trunk, waiting for an
and throat. In the western fence lizard, insect to come into range before predators such as birds, snakes, and
the blue color is most pronounced darting out to catch it. When
in the males, and may be faint or entirely threatened by birds of prey or larger lizards. The dark color of this
absent in females and juveniles. Western snakes, it retreats into cracks and
fence lizards typically sit on rocks, crevices in the trunk, using its tail Length 5 – 7 in lizard probably helps it to warm up
fences, and other prominent places, to form a barrier between itself and (13 – 18 cm)
bobbing up and down to display their Breeding Oviparous quickly as it basks in the sun, usually
markings to rivals or to potential mates. the predator. Females lay 4 – 6 eggs Habit Terrestrial
Highly active, they forage for insects, in a season. Status Not evaluated on vertical surfaces. It forages actively
and in between feeding bouts they bask
in the sun. Females usually lay a single protective, for insects and spiders. Females lay
clutch of 3 – 14 eggs. spiny tail
Location N. South flat head 3 or more clutches
America of 4 – 6 eggs in

a year.

The Guianan lava lizard is dark brown
to black above and white below, with
a black collar around the neck. Its flat
shape allows it to hide in narrow cracks

GECKOS AND SNAKE-LIZARDS 417

Geckos and snake-lizards

PHYLUM Chordata Geckos are small, vocal, usually nocturnal lizards. Some are agile climbers, a communal egg-laying site, which
CLASS Reptilia capable of finding purchase on smooth, vertical, or even overhanging surfaces, can contain several dozen incubating
ORDER Squamata including tree trunks, rock faces, and walls and ceilings. There are also many eggs as well as the remnants of
desert species, most of which live in burrows or rock crevices, emerging at night hatched ones. A few species give
SUBORDER Lacertilia to forage on the ground. Geckos are cosmopolitan lizards, found in most tropical birth to pairs of live young. Many
SUPERFAMILY Gekkota and subtropical countries and on many oceanic islands. This group also includes demonstrate temperature-dependent
2 types of legless lizards that are found only in Australasia. Snake-lizards, which sex determination: males are born
FAMILIES 7 have scaly flaps in place of legs, live on the ground, while blind lizards have eyes at higher temperatures,
SPECIES 1,700 that are covered with scales, and live in underground burrows. above 88° F (31° C),
and females at
Anatomy vertical surfaces or even to hang upside snakes by their external ear lower ones.
down. Some geckos (from the family openings and the several rows
Most geckos are small, slender lizards Gekkonidae) do not have functional of scales along their underside. CLIMBING
with a relatively large, flat head and eyelids; instead, their eyes are covered Aided by the microscopic structures on
large eyes with vertical pupils. Day with a transparent scale, as in snakes, Reproduction their toe pads, geckos can climb almost
geckos are often brightly colored, which they keep clean with their any surface. This makes it possible for
whereas the more typical nocturnal tongue. Others (from the family Geckos’ successful spread them to hunt for food in places where few
geckos are dull gray or brown to help Eublephaeidae) do have eyelids and around the world may be other land-dwelling animals can reach.
them blend in with their surroundings. can blink—they are mostly ground partly due to their resilient,
Some also have extraordinary shapes dwellers from deserts, but some live hard-shelled, and sticky REPTILES
with, for example, leaflike tails to in caves and one is arboreal. Geckos eggs, which can become
help them with camouflage. are unique among lizards in producing attached to uprooted
an array of sounds that are used to trees and drifting
Climbing geckos often have long attract mates or to defend territory. debris. Most species
claws and sometimes flattened pads at lay eggs in pairs but
the end of each toe. These toe pads, Snake lizards are long and slender, some small geckos
usually absent in ground-dwelling and may have pointed snouts. Like lay a single egg
species, are made of thousands of some geckos, they lack functional at a time. Several
microscopic structures that provide eyelids, but can be distinguished from females may use
adhesion, allowing them to climb

Coleonyx variegatus translucent, its tiny scales giving a silky Eublepharis macularius discarded in defense, but not as readily
texture to its skin. A secretive, nocturnal as in some other lizards. This gecko
Western banded lizard, it hides during the day in rock Common forages at night. It shelters from
gecko crevices, and actively forages at night for leopard gecko extreme heat and cold in burrows
small insects and spiders. When captured, or under rocks, hibernates in winter,
Length 43⁄4 – 6 in it squeaks and may discard its tail. Other Length 8 – 10 in and may estivate in summer. It has
(12 – 15 cm) defense tactics involve raising its body and (20 – 25 cm) been known to live up to 25 years
Breeding Oviparous curling its tail over its back to look bigger Breeding Oviparous in captivity.
Habit Terrestrial and, possibly, to mimic a scorpion. Habit Burrowing
Status Least concern Females lay 2 soft-shelled eggs at a time. Status Not evaluated warts on
back and tail
Location S.W. USA, dark bands broken prominent Location S. Asia
N.W. Mexico into patches eyes black spots
or bars on
Unlike typical geckos, the The common leopard gecko has a thick yellow body
western banded gecko has tail that is used to store food. In times
prominent eyes with movable of plenty, the tail increases in size, but broad head
lids. It appears delicate and it shrinks during droughts, when the of male
surplus food is metabolized. It may be
movable
eyelids

Hemitheconyx caudicinctus It has a tan body with dark brown Cyrtodactylus hontreensis gecko species
bands across the back and a broad, endemic to the
African fat-tailed dark brown head. Males have a bulge Hon Tre bent-toed island and the second that belongs
gecko at the base of the tail. A shy animal gecko to the genus Cyrtodactylus. However,
with a lifespan of about 25 years, it lives scientists believe there are many more
Length 6 in (15 cm), in dry savanna, rocky hillsides, or river Length 5 in species of geckos that have yet to be
max 10 in (25 cm) banks, retreating during the day into (13 cm) discovered. The Hon Tre bent-toed
Breeding Oviparous burrows and actively foraging for Breeding Oviparous lizard is pale pink in color, with 5 or so
Habit Terrestrial insects at night. It estivates in the Habit Cave-climbing darker, broad, white-edged bands that
Status Least concern dry season. This gecko sometimes Status Not evaluated transverse the length of its slender
bites or discards its tail in defense. body from its neck to the base of its
tail. It also has 14 irregularly arranged,
Location W. Africa Location Vietnam longitudinal rows of low, smooth
tubercles running along the middle
dark brown bands region of its body. It belongs
to a large genus of “bow-fingered”
thick tail geckos with delicate birdlike feet
armed with claws—enabling it to grip
The tail of the African fat- Known only from the cave system of the rocky surfaces of its habitat. Its
tailed gecko is used as a Kien Giang Biosphere Reserve on habits are, so far, little known.
food-storage organ; when Vietnam’s Hon Tre Island, this
the lizard is well fed, its
tail becomes thicker. stout distinctively patterned gecko was
body discovered in 2006. It is one of 5 new

418 LIZARDS

Gekko gecko TOE PADS Gonatodes daudini Gonatodes vittatus

Tokay Union Island gecko Striped day gecko

Location S.E. Asia Length 7 – 14 in Length 1½ – 13⁄4 in Length 23⁄4 – 3 in
(18 – 36 cm) (4 – 4.5 cm) (7 – 7.5 cm)
Breeding Oviparous Breeding Oviparous Breeding Oviparous
Habit Mostly arboreal Habit Terrestrial Habit Terrestrial
Status Not evaluated Status Critically Status Least concern
endangered
Location Caribbean Location N.W. South
America

This gecko is named after the male’s Like most climbing geckos, the Confined to the isolated dry forest of The male striped day gecko is tan,
loud, explosive call that sounds like tokay has expanded, adhesive toe Union Island in the St. Vincent and with a black-edged white stripe from
“to-kay.” It is often found in dwellings, pads that enable it to gain a firm Grenadines group in the Caribbean, this the snout to the tail, while the female
hiding during the day and emerging foothold and move quickly and tiny, red-eyed gecko with enlarged body is gray-brown, with an indistinct white
in the evening to hunt. When easily over vertical surfaces such scales was discovered in rotten wood on stripe (both are shown below). In both
threatened by snakes and small, as walls and tree trunks. Mount Taboi in 2005 at an altitude of sexes, the eyes lie toward the top of
nocturnal mammals, it delivers a 490 ft (150 m). Unlike other tiny members the head. This diurnal gecko lives
hard bite and, if grasped, it discards territorial and cannibalistic, eating of the genus, this species spends most on the ground among leaf litter, but is
its tail. The male tokay, which has a other tokays as well as insects of its time on the ground. Historically, the also a good climber. It is quick to snap
larger head than the female, is highly and other small vertebrates. The species probably had a wider distribution up small insects or spiders. Females
male mates with several females. in upland dry forest of the Lesser often nest together in a communal site,
NIGHT SIGHT The females then attach a pair of Antilles—a habitat now cleared through where they lay 2 (rarely single) eggs,
The tokay is a large, blue or grayish blue spherical, hard-shelled eggs to a much of this range. Confined to an area each approximately the size of a
nocturnal species with large, yellow eyes that vertical surface, often behind bark, of less than 4 square miles (10 square dried pea.
enable it to see well in the dark. The vertical or in a crevice or a cavity in a wall. km), the Union Island gecko is now
pupils close to a slit with 3 “pinholes” in daylight. in imminent danger of extinction.
orange spots
on body

REPTILES Hemidactylus frenatus numbers. It can climb smooth, vertical Phelsuma madagascariensis Ptenopus garrulus
surfaces and cling upside down to
Common house ceilings. Rarely seen during the day, Madagascar day Common barking
gecko the common house gecko hunts for gecko gecko
insects, spiders, or smaller geckos
Length 43⁄4 – 6 in that gather near electric lights after Length 9 – 12 in Length 21⁄4 – 4 in
(12 – 15 cm) dark; it defends its hunting area. When (22 – 30 cm) (6 – 10 cm)
Breeding Oviparous captured, it squeaks and discards its Breeding Oviparous Breeding Oviparous
Habit Mostly arboreal tail readily to escape. Habit Arboreal Habit Terrestrial
Status Least concern Status Least concern Status Least concern

Location Tropical regions Location N. Madagascar Location Southern Africa
worldwide

This widespread, adaptable, gray or The largest of the green day geckos, this
brown gecko mostly inhabits buildings, thickset lizard inhabits tree trunks and
but may also be found on and under walls, perching (often head down) on
rocks and in tree trunks, often in large vertical surfaces with the aid of its toe
pads. If it successfully evades attack
Pachydactylus rangei the day in long tunnels that it from birds, it can live 10 years or more. A conspicuous feature of many
digs in the sand, emerging to deserts in southern Africa is the sound
Web-footed gecko forage at night. Due to lack Small groups occupy a single tree, and of the male common barking gecko
of water in the desert, it drinks several females may lay eggs in the same calling from the mouth of its burrow
Length 43⁄4 – 51⁄2 in the water that condenses on site, under bark or in crevices. Males after dusk. Both sexes have rounded
(12 – 14 cm) its skin on foggy nights. When heads, with a blunt snout, and are
Breeding Oviparous threatened, it raises itself on have a swelling at the base of the yellow or grayish yellow, with darker
Habit Terrestrial stiffened legs to appear larger. tail, and reproductive females brown or reddish brown spots; their
Status Not evaluated have calcium deposits that toes are long and strongly fringed with
irregular are visible through the scales. When in danger, this gecko
Location W. southern Africa dark markings skin of their throat. may “freeze,” relying on camouflage
to avoid detection by predators.
pink, red spots Alternatively, it may retreat into
frail body on back its complex burrow system.
large eyes with fine,
This pink gecko is noted for its webbed red reticulations well-developed
toes, which enable it to run across toe pads aid
desert dunes without sinking into the climbing
loose, windblown sand. It spends

GECKOS AND SNAKE-LIZARDS 419

Ptychozoon kuhli FLYING FEET Rhacodactylus leachianus forest trees, rarely venturing down
to the ground. As with most geckos,
Kuhl’s flying gecko New Caledonian it eats insects and small vertebrates,
gecko but it also feeds on fruit. It uses its
Length 7 – 8 in powerful jaws to crush food, as well
(18 – 20 cm) Length 12 – 14 in as to deliver a painful bite in defense.
Breeding Oviparous (30 – 35 cm) New Caledonian geckos appear to live
Habit Arboreal Breeding Oviparous in small family groups that comprise
Status Not evaluated Habit Arboreal a single male, one or more females,
Status Least concern and their young. Females lay eggs
Location S.E. Asia in tree holes, behind bark.

Location New Caledonia thick, clawed
toes with
This tropical forest gecko is one of Unlike the flying lizard (see p.411), fine scales on adhesive pads
several lizards that escape danger by Kuhl’s flying gecko glides mainly velvetlike skin
jumping from trees and gliding through with its strongly webbed feet. Its
the air. When not airborne, it often fall through the air is also controlled This is an extremely
rests head down on tree trunks—a by flaps of skin along its flanks, large gecko that
posture that allows rapid takeoff. It is and its flattened, frilly- can reach as much
exceptionally well camouflaged—even edged tail. as 16 in (40 cm) in
by gecko standards—and feeds mainly length, although it is usually
on insects, ambushing or stalking its tail with
prey. Females lay 2 eggs each time scalloped smaller. Mottled brown, with
they breed. fringe a large head and eyes, and a
small, thin tail, it lives on tall

flaps Sphaerodactylus elegans catching small insects with a quick
of skin dart. Although mainly diurnal, it may
Ashy gecko also be active at night, often near street
COLORED FOR lights. Females lay one egg at a time
CAMOUFLAGE Length 23⁄4 – 3 in in communal nests—behind bark,
Mainly brown or (7 – 7.5 cm) among dead leaves, or in crevices.
grayish brown, with Breeding Oviparous
indistinct, dark, mottled Habit Terrestrial REPTILES
markings, Kuhl’s flying gecko Status Not evaluated
is a nocturnal lizard that remains
motionless during the day, relying webbed Location Caribbean
on camouflage to escape detection. toes

Stenodactylus sthenodactylus Tarentola mauritanica This tiny gecko is brown, with very fine,
speckled white markings and a pointed
Elegant sand gecko Moorish gecko snout. A lively but short-lived animal,
it forages constantly among leaf litter
Length 31⁄2 – 41⁄4 in Length 4 – 61⁄2 in and debris in woods and near houses,
(9 – 10.5 cm) (10 – 16 cm)
Breeding Oviparous Breeding Oviparous Saltuarius cornutus leaflike tail, which can be shed if
Habit Terrestrial Habit Terrestrial the animal is attacked (males have
Status Not evaluated Status Least concern Northern leaf-tailed a paired bulge at the base of their
gecko tail). This gecko is practically invisible
Location N. and E. Africa, Location S. Europe, when resting on tree trunks and
W. Asia W. Asia, N. Africa among foliage in its tropical forest
habitat, and only gives itself away
This dainty-looking lizard has long The stocky, grayish or brown Moorish Length 6 – 81⁄2 in when it moves. Males are territorial,
limbs, a thin tail, and a slender, beige or gecko often occurs in high densities (15 – 21 cm) and females lay 2 eggs at a time in
sand-colored body, with darker bands in rocky scrub, drystone walls, and Breeding Oviparous cracks behind bark. Northern leaf-tailed
and small, pale spots on its back. Its eyes buildings; it occupies vertical surfaces, Habit Arboreal geckos feed mainly at night, actively
are large, and it has a slightly upturned and seldom moves far from a crack into Status Least concern foraging for insects, which make up
snout. A skillful digger, the elegant which it can retreat. Active mainly at most of their diet.
sand gecko lives in holes in the ground night, in cooler weather it may also be Location E. Australia
or under stones, and buries its eggs active during the day, and it hibernates triangular head
in the sand. It becomes active at dusk, in winter. This gecko frequently waits in
when it hunts for termites, ants, small likely hunting areas, often near lights, Geckos are generally noted
moths, and small beetles and their and pounces on insects, such as moths, for their camouflage, but this
larvae, walking with a stiff-legged that come near. Females may nest eastern Australian species
gait to gain a better view of the excels at this form of defense.
surroundings. If threatened, communally, laying their eggs behind It has cryptic, gray mottled
usually by birds, this gecko may flaking rock or plaster, or in crevices. coloration, a flattened
arch its back to appear larger. body that is shaped to
rough scales on tail eliminate shadows,
and a remarkably
large, wartlike
scales on back

flattened leaf-shaped tail long
body limbs
long, thin, clawed
flat head toes for climbing
on rough tree bark

420 LIZARDS

Skinks and relatives Reproduction

PHYLUM Chordata Skinks and their relatives form the largest Girdled and plated lizards have large, Skinks reproduce in various ways.
CLASS Reptilia group of lizards. The skinks are mostly long rectangular scales, each of which has Some species lay eggs, whereas
ORDER Squamata and slender, and some species are without a raised keel. This keel may be drawn others give birth to live young. In a
legs. Some have a method of reproduction out into a point in girdled lizards, few species, the developing embryo
SUBORDER Lacertilia that is unique among lizards, the females especially on the scales behind the is nourished by the female via a
SUPERFAMILY Scincomorpha nourishing their developing young via a head and on the tail, which is used to primitive placenta. In others, the
placenta. Skinks occur throughout the world form a barricade when the lizard is female lays eggs and guards them
FAMILIES 8 but are most numerous in tropical and pursued into a burrow or crevice, or during incubation by coiling herself
SPECIES 2,477 even as a weapon. When threatened around them. She may also move the
by a predator, the armadillo lizard eggs if danger threatens. When the
subtropical areas. Most live on the ground, grasps its tail in its mouth, presenting young hatch, the female licks them
the attacker with a spiky hoop that it clean, and they may remain near
often in leaf litter, but there are also arboreal and burrowing cannot easily attack. her for the first few days.

species. The other families in this group are the girdled and Whiptails and tegus have small Some of the relatives of skinks,
scales, a slender body, a pointed snout, notably a group of whiptails and
plated lizards, whiptails and tegus, and wall and night lizards. and long limbs, although this family also another of wall lizards, are
includes some legless forms. Tegus are parthenogenetic—that is, they can
Like the skinks, most of these are ground-dwelling lizards. generally larger than whiptails. reproduce without males. In these
species, each young is an exact
Anatomy Some skinks have small legs or no Wall and sand lizards are replica (clone) of the mother, and
legs at all, an adaptation to burrowing outwardly similar to whiptails, is therefore also female, producing
Skinks are typically elongated, with or living in dense vegetation, such although they are found in parts eggs of its own as soon as it reaches
a slightly flattened body, a long tail, as turf. When attacked, skinks readily of Europe, Asia, and Africa, whereas maturity. Some species are entirely
and a small, wedge-shaped head with discard their tail, which is sometimes whiptails are restricted to the parthenogenetic; in others, there are
small eyes. Burrowing species may brightly colored to deflect the Americas. Many members of both some populations that include males
have permanently fused, transparent attention of predators from their head families are brightly colored, and and reproduce normally.
eyelids, which allow them to see while and body. they are all prepared to sacrifice
burrowing, and no ear openings. their tail if necessary.

REPTILES FEEDING

Most ground-living skinks are secretive animals that
spend most of their time under the cover of leaf litter.
They generally forage during daylight and take shelter
under logs or stones at night. Small skinks feed on
invertebrates. The larger species (including the major
skink, shown here) also eat plant matter, and some
may even eat rodents and birds.

SKINKS AND RELATIVES 421

Ouroborus cataphractus in family groups—the female gives birth Cordylus giganteus Cordylus rhodesianus
to one or 2 large young, and may even
Armadillo lizard feed them—a characteristic that is Sungazer Zimbabwe
unusual among lizards, which rarely girdled lizard
Length 61⁄2 – 81⁄2 in demonstrate parental care. Insects Length 11 – 151⁄2 in
(16 – 21 cm) and spiders make up most of the diet (28 – 39 cm) Length 43⁄4 – 63⁄4 in
Breeding Viviparous of the armadillo lizard and it, in turn, Breeding Viviparous (12 – 17 cm)
Habit Terrestrial is hunted by a variety of predators, Habit Terrestrial Breeding Viviparous
Status Vulnerable including birds of prey. It can live for Status Vulnerable Habit Terrestrial
up to 25 years in captivity, slightly Status Not evaluated
Location Southern Africa more in some exceptional cases. Location Southern Africa

protective spines Location Southern Africa
on neck
The armadillo lizard is covered with Also known as the giant girdled lizard, This olive-brown lizard is often found
stout, defensive spines on its neck tail caught the yellowish to dark brown sungazer in kopjes—the piles of eroded rock that
and tail and squarish scales on in mouth can often be seen basking at the are scattered across southern Africa’s
its back. When threatened, it entrance to its burrow, apparently grasslands. Its flattened body enables it
grasps its tail in its mouth staring at the sun. Burrows usually to hide in narrow cracks or under rocks
and forms a ring with face north or northwest, providing when threatened, and it uses its tail,
its body, presenting maximum sunshine throughout the which is covered in rings of pointed
the spines to deter an scales, to block the cracks and deter
approaching predator day. This lizard possesses an predators such as snakes, birds, and
and making it awkward armored tail, ringed with pointed mammals. The Zimbabwe girdled lizard
to attack. Armadillo scales and resembling a pinecone, lives in small family groups—with the
lizards occur in scrub which it can use to block the young remaining near the parents—and
and rocky outcrops, entrance to its burrow. If grasped, hibernates in winter.
hiding in large cracks, it wedges the long spines on its
and hibernating in head and neck into the burrow keeled, slightly
winter. They live roof, making its body difficult to spiny, scales
extract. Its diet consists of insects
yellowish and small vertebrates. Females REPTILES
brown color give birth to one or 2 young,
which remain
body formed into near the adults.
protective ring The sungazer
hibernates during
the winter months.

Gerrhosaurus major wedge itself into cracks in rocky flowers, invertebrates, and small Lacerta agilis
outcrops for protection against birds vertebrates, including smaller lizards.
Rough-scaled of prey, snakes, and small mammals. The male is highly territorial, particularly Sand lizard
plated lizard This lizard is light to medium brown, during the breeding season, when he
but the male develops a pinkish throat fights with other males. The female lays Length 7 – 9 in
Length 16 – 19 in in the breeding season. An active 2 – 4 relatively large, oval eggs in rock (18 – 22 cm)
(40 – 48 cm) forager, its diet comprises fruit, crevices, in moist soil, and under logs. Breeding Oviparous
Breeding Oviparous Habit Terrestrial
Habit Terrestrial light to medium long tail Status Least concern
Status Not evaluated brown body
Location Europe to C. Asia
Location C., E., and
southern Africa This stocky lizard belongs to a group of
species that are common in Europe and
The body of the rough-scaled plated rectangular plates fold of skin Asia, sometimes extending north of the
lizard is covered with rectangular plates, cover body along sides Arctic Circle. In Great Britain, it is found
arranged in rows, that help the reptile in pastures and sand dunes, but farther
south, it lives in a much wider range
Platysaurus broadleyi Once wedged in, it is almost impossible boulders and under exfoliating flakes of habitats, including gardens. It has
to extract. This lizard spends most of of rock, especially where leaves a blunt head and relatively short legs,
Broadley’s flat lizard the day hunting for insects, especially or debris have accumulated. and its color is very variable, although
the small black flies that swarm near males are at their brightest during the
Length 6 – 8 in waterfalls, darting rapidly to catch blue head breeding season. Sand lizards feed on
(15 – 20 cm) the flies when they land, or leaping of male small insects and spiders, and rapidly
Breeding Oviparous upward to catch them in flight. It also shed their tails if they are attacked,
Habit Terrestrial eats ripe berries. The male has a bluish extremely usually by snakes, birds, or mammals,
Status Not evaluated head, green back, yellow or orange flat body especially domestic cats. Females lay
front limbs, and an orange-tan tail. clutches of 3 – 14 eggs in the spring and
Location Southern Africa The female and juveniles have dark summer, and adults hibernate in winter.
(Augrabies Falls) brown backs with 3 cream stripes
and a pale yellow tail. The female lays grass green
2 clutches of 2 eggs each summer, coloration of male
in deep cracks between large
The extremely flattened head, body,
and tail of this lizard enable it to
squeeze into very narrow rock crevices
to escape from predatory birds of
prey, particularly the rock kestrel.

422 LIZARDS

Lacerta schreiberi scattered, small black spots, and a Zootoca vivipara BREAKING OUT
blue throat or head (sometimes both)
Schreiber’s green in the breeding season. The female is Viviparous lizard
lizard brown or bright green, with large black
markings and a brown head. The Length 4 – 43⁄4 in
Length 14 in young are green with white or yellow, (10 – 12 cm)
(36 cm) black-edged bars on their flanks. This Breeding Viviparous
Breeding Oviparous lizard can be found basking in the open Habit Terrestrial
Habit Mostly terrestrial in fields, moorland, or hillsides, often Status Least concern
Status Near threatened near streams, occupying a position with
a good, all-around view. It mostly sits Location Europe to C. and
and waits for insects to come within E. Asia (including Japan)
range, but also forages in cracks. When
Location S.W. Europe disturbed, it retreats into a burrow or Young viviparous lizards are born in
dives into water, hiding under stones on
the streambed. If attacked, it can easily an egg membrane from which they
discard its tail. This lizard has a lifespan
of over 10 years in captivity. The female escape almost immediately. They
lays 6 – 12 eggs at a time.
Also known as the common lizard, this are about 11⁄2 in (4 cm) long and

Schreiber’s green lizard is typical of the species has one of the largest continuous black. In the southern parts of their
numerous localized species of “wall
lizards” that are found in different parts ranges of any terrestrial reptile, reaching range—in the Pyrenees—viviparous
of Europe. The male is green, with
well into the Arctic. It is the only lizards sometimes lay eggs.

member of its genus that bears live

young—an adaptation that

helps it survive in regions that

are too cold for eggs to

develop. In the far north of its

range, it can hibernate for up to thick pregnant
8 months at a time and may breed neck female
only every second or third summer;

however, it makes up for this by COLORS AND PATTERNING
having a relatively long lifespan. Although the viviparous lizard is usually brown or
Viviparous lizards live on the olive, some specimens are entirely black or light
ground, usually in dense brown. Males tend to be spotted, while the
vegetation, and feed mainly on
insects and spiders. They often female (shown) is usually striped.

bask on a sunny bank, flattening their

REPTILES body and spreading out their legs.

Timon lepidus large insects, birds’ eggs, nestlings, Podarcis pityusensis Chalcides ocellatus
other lizards, and small mammals.
Eyed lizard Although it hibernates in winter, it may Ibiza wall lizard Eyed skink
emerge on warm days. If grasped, it
Length 16 – 32 in bites, discards its tail, and retreats into Length 6 – 81⁄2 in Length 12 in
(40 – 80 cm) its burrow. Females lay a single clutch (15 – 21 cm) (30 cm)
Breeding Oviparous of 6 – 16 eggs a year. Breeding Oviparous Breeding Oviparous
Habit Terrestrial Habit Terrestrial Habit Burrowing
Status Near threatened dark blue markings Status Near threatened Status Not evaluated
on body
Location S.W. Europe Location Balearic Islands Location S. Europe, N.
and N.E. Africa, W. Asia

Also known as the ocellated or jeweled head with pointed snout Also known as the ocellated
lizard, this thickset green animal, with tail twice as skink, the eyed skink has a stocky,
blue eyespots running along its flanks, long as body light brown or yellowish brown body
is Europe’s largest lizard. It inhabits with small, white eyespots surrounded
hillsides, fields, With its slender body and long toes, by black. Its smooth, glossy scales
and clearings, the Ibiza wall lizard is an agile climber. and small limbs are adaptations to a
foraging for It is most often seen basking on burrowing lifestyle. Although this lizard
walls, rocky slopes, and fallen trees— is mainly active during the day, it may
Podarcis lilfordi sparse and food is scarce, posing the sometimes in large numbers—but also be active at dusk in very hot
greatest threat to this lizard’s survival. it invariably scuttles away rapidly if weather. It is often found basking near
Lilford’s lizard It is an active forager, scrambling over disturbed. Males are generally blue old ruins or drystone walls near olive
rocks and shrubs in a relentless search with black markings, while females groves, never straying far from cover.
Length 7 – 9 in for food—insects, fishes dropped often have dark stripes, but the If threatened by birds, snakes, and cats,
(18 – 22 cm) by seabirds, and food discarded by colors and patterns of both sexes vary it darts into its burrow or into crevices
Breeding Oviparous tourists, as well as flowers and leaves. across the species’ between rocks; if attacked, it may shed
Habit Terrestrial Some populations are entirely black, range. Wall lizards feed its tail. An active forager, the eyed skink
Status Endangered while others are brown or green. searches under stones for small insects
The female lays about 4 eggs in on insects, and they lay and spiders. It lives in loose colonies, and
Location Balearic Islands crevices filled with soil or leaves, their eggs in burrows or the female lays 3 – 10 eggs.
or under shrubs. under stones. The Ibiza
This tough, adaptable lizard can wall lizard can live for small limbs aid head narrower
survive in remarkably hostile turnip-shaped tail up to 6 years. burrowing than body
environments. Although it has stores fat
few predators (there are no
snakes on many of the no distinct neck
islands it inhabits),
vegetation is

SKINKS AND RELATIVES 423

Corucia zebrata is a long-lived species. Although little is Lamprolepis smaragdina the foliage of large forest trees, and
known about its reproductive and social actively forages for insects, which it
Solomon Islands behavior, it is likely to be monogamous Emerald tree skink catches in a rapid, darting movement. If
tree skink and appears to live in small family groups attacked by birds of prey or snakes—its
or loose colonies. Males and, to some Length 7 – 10 in main predators—this lizard will shed
Length Up to 30 in extent, females are highly territorial. A (18 – 25 cm) its tail in order to escape from its
(75 cm) female gives birth to one, occasionally Breeding Oviparous aggressor. Males are territorial and
Breeding Viviparous 2, huge young—about one-third of the Habit Arboreal females lay 9 – 14 eggs.
Habit Arboreal size of the adult—which stays with its Status Not evaluated
Status Not evaluated very protective mother for several neck, short head, and muscular limbs.
weeks or even months. The low Location S.E. Asia, New Its coloration is dark brown, becoming
reproductive potential of this skink Guinea, Pacific islands darker on the flanks, with a white,
makes it vulnerable, although it is not yellow, or orange underside. The
Location Solomon Islands currently a protected species. body scales are smooth and glossy,
and there are fine lines running down
This olive-green or grayish wedge-shaped The bright green emerald tree skink its back. The major skink can be seen
green skink is a highly head has a stocky body with a long, tapering basking in the sun or foraging for
tail, a pointed snout, and smooth, shiny insects and small vertebrates during
unusual lizard in many scales. It lives on the trunks and among the day around the bases of large,
buttressed trees, logs, or near rocky
ways. It is very large, outcrops, never too far from cover.
Females give birth to up to 6 young,
with a massive, which have scattered white dots on
their flanks—these spots disappear
wedge-shaped head Bellatorias frerei as the lizard matures. Within Australia,
the major skink is commonly found in
and a long, prehensile Major skink forests in northeast New South Wales,
islands of the Torres Straits, and
tail. Unlike other skinks, Arnhem Land (Northern Territory).

the Solomon Islands tree skink well-developed
limbs
is entirely herbivorous, feeding clawed toes Length 231⁄2 – 28 in
exclusively on leaves and fruit in its for climbing (60 – 70 cm)
Breeding Viviparous
forest habitat. Active at night, it shelters Habit Terrestrial
Status Not evaluated
in tree holes during the day. If threatened

or provoked, it will hiss while raising long, Location S. New Guinea,
itself up, and may even bite. This skink rounded tail N. and E. Australia

Eumeces schneideri on its blue-gray back. It is The major skink is one of 20 closely REPTILES
often found in cultivated land and related species that are found in
Berber skink semidesert, where it digs burrows at Australia and New Guinea. Like
the base of shrubs. When attacked, it most of its relatives, it has a chunky
Length 16 – 18 in retreats into its burrow, or may jump appearance, with a body that is
(40 – 45 cm) into water. Active and quick-moving, the squarish in cross section, a thick
Breeding Oviparous Berber skink forages for insects, spiders,
Location N. Africa to Habit Terrestrial/ snails, and smaller lizards. It shelters
W. Asia Burrowing from the sun in the middle of the day
Status Not evaluated and may not emerge on cold winter
days. Females lay 3 – 20 eggs, coiling
around them until they hatch.

The Berber skink is the largest member shiny, smooth,
of its genus, which is found in scattered orange
North Africa, the Middle East, scales
Asia, and the Americas.
Bulky and with a squarish
cross section, it has
distinctive orange scales

Plestiodon lagunensis scuttling about among Eutropis longicaudata coastal scrub. An active forager,
leaf litter or vegetation—where it frequently pokes its snout into leaf
Pink-tailed skink it searches for insects and spiders— Long-tailed skink litter and debris where insects and
or hiding under stones. It is active spiders may be found. Little is known
Length 61⁄2 – 8 in year-round, although less so during Baja Length 12 – 14 in about its reproductive behavior, but
(16 – 20 cm) California’s brief winters. The female lays (30 – 35 cm) most related species give birth to 5 – 10
Breeding Oviparous 2 – 6 eggs in tunnels in loose soil. She Breeding Viviparous young. The genus Eutropis, to which
Habit Terrestrial stays with them until they hatch, and may Habit Terrestrial it belongs, contains egg-laying as
Status Least concern even move them if they are threatened by Status Not evaluated well as live-bearing species.
unfavorable conditions, such as floods.
Location Mexico (Baja
California) dark brown
back with
cream stripes Location S.E. Asia

Also known as the San Lucas skink, bright The most distinctive feature of this
this species is characterized by a long, pink tail of slender skink is its extremely long tail,
pink tail that is bright in juveniles but juvenile which can be up to twice the length of
faded in adults. The reason for this the body and head combined. The
coloration is unclear, but it may help to body scales are shiny and brown,
divert predators toward the tail—which and the flanks are darker brown or
can be discarded—instead of toward black. This lizard lives in clearings and
more vulnerable parts of the body. The gardens, often near water, and also in
pink-tailed skink is a secretive animal,

424 LIZARDS

Trachylepis striata Lepidothryis fernandi Tiliqua rugosa tail acts as a food-storage organ,
while the heavily armored body
African striped skink African fire skink Stump-tailed skink provides protection. Coloration is
variable, ranging from dark brown to
Length 7 – 10 in Length 9 – 141⁄2 in Length 12 – 14 in cream, sometimes with light or dark
(18 – 25 cm) (22 – 37 cm) (30 – 35 cm) spots. This slow-moving, omnivorous
Breeding Viviparous Breeding Oviparous Breeding Viviparous lizard rests under logs or in leaf litter,
Habit Mostly terrestrial Habit Terrestrial Habit Terrestrial and is an active forager. It is temporarily
Status Not evaluated Status Not evaluated Status Not evaluated monogamous: pairs remain together for
about 8 weeks in the breeding season,
Location E. and southern Location W. and C. Africa Location S. and W. then separate, often reuniting the
Africa Australia following year. Females give birth
to 1 – 3 relatively large young.

The streamlined body of the Also called the fire-sided skink, and Also known as the shingleback, this uses the same defensive technique,
African striped skink is highly formerly known as Riopa fernandi, the skink has a short, stumpy tail displaying its startlingly blue tongue to
variable in color, but is often that looks like a pinecone, ward off attack. If this fails, it may bite.
brown, with paler stripes running African fire skink has a short head and enlarged, raised This skink constantly pokes its snout
along the back. It has a pointed head, and stocky body with a brown dorsal scales. The thick about in leaf litter, actively foraging and
smooth, shiny scales, and transparent back, red and black bands scavenging for insects, mollusks, fruit,
“windows” on its lower eyelids. Males on the flanks and face, and Tiliqua gigas and leaves. It lives in colonies believed
of some populations have an orange blue and black bands on its tail. to consist of a dominant male and
head and a yellowish orange throat. Giant blue-tongued several females and juveniles. Females
This skink lives in a wide variety of It lives among leaf litter, and is active skink produce 8 – 13 young, which often
habitats, from mangrove swamps to at twilight, when it forages for insects remain close to their mother for the
arid areas, and is sometimes found and spiders. Like many other lizards, Length 20 – 24 in first few days, possibly weeks.
in high densities. Very active during this skink can shed its tail when (50 – 62 cm)
the day, it climbs into shrubs and attacked by a snake or other predator. Breeding Viviparous
trees, rocky outcrops, and The female lays up to 8 eggs in leaf Habit Terrestrial
buildings in search of prey litter or rotting wood. Since the Status Not evaluated
such as small insects and African fire skink is rarely seen in the Location S.E. Asia, New
spiders, stopping frequently to wild, most information comes from Guinea and satellite islands
bask. When attacked, it can shed its observations of captive animals.
tail. Females give birth to 3 – 9 young, A close relative of the
each about 21⁄4 – 31⁄4 in (6 – 8 cm) long, smooth, shiny scales blue and black eastern blue-tongued skink
which take 15 – 18 months to mature. bands on tail (see below), this large,
New Guinean lizard
REPTILES short, thick tail
stocky olive-green body
with thin, black crossbands

Tiliqua scincoides DEFENSIVE DISPLAY Tribolonotus gracilis

Eastern blue-tongued The eastern blue-tongued Crocodile skink
skink skink gets its name from its
large, bright blue tongue, which Length 6 – 8 in
Length 18 – 20 in it rolls out of its mouth when (15 – 20 cm)
(45 – 50 cm) threatened. Combined with Breeding Oviparous
Breeding Viviparous loud hissing, this visual display Habit Terrestrial
Habit Terrestrial is often enough to ward off an Status Least concern
Status Not evaluated attack. This skink is generally
harmless, although it has a Location New Guinea
powerful—if toothless—bite.
Location N., E., and
S.E. Australia

wide, dark bar oblique tan bars The crocodile skink has a bony,
through eyes on flank triangular head, 4 rows of spines
on the back and tail, and orange,
This large, slow-moving animal is one of short limbs glasseslike rings around its eyes. The
Australia’s most familiar reptiles. It PHYSICAL APPEARANCE glands present on the soles of its feet
lives in a wide variety of The eastern blue-tongued skink is a bulky reptile, with a wide and on the abdomen are believed to
habitats, and is often seen head, thickset body, and relatively short limbs. Light gray or brown be associated with scent secretion and
on roads, where its stubby above, it has irregular, dark brown crossbars on the body and tail. communication. It is slow-moving and
shape and camouflage 150 days. The young take about 3 years secretive, hiding in leaf litter and debris.
coloring make it look like a to reach maturity. This skink can live for If disturbed, it gives out a loud screech.
piece of fallen wood. The eastern up to 25 years in captivity. Several similar The male usually lives with one or more
blue-tongued skink has a wide-ranging species of skink live in Australia, one females, which lay one very
diet, and actively forages for snails, of them also occurring in New large egg in leaf litter
insects, carrion, flowers, fruit, and Guinea and Sumatra. or other rotting
berries; it will even scavenge for leftovers plant matter.
at picnic sites. During the breeding
season, males are territorial; mating
takes place after a brief chase, at the
end of which the male bites the female
on the back of the head. The female
gives birth to up to 25 young per litter,
following a gestation period of about

SKINKS AND RELATIVES 425

Tropidophorus grayi Ameiva ameiva Aspidoscelis uniparens ALL-FEMALE LIZARDS

Gray’s keeled Common ameiva Desert grassland
water skink whiptail lizard
Length 18 – 20 in
Length 8 – 10 in (45 – 50 cm) Length 6 – 9 in
(20 – 25 cm) Breeding Oviparous (15 – 23 cm)
Breeding Viviparous Habit Terrestrial Breeding Oviparous
Habit Semiaquatic Status Not evaluated Habit Terrestrial
Status Least concern Location Central America, Status Least concern
N. and C. South America
Location Philippines Location S. USA, This lizard reproduces by
green N. Mexico parthenogenesis, laying fertile eggs
area on without having to mate. Adults and
This slender skink has male’s back Found in deserts, grassland, and young are always female. Research
strongly keeled scales on its scrub, this is one of over a dozen suggests that this species, and
back that end in a spine, producing The common ameiva has very similar lizards that live in North others like it, evolved from single
a spiky appearance. Its tail is about the a streamlined body with a America. It has a long, slender, individuals. Each species is a
same length as the head and body. It pointed head and a very long clone—a group of genetically
lives in cool conditions, in and around tail that may be twice the length of the striped body and whiplike tail, but its identical animals.
mountain streams, often under rotting body. The male, which is more slender most remarkable feature—shared by
logs. If in danger, it may jump into the and brightly colored than the female, several other whiptails—is that it is an entirely female species: males are
water and hide under stones on the has a bright green area down the unknown. The desert grassland whiptail
streambed. Although it is a relatively center of his back. The female long tail
common skink, little is known about lays several clutches of 2 – 6 eggs lizard is a diurnal hunter that feeds
its social and reproductive behavior, throughout an extended breeding on insects. It also basks in the
except for the fact that the female gives season (March–December). Common
ameivas live in loose colonies in forest sunshine for short periods of
birth to 1 – 6 young. openings, on the edges of roads and time throughout the day. Adults
paths, and in cultivated land, usually bury 1 – 4 eggs in soil or beneath
strongly near human habitation. They bask in rocks or logs, and the newly hatched
keeled scales young have bright blue tails.
patches of sunlight, and shelter
dark brown under leaf litter or logs on STRIPED BODY light stripes on brown REPTILES
body with cool days. The desert grassland whiptail background
darker crossbands lizard is brown with 6 or 7
lighter stripes running along its pointed snout
back. Its pointed snout and slender
body taper to a very long tail, which
gives this lizard its name.

Tupinambis teguixin live in forest clearings and on Dracaena guianensis Xantusia henshawi
riverbanks, and are good swimmers.
Black tegu When confronted by predators—usually Caiman lizard Granite night lizard
large, carnivorous mammals such as
Length 32 – 43 in cats, or lizards and snakes when Length 3 – 3 1⁄2 ft Length 2 – 23⁄4 in
(80 – 110 cm) juvenile—they bite and scratch with (0.9 – 1.1 m) (5 – 7 cm)
Breeding Oviparous their claws, and also use their tails as Breeding Oviparous Breeding Viviparous
Habit Terrestrial clubs. They walk on their hind legs, Habit Semiaquatic/ Habit Terrestrial
Status Not evaluated and communicate with each other Arboreal Status Least concern
by making loud, snoring noises, Status Not evaluated
Location N. to C. South which carry a long way in still air. Location N. South Location S.W. USA
America Mating involves the male grasping the America (S. California), Mexico
female by her neck, and twisting his (Baja California)
body under hers. After mating,
One of South America’s largest the female lays 7 – 12 eggs, large, conical scales This nocturnal lizard has a flattened
terrestrial reptiles, the black tegu sometimes in burrows, but on back and tail body that enables it to squeeze under
shows some striking similarities with often at the base of a termite exfoliating rock flakes. It is covered
monitors (see p.430)—a group of lizards mound. The temperature in orange with tiny scales that are yellowish in
that are found only in Africa, Southeast the mound is kept constant throat color, with many large, black spots.
Asia, and Australasia. It has powerful by the termites, which soon
limbs and long claws for digging, and it repair the mound, sealing in the This relatively large lizard This lizard actively forages over
uses its long, forked tongue to “taste” eggs until they hatch 3 months resembles a short-headed rock surfaces at night, retreating
the air. Like most monitors, it has a later. The black tegu is occasionally crocodilian. It is greenish into narrow crevices when threatened
wide-ranging diet, including insects and eaten by humans, and its or brown, with yellow or tan by predators. Although it is not
invertebrates, birds, small mammals, skin is used in the blotches on its flanks. The particularly rare, this species is protected
other lizards, and carrion. Black tegus fashion trade. male has an orange and black because collectors destroy its habitat
by removing rock flakes to expose
glossy body powerful limbs throat, while the female’s is gray. The the lizards.
caiman lizard dives to the bottom of
thick tail shallow rivers, lakes, and streams
to find water snails, which it brings to
the surface before crushing the shells
with its large, flattened teeth, and
swallowing the soft contents. Little
is known about this rare reptile, but
it is thought to lay eggs.

426 LIZARDS

Anguimorph lizards

PHYLUM Chordata The anguimorphs include the largest Their venom enters wounds made by over long distances, using their
CLASS Reptilia of all lizards, the monitors, and the sharp fangs in the lower jaw. (Snakes’ tongue to follow scent trails left
ORDER Squamata venomous lizards, the Mexican beaded fangs are in the upper jaw.) by small mammals and birds. They
lizard and the Gila monster. This diverse also feed on the eggs of ground-
SUBORDER Lacertilia Hunting and feeding nesting birds.
group also includes the slow worm and the
Anguimorph lizards use various Reproduction
SUPERFAMILY Anguimorpha glass lizards, among others. Anguimorphs methods to find and overpower their
prey. Like most lizards, the smaller Anguimorph lizards may lay eggs
FAMILIES 9 are thought to be more evolved than other species feed mainly on insects but or give birth to live young. Several
some of the larger monitors can species of monitors incubate their
SPECIES 250 lizards, and it is likely that they were the subdue large mammals, including eggs in termite nests, using their
pigs and deer. Monitors also feed strong claws to break into the
ancestors of the snakes—many species on carrion and have an acute sense mounds. When the termites repair
the nest, the eggs are entombed in
have fanglike teeth and a long, of smell, which they use to locate a controlled environment, protected
decaying flesh. The beaded from predators. They often hatch at
forked tongue. Anguimorph lizards are lizards, too, hunt by the start of the rainy season, when the
smell, and will soil softens. Females of some species
distributed almost worldwide. track prey are thought to return to the mound to
help the young break out.
Anatomy
REPTILES HUNTING
The largest group of anguimorph
lizards are the anguids. These For such large reptiles, monitor lizards
slender lizards have smooth can be remarkably agile. The mangrove
scales, and many have small monitor (shown here) spends a large part
legs or no legs at all (as, for of its time in water but also hunts on land.
example, in the slow worm). It uses its strong claws to climb trees in
search of prey such as this tree snake.
Monitor lizards are easily
recognized by their long
neck, narrow head with a
pointed snout, powerful
limbs, and muscular tail.
They have a long, forked
tongue, which they use to test
their surroundings. This family
contains some very large
species, including the
Komodo dragon.

The venomous lizards,
the beaded lizards of North
America, are heavily built and
have a wide head with a blunt
snout, short legs, and a swollen tail.

Anguis fragilis are often brightly colored, with a Elgaria kingii long, slender body and short limbs are
metallic sheen and central stripe. adaptations for moving quickly through
Slow worm Females tend to keep the stripe as Arizona alligator grass and other dense vegetation.
adults, but males are usually a plain lizard A secretive species, it is active
Length 12 – 16 in coppery brown or gray, although some throughout the day, and sometimes
(30 – 40 cm), may have blue spots. The slow worm is
max 20 in (50 cm) a secretive animal, living in habitats that ventures out at dusk. It prefers to
Breeding Viviparous offer plenty of cover, and hiding under
Location Europe to Habit Terrestrial/ logs, flat stones, or piles of trash. It Length 71⁄2 – 12 in remain in moist areas in otherwise dry
W. Asia, N.W. Africa Burrowing may occasionally bask during the day (19 – 30 cm) woodland, and in mountains and upland
Status Not evaluated but is active mainly at dusk, when it Breeding Oviparous grassland, often near streams, where
emerges to feed on slugs and other Habit Terrestrial it forages among dead leaves and
invertebrates—a diet that makes it Status Least concern under debris for insects and spiders.
a useful visitor to gardens. Males
become fiercely territorial during the Location S.W. USA, It hibernates when food becomes scarce
breeding season and, after mating, N.W. Mexico in winter. Preyed upon by snakes, birds,
the females give birth to 6 – 12 live
young. Slow worms have a long and small mammals, it discards its tail
lifespan, but in the north of their range,
With its smooth, scaly body and up to half of it is spent in hibernation. if grasped and may smear its enemy
flickering tongue, this widespread
legless lizard looks much more like with feces. Alligator lizards live in loose
a snake than a worm. At close
quarters, it is easily distinguished from The Arizona alligator lizard has a light colonies, the males becoming territorial
snakes by eyelids that can be closed,
and—when threatened—by its ability brown body, with darker crossbars, during the breeding season. Females
to shed the end of its tail in order
to escape the grip of a and a long tail. Its scales lay 9 – 12 eggs, buried in moist sand
predator. Once shed,
the tail is very slow are shiny, and it has a fold or soil; the hatchlings
to regenerate, leaving
many adults with a of skin running along are boldly banded.
truncated appearance.
Young slow worms each flank. The lizard’s folds of
skin along
smooth scales flanks shiny scales
facilitate
burrowing dark
crossbars

short
limbs

ANGUIMORPH LIZARDS 427

Pseudopus apodus long, slender body Ophisaurus ventralis their time underground. Its tail is over
with groove along twice as long as the rest of its body,
European glass each side Eastern glass lizard and is easily shed. Active early in the
lizard morning and after rain, the eastern
tail 1.5 times Length 18 – 43 in glass lizard feeds on slugs, snails,
Length 31⁄4 – 4 ft as long as body Location S.E. USA (45 – 108 cm) insects, and small vertebrates. The
(1 – 1.2 m) of reptiles more common in Breeding Oviparous female lays 8 – 17 eggs in damp soil,
Breeding Oviparous the Americas than in Europe. Habit Terrestrial/ and guards them until they hatch.
Habit Terrestrial/ As an adult, it is uniformly Burrowing
Burrowing brown on the upperside, but Status Least concern
Status Not evaluated its young are gray with dark
Location S.E. Europe, bars. It usually lives in dry
W. Asia habitats, and it feeds on slugs,
snails, and invertebrates. If caught,
With a length exceeding that of many it may discard its tail or smear its captor This legless lizard is one of 4 closely
snakes, this legless lizard is the largest with feces. Females lay 8–10 eggs, related species found in North
member of the family Anguidae—a group and bury them in damp sand or soil. America. Brown with black flanks,
it lives mainly in damp meadows—
usually on the surface, unlike some
of its relatives, which spend most of

Anniella geronimensis Heloderma suspectum FEEDING HABITS

Baja California Gila monster The Gila monster feeds on
legless lizard small mammals and the eggs
Length 14 – 20 in of quails, doves, and reptiles.
Length 4 – 6 in Location S.W. USA, (35 – 50 cm) It hunts by smell and also
(10 – 15 cm) N. Mexico Breeding Oviparous “tastes” its surroundings
Breeding Viviparous Habit Terrestrial/ with its tongue. Venom is
Habit Burrowing Burrowing produced in glands in the
Status Endangered Status Near threatened lower jaw, not the upper jaw
as in snakes. The lizard bites
Location Mexico (Baja fiercely with its sharp teeth REPTILES
California) and holds onto its victim while
the poison enters the wound.
The Baja California legless lizard is The Gila monster is one of North The bite, although painful, is
America’s most distinctive reptiles, not fatal to adult humans.
a small, slender species with a silvery and one of only 2 dangerously swollen tail
venomous lizards in the world. Its POWERFUL BURROWER stores food
to light brown body. It does not create bulky body is marked with orange, This lizard has powerful limbs for
pink, or yellow, contrasting with bands burrowing and walks with a slow, beadlike
permanent burrows, but “swims” of black warning potential aggressors lumbering gait. Its coloration may scales
that it has a toxic bite. Gila monsters act as camouflage, or as a
through loose sand just below the live in semidesert or scrub with rocky warning to predators. strong
outcrops, in places where there is ready limbs
surface, especially around the base access to moisture. Compared to most broad head
other lizards, they are slow-moving,
of low-growing shrubs. It may come hunting by day in the spring but at dusk
or after dark during the summer heat.
above ground at night The tail stores fat in the same way as a
camel’s hump; it shrinks when food is
or at twilight, leaving hard to find, especially in cold weather
when the Gila monster hibernates.
behind trails in Females lay their eggs in late summer,
burying clutches of up to 8 in burrows
thin, dark the sand. This scooped out of damp sand.
line down little-studied lizard
back eats spiders and
small insects. If

attacked, it can shed

its tail in order to escape.

legless body aids
burrowing

Heloderma horridum the south of its range it is entirely Lanthanotus borneensis Being nocturnal and secretive, it
black. This lizard hides in burrows, is hardly ever seen. Only about 100
Mexican beaded emerging to forage for birds, especially Borneo earless lizard specimens have been collected since
lizard fledglings, as well as eggs, and small it was first described in 1878 and it
mammals. It bites and injects venom Length 16 – 18 in remains poorly known. Once believed
Length 28 – 39 in into its prey with the sharp, grooved Location S.E. Asia (40 – 45 cm) to be related to the heloderms (the Gila
(70 – 100 cm) teeth in its lower jaw. Although painful, Breeding Oviparous monster, above, and the Mexican beaded
Breeding Oviparous its bite is not often fatal to humans. Habit Burrowing/ lizard, left) and, later, the monitors
Habit Terrestrial/ Females lay 4 – 10 large, elongated Semiaquatic (see p.430), it is now thought not
Burrowing eggs in burrows. Status Not evaluated to have any living close relatives.
Status Least concern
Location W. Mexico

A close relative of the Gila monster thick, powerful This efficient swimmer inhabits
(see above), the Mexican beaded limbs for streamside burrows, which may
lizard, too, is venomous, but digging become flooded. Its short limbs
its colors are more subdued. It is often and blunt snout are adaptations for
dark brown with paler blotches, but in burrowing, while the transparent eyelids
and nostrils that can be closed by
valves are adapted for living in water.

428 LIZARDS

Varanus komodoensis dry riverbeds, where they feed ON THE SCENT OF FOOD
entirely on live animals or carrion. Komodo dragons have good eyesight,
Komodo dragon They have a keen sense of smell, but they find most of their food by
and can detect the scent of decaying smell. Like snakes, they “taste” the
Length 61⁄2 – 93⁄4 ft remains from up to 3 miles (5 km). air with their tongues, which collect
(2 – 3 m) However, they hunt mainly by scent molecules from the air. They
Breeding Oviparous ambushing prey. Young Komodo have sharp, serrated teeth, but
Habit Terrestrial dragons attack snakes, lizards, and because they cannot chew, they tear
Status Vulnerable rodents, but adults target much larger off pieces of food and then throw
prey, including wild pigs, water buffalo, them backward into their mouths.
Location Indonesia and deer. They are also cannibalistic— Komodo dragon saliva is rich in toxic
(Komodo, Rinca, Padar, one reason why juveniles spend much bacteria, and it was thought that
W. Flores) of their time in trees. when a dragon bites an animal,
these bacteria contaminate the
With an average weight of about 155 lb Adults are mainly solitary, although wound, thus weakening its prey.
(70 kg), and sometimes double this in groups may gather at the site of a kill. In 2009, it was found that Komodo
captivity, the Komodo dragon is the During the breeding season, males dragons actually produce a toxin,
world’s heaviest lizard. It has a long compete for the chance to mate, responsible for stunning the prey
body, well-developed legs, and a wrestling in an upright position with into shock and preventing its
deeply forked tongue, which it flicks their tails acting as props. After mating, blood from clotting.
out as it searches for food. Juveniles females dig nests in sandy ground,
are boldly marked, with gray or cream laying clutches of up to 25 eggs.
bands, but lose these markings as they When the eggs hatch—about 9 months
mature, becoming uniformly grayish later—the young are left to fend for
brown, with thickly folded, scaly skin. themselves. Komodo dragons take
about 5 years to become sexually
Komodo dragons live on scrubby mature, and in the wild they have a
hillsides and in open woodland and maximum lifespan of about 40 years.

REPTILES CONSERVATION

Komodo dragons are the world’s
most localized large predators,
restricted to a few Indonesian
islands. Estimated at 2,500 – 5,000,
the population is a fraction of its size
50 years ago. Its decline is due to
hunting, loss of prey, and habitat
change. However, Komodo dragons
have become increasingly important
as a tourist attraction, a practical
incentive for their conservation.

relatively small skin folds body held off A GIANT PREDATOR
head with on neck ground when Komodo dragons look ungainly, but they are capable
wide jaws walking of running at up to 11 mph (18 kph) in short bursts.
They are also good swimmers. They have a huge

capacity for food, eating up to half their own
weight in a single meal.

small scales are sharp claws used for digging long, muscular tail can be used
grayish brown burrows and unearthing food as a weapon, and as a prop
in adults when standing on hindlegs

KOMODO DRAGONS AT A KILL

12 34

FIRST ARRIVAL FEEDING BEGINS QUICK WORK FIGHTING FOR SHARES
Guided by scent, a Komodo dragon homes in on The dragon begins to feed on the deer’s body. It
a deer ambushed several hours earlier. The deer has unusually flexible joints between its jaw and The dragon feeds rapidly, swallowing flesh, skin, As more dragons arrive at the scene, the larger animals
and even bones. Meanwhile, other dragons begin try to intimidate the smaller ones into backing away
escaped, but has since died from the dragon’s bite. skull, enabling it to swallow large chunks of food. to head for the carcass as its scent drifts downwind. from the kill. If food is scarce, fighting often breaks out.

429 REPTILES

430 LIZARDS

Varanus albigularis Also known as the white-throated Varanus prasinus It feeds on insects, small vertebrates,
monitor, this lizard has powerful limbs crabs, and birds’ eggs. When
Savanna monitor for digging burrows, in which it lives; it Green tree monitor threatened, it flees through vegetation
also lives in hollow tree trunks. Territorial, and may bite if cornered. One of the
Length 31⁄4 ft (1 m), with a range of up to 7 square miles Length 30 – 39 in few monitors that are social by nature,
max 6 ft (1.8 m) (18 square km), it forages for birds, (75 – 100 cm) it appears to live in small groups made
Breeding Oviparous insects, snails, and invertebrates. Its Breeding Oviparous up of a dominant male, several females,
Habit Terrestrial/ chief predators are martial eagles and Habit Arboreal and subordinate males and juveniles.
Burrowing ratels, and it is sometimes eaten by Status Least concern Females lay clutches of up to 6 eggs
Status Not evaluated humans, despite legal protection. In in a hole in arboreal termite nests
Location E., C., and defense, the savanna monitor puffs up Location New Guinea or leaf litter.
southern Africa its throat and body, lashes out with its
tail, and bites. In a year, a female may long claws grip bark
lay 2 clutches of as many as 50 eggs.
Well equipped for its arboreal way of
crossbands life, this species has a light, slender
body that enables it to support itself on
narrow branches, and a coloration that
helps to camouflage it against the trees.

Varanus varius Varanus dumerilii Varanus flavirufus Varanus bitatawa

Lace monitor Dumeril’s monitor Sand monitor Northern Sierra Madre
forest monitor
Length 30 – 39 in
Length 5 – 61⁄2 ft Length 31⁄4 – 41⁄4 ft Location S. New Guinea, (75 – 100 cm) Length 61⁄2 ft
(1.5 – 2 m) (1 – 1.3 m) Australia Breeding Oviparous (2 m)
Breeding Oviparous Breeding Oviparous Habit Terrestrial/ Breeding Oviparous
Habit Arboreal Habit Mostly Burrowing Habit Mostly arboreal
Status Not evaluated terrestrial Status Not evaluated Status Not evaluated
Status Not evaluated
Location E. Australia Location S.E. Asia Location Philippines

REPTILES Dark gray or bluish, with white or cream indistinct light This impressive reptile has a slender, Discovered in the northern Sierra
markings, the lace monitor has a long markings powerful body that varies in color from Madre mountain forests of Luzon,
neck and tail, and long claws used for pale yellow to dark gray, but it almost in the Philippines, this spectacular
scaling trees. It bites and lashes out narrow always has a dark line extending from giant monitor was described as a
with its tail if threatened. It forages head the back of the eye to the neck. The new species in 2010. Longer than
on the ground and in trees for tail works as a prop when the monitor a tall man, it has black upper parts
insects, reptiles, birds and their Although this stands on its hind legs, but when blotched with golden spots and a
eggs, and small mammals. slender gray lizard threatened, it uses its tail as a whip black and green banded tail. The
Females lay 6 – 12 eggs in holes in is mostly terrestrial, it or club. A voracious feeder, the sand northern Sierra Madre forest monitor
termite mounds, which the termites seal; monitor eats mammals, birds, and other spends most of its life high in the
reportedly, females sometimes return to is also a good swimmer, and reptiles, as well as smaller animals and
help the young dig their way out. can close its nostrils underwater carrion. It shelters in burrows and trees, some 66 ft (20 m) above
in hollow trees, and females the ground, where it feeds almost
when in pursuit of crabs to eat. It also often lay their eggs in termite exclusively on fruit. Its secretive
forages actively for insects, birds, and mounds, clawing them open habits and reluctance to cross
bird and turtle eggs. It may occasionally to place the eggs inside.
enter the sea to escape from predators, open spaces probably explain why
mainly mammals and snakes, which it eluded detection by scientists for
threaten young lizards in particular, or so long. This species of forest monitor
may escape by climbing into trees and is separated from its closest ally in
shrubs. Males are territorial during the the southern part of the island by
breeding season; after mating, females a 93-mile (150-km) gap across a
lay their eggs in soil or leaf litter. This low-lying river valley.
monitor prefers mangrove forests but
also inhabits forests away from
the coast.

Varanus niloticus The grayish brown Nile monitor is never Shinisaurus crocodilurus the female but perhaps only in the
found far from water. It basks on nearby breeding season. To escape detection,
Nile monitor rocks or tree stumps, and feeds on Chinese crocodile the lizard may “freeze” for several hours
crabs, mollusks, fishes, and frogs, as lizard at a time, even in midstride—a tactic
well as birds, eggs, and carrion. Hunted that, along with its coloration, helps it to
Length 41⁄2 – 61⁄2 ft by crocodiles and pythons, it uses its Length 16 – 18 in merge with its surroundings. It adapts in
(1.4 – 2 m) tail, claws, and teeth to defend itself. In (40 – 46 cm) unusual ways to cool temperatures:
Breeding Oviparous the cooler part of its range, it hibernates Breeding Viviparous it may, for instance, be able to “shut
Habit Semiaquatic in communal “dens.” Females lay Habit Semiaquatic down” its system for hours to conserve
Status Not evaluated 20 – 60 eggs in termite mounds, and Status Endangered energy during very cold nights. The
the hatchlings dig their way out after female gives birth to 2 – 10 young,
Location Africa (mainly rain has softened the earth. Location E. Asia (Kwangsi
south of Sahara) Province, China) sometimes over several days.
beadlike scales
reddish brown obscure light and
neck markings dark marks

whiplike tail used for This rare, little-known lizard is olive in
swimming and defense color, with rows of enlarged, bony scales
down its back and tail, like those of a
crocodile. The male is more colorful than

AMPHISBAENIANS 431

Amphisbaenians pointed Tunneling
snout
PHYLUM Chordata Although they are sometimes called “worm lizards,” Amphisbaenians construct their
CLASS Reptilia amphisbaenians are neither worms nor lizards. They SHOVEL own burrows, down which they
ORDER Squamata are, however, closely related to lizards and belong to move in search of worms, insects,
the same order as both lizards and snakes. Adapted symmetrical and larvae. They make fresh tunnels
SUBORDER Amphisbaenia to an underground life, amphisbaenians are seen above snout by using their skulls as rams. Their
FAMILIES 6 ground only after heavy rain has flooded their tunnels. nostrils point backward, and are
SPECIES 196 Their ability to regulate body temperature is limited, KEEL thus prevented from being clogged
which confines them to tropical and subtropical regions. up with soil while burrowing. The
HEAD SHAPE lower jaw is recessed, so that,
Anatomy Amphisbaenians use their thick, as the head is forced through the
heavy skulls to dig tunnels. The soil, the mouth is held tightly closed.
Amphisbaenians are wormlike shape of the snout varies according
in appearance with cylindrical to the method of tunneling.
bodies and rings of scales that
look like body segments. They EYES AND EARS
have rudimentary eyes and
smooth heads that look wedge- An amphisbaenian’s eyes
shaped in side view. They are all are covered with translucent
without legs, except for 3 species skin, and like many burrowing
that have front limbs, positioned animals, they have poor vision.
close to the head and ending They lack external ear openings.
in long claws for burrowing.
Many amphisbaenians lack LIMBS REPTILES
pigmentation and are pinkish
brown; a few are more colorful. Amphisbaenians spend almost all their lives underground,
burrowing in soil, sand, or leaf litter. Most have lost all traces
SCALES of limbs. However, the members of one family, the Mexican
Unlike the scales of snakes, which overlap worm lizards (shown here), have retained their forelimbs.
each other, those of amphisbaenians are
arranged in concentric rings.

Amphisbaena fuliginosa conspicuous markings. It lives almost Bipes biporus Rhineura floridana
exclusively in burrows (although it may
Speckled worm lizard come to the surface at night), using Ajolote Florida worm lizard
its head to ram a tunnel through the
Length 12 – 18 in ground and its body rings to help it Length 61⁄2 – 91⁄2 in Length 10 – 14 in
(30 – 45 cm) concertina through the tunnel. It feeds (17 – 24 cm) (25 – 35 cm)
Breeding Oviparous on virtually any small vertebrates and Breeding Oviparous Breeding Oviparous
Habit Burrowing insects, attacking them with its strong Habit Burrowing Habit Burrowing
Status Not evaluated jaws. If threatened, it may shed part of Status Least concern Status Least concern
its tail, which does not regenerate. Like
Location N. South other amphisbaenians, this species is Location Mexico (Baja Location S.E. USA
America, Trinidad difficult to study since it spends most California) (Florida)
of its life underground.
This South American short tail The ajolote, or mole lizard, is one pinkish body scales arranged
species is one of white head of the world’s most remarkable resembles in rings around
the most easily reptiles. It has the typical earthworm body
recognized black and white, amphisbaenian adaptations for a
amphisbaenians cylindrical body life spent burrowing—a blunt head,
because of its cylindrical body, and short tail—but
help it burrow. Mostly found under it also has a pair of very short yet
Blanus cinereus rocks and logs, it may appear on powerful front legs. Equipped with The Florida worm lizard looks like an
the surface at night, especially after clawed feet, they help the ajolote to earthworm, with a pinkish body that
European worm lizard heavy rain. It hunts along underground excavate its way through the ground. has no limbs, no external eyes, and
tunnels for earthworms and small The ajolote rarely comes to the surface— no ear openings. Exceptional specimens
Length 4 – 8 in insects. Blanus tingitanus, found in and then only after heavy rain—and it can be up to 16 in (40 cm) long. The
(10 – 20 cm), Morocco and Algeria, used to be feeds by ambushing lizards and other scales are ill-defined and arranged in
max 12 in (30 cm) considered the same species. small animals, usually dragging them rings around the cylindrical body. This
Breeding Oviparous underground. There are 2 similar worm lizard leads its life almost entirely
Habit Burrowing species, also found only in Mexico. underground but may be forced to
Status Least concern the surface because of heavy rain or
Location S.W. Europe ploughing. An opportunistic species,
it feeds on invertebrates encountered
forelimbs short tail while burrowing. It is preyed upon
by birds—mockingbirds occasionally
The European worm lizard has a small, pink body ringed unearth it when hunting for earthworms.
pinkish or purplish brown body, with a with furrows
short head, pointed snout, rudimentary
eyes, and ringlike grooves, all of which

432 CROCODILES AND ALLIGATORS

Crocodiles and alligators

PHYLUM Chordata These large reptiles are among the Reproduction
CLASS Reptilia few survivors from the time of the
ORDER Crocodylia dinosaurs, having changed little in Male crocodilians are territorial
the last 65 million years. Collectively and mate with several females.
FAMILIES 3 Each female lays her eggs
near water, either in a mound
SPECIES 25 known as crocodilians, they include of vegetation and mud or in an
underground chamber. The
crocodiles, alligators, and caimans, females guard the eggs and
help the hatchlings out of the
and one species of gharial. Crocodilians are formidable, nest when they hear them calling.
Females stay with their young for several
semiaquatic predators. Most of them live in freshwater months (a year or more in American alligators) PARENTAL CARE
to protect them from predators.
rivers, lakes, and lagoons, while a few species inhabit In most species, the female uses
her mouth to carry her hatchlings
tidal reaches and may venture out to sea. Alligators and to a shallow pool or backwater.

caimans (with the exception of one species) are found

only in North, Central, and South America. Crocodiles HUNTING LARGE PREY

occur mainly in Asia, Africa, and Australia, with some Sometimes hunting cooperatively, large
crocodilians, such as the Nile crocodile
species in Central and South America. (shown here), are capable of overcoming
animals as large as wildebeest or buffalo.
Anatomy After the kill, the carcass may be stored
under an overhanging bank or log below
All species of crocodilians have a wide, the waterline to be eaten later.
slightly flattened body, a long, vertically
REPTILES flattened, muscular tail, powerful jaws,
and eyes and nostrils on top of the
head so that they can see and breathe
while partly submerged. A transparent
third eyelid can be closed to protect
their eyes when underwater. The
large, bony scales have raised
ridges, and are shed singly or in
pieces, unlike those of other reptiles.
Most are dull olive, gray, brown, or
black, although juveniles may have
lighter markings that disappear with
age. The 3 groups of crocodilians
differ in the shape of their snout and the
arrangement of their teeth (see below).

relatively short
snout

ALLIGATOR SNOUT Hunting and feeding
fourth lower
tooth SHAPES Crocodilians are carnivores that eat a mixture of live prey
and carrion. They use various techniques when hunting but
CROCODILE Alligators and the most common is to lie in wait at the edges of rivers and
long, narrow caimans have lakes for mammals to come within range to drink or try to
snout shorter, broader cross. Another method is to drift toward prey, such as
snouts than crocodiles. waterfowl, hoping to catch it off guard. Fish-eating species,
GHARIAL The fourth lower tooth such as the gharial, take prey with a rapid sideways swipe
flap of skin fits into a pit in the upper jaw and of their narrow jaws, which offer little resistance to the
covering windpipe is not seen when the mouth is closed. water. Birds, small
Crocodiles, however, have a notch in their mammals, and fishes
upper jaw, into which the fourth lower tooth are swallowed whole,
fits so that the tooth remains visible when but as crocodilians
the mouth is shut. The gharial has a long, cannot chew, they must
narrow snout with enlarged front teeth dismember larger prey
followed by smaller teeth of equal size. by spinning violently
about their own axis
ADAPTATIONS FOR DIVING while underwater, HUNTING BY STEALTH
holding part of the By drifting with only its eyes
Crocodilians have 2 adaptations to carcass in their jaws. and nostrils above the water,
stop water entering their lungs when a crocodilian can move to within
underwater. By closing a flap of skin striking range without being seen.
at the back of the throat, they can open
their mouth to catch prey without water STORING FOOD
passing down the windpipe. Similar flaps Having drowned this antelope,
can also be closed over the external the crocodile may eat some of
openings of the nostrils and ears. it before securing the remainder
in an underwater “larder” to rot,
making it easier to dismember.

CROCODILES AND ALLIGATORS 433

Alligator mississippiensis including birds snatched from low ALLIGATOR HOLES
branches. During the breeding season,
American alligator the males roar to attract females, and The American alligator prefers to float,
mating takes place underwater. Each partially submerged, in lakes, swamps,
Length 91⁄4 – 16 ft female lays 25 – 60 eggs in an enormous and marshes. In midsummer, as the water
(2.8 – 5 m) nest made of vegetation and mud, table falls, it retreats into “alligator holes”—
Breeding Oviparous digging it open when she hears the calls keeping a small body of water open by
Habit Aquatic of the hatching young; she may stay digging out the sand or mud at the bottom.
Status Least concern with her brood for as long as 3 years. It feeds on fishes that are trapped in the
diminishing pool and animals that visit it.
Location S.E. USA

Once widely hunted for its skin, the THE BLACK ALLIGATOR keeled scales on tail
American alligator became seriously Both adult and juvenile
endangered in the 1950s, but under American alligators are black, webbed feet for
legal protection has staged a strong but the juveniles have bold, swimming
recovery. A large, powerful reptile, it is yellow crossbands.
black with a broad head and rounded
snout, and has a heavily plated back.
It also has a characteristic large fourth
tooth that fits into a socket in the upper
jaw. This alligator feeds in or near fresh
water, taking animals of all kinds,

Caiman crocodilus Also called the common caiman, this waterbirds. Males are territorial and the same nest and guard it against
dull olive crocodilian has a bony ridge establish a dominance hierarchy.
Spectacled caiman in front of its eyes. It is found in most Females lay 14 – 40 eggs in mounds predators. Although heavily hunted for
freshwater habitats, rarely leaving the of decaying plants and soil at the
Length 61⁄2 – 8 ft water unless driven out by drought, edge of water, or on rafts of floating its skin, this crocodilian has benefited
(2 – 2.5 m) when it will burrow into the mud. It vegetation. Several females may share
Breeding Oviparous floats on the surface during the day, from artificial bodies of water, such
Habit Aquatic becoming more active at night. Adults
Status Least concern feed on other reptiles, fishes, as reservoirs, resulting in increases
amphibians, and
Location Central America, in local populations. bony
N. South America ridge
REPTILES

Crocodylus niloticus leaping up to snatch nesting birds or JAWS AND TEETH
pull drinking animals into the water.
Nile crocodile Although solitary by nature, several The Nile crocodile has long jaws,
crocodiles may congregate for feeding, with teeth that are exposed even
Length 11 ft (3.5 m), working together to herd fishes into when its mouth is closed. Like
max 20 ft (6 m) shallow water, where they are easier other crocodilians, it can bite but
Breeding Oviparous to catch. Males are territorial and it cannot chew, which presents
Habit Aquatic establish a dominance hierarchy. The problems when dealing with large
Status Least concern female lays 16 – 80 eggs in a hole dug prey such as zebras and buffaloes.
on a bank well above the water level Nile crocodiles deal with these by
Location Africa, and uses the same nest site for the dragging them underwater, and
W. Madagascar whole of her life. She guards the eggs then spinning around to tear off
throughout the incubation period. The chunks of flesh.
young chirp when they are about to
The Nile crocodile has a dark olive hatch and the female digs them out, pair of raised
to gray body with darker crossbands. gently maneuvering the hatchlings into keels down
It favors larger rivers, lakes, and her mouth, and carrying them into the tail
swamps, and is also found in estuaries water in batches. They remain together
and river mouths; it may come ashore for 6 – 8 weeks, then gradually disperse. powerful
to bask on hot days. It feeds on fishes, For the first 4 or 5 years they live in tail for
antelope, zebras, and even buffaloes, burrows up to 93⁄4 ft (3 m) long. swimming

eyes on top dark crossbands
of head on body

bony, platelike scales AQUATIC ADAPTATIONS
Like most crocodiles, the Nile crocodile
has eyes and nostrils on the top of its
head, helping it to see and breathe in
water; it also has a flat, powerful tail and
webbed hindfeet that help it to swim.

434 CROCODILES AND ALLIGATORS

Crocodylus porosus of hunting mean that such giants are now BASKING Melanosuchus niger
very rare. Equally at home in freshwater
Saltwater crocodile and seawater, these nocturnal reptiles Black caiman
feed on a wide variety of animals,
Length 16 – 23 ft including mammals, birds, and fishes. Length 13 – 20 ft
(5 – 7 m) They present a real threat to humans, (4 – 6 m)
Breeding Oviparous and have been responsible for many Breeding Oviparous
Habit Aquatic fatalities. They mate in water, and the Habit Aquatic
Status Least concern females lay about 60 eggs in mound Status Lower risk
nests on the river bank, high above the
Location S.E. Asia to watermark. Each female guards her Location N. South
N. Australia clutch, and stays with her hatchlings America
for the first few weeks of their life.
The saltwater crocodile may haul
Also known as the estuarine or WALKING ON LAND irregular itself onto a bank on hot days and Hunted for its skin, the black caiman
Indo-Pacific crocodile, this massive gray, The saltwater crocodile has strong mottling bask with its mouth agape. Having has become extinct in many parts of
brown, or black animal is the world’s enough legs to raise its body off the its mouth open stops it from its range, and its numbers are thought
largest crocodilian. The biggest ground and so can walk on land. overheating, and it allows small birds to have been reduced by 99 percent
specimens on record weighed to peck at parasites and bits of food in the past 100 years. It has an almost
over 2,200 lb (1 tonne), lodged between its teeth. parallel snout tapering sharply at the
although decades tip and gray bands on the lower jaw.
large, platelike scales It floats on the surface by day but may
broad snout come ashore to feed at night. Fishes,
pitted with 2 keels waterbirds, capybara, the occasional
deep pores on tail domestic animal, and even humans
may fall prey to it. The female lays
and guards 30 – 65 eggs, and stays
with the young after hatching.

REPTILES

Osteolaemus tetraspis Gavialis gangeticus A MULTIFUNCTIONAL SNOUT

Dwarf crocodile Gharial The gharial’s long, slender snout may
look fragile, but it is armed with small,
Length 51⁄2 ft (1.7 m), Length 13 – 23 ft extremely sharp teeth. It catches
max 61⁄4 ft (1.9 m) (4 – 7 m) fishes sideways, and then flicks them
Breeding Oviparous Breeding Oviparous within its jaws so that it can swallow
Habit Aquatic Habit Aquatic them head first. The bulbous growth
Status Vulnerable Status Critically at the end of the nose is present only
endangered in males, and is used to produce
Location W. and C. Africa Location N. Indian sounds and bubbles during courtship.
subcontinent

blunt, often bony plates Instantly recognizable by its unique LIFE IN WATER
upturned snout cover body narrow snout, the gharial—or gavial—is The highly aquatic gharial inhabits slow-moving
backwaters of large rivers, leaving the water only
a large but slender crocodilian to bask on mud or sandbanks, and to lay eggs. gray or
that spends most of its life in It submerges itself in deep water for safety. Mating, olive skin
water. Compared to other too, takes place in water. The gharial has poorly
This relatively short, black crocodile crocodilians, its legs are developed legs and is unable to walk on land,
lives in permanent pools and swamps relatively weak, and its feet barely managing to push itself over the mud.
in the African rain forest. It hides in are broadly webbed. Gharials bulbous
burrows and among submerged tree feed primarily on fishes, growth
roots during the day, and forages at although they also eat waterbirds.
the water’s edge at night, taking its During the breeding season, the male
prey with a sideways snap of the jaws. becomes strongly territorial, and
In areas with seasonal flooding, fishes assembles a harem of females. The
are the main food in the wet season, female excavates a nest well away
and crustaceans for the rest of the from the water’s edge, and lays up to
year. Frogs and toads are also eaten. 50 eggs, which at about 5 oz (150 g)
The female lays usually 10 eggs in a each are unusually large. She protects
mound of soil and vegetation, guards the hatchlings, but does not carry
them, and protects her young in the them to water—probably because of
water. This crocodile is probably the unsuitable shape of her jaws. The
common in some parts of its range, gharial almost became extinct in
but in others, its numbers are depleted the 1970s as a result of habitat loss,
because of habitat destruction. hunting, and fishing; subsequent captive
breeding has only had limited success.

435REPTILES

EXHALING UNDERWATER
Crocodiles breathe air just as mammals
do. This saltwater crocodile will soon have
to return to the surface to take in more air.



AMPHIBIANS

438 AMPHIBIANS

amphibians

PHYLUM Chordata Amphibians are intimately associated with water,
CLASS Amphibia most of them spending part of their life in water and

ORDERS 3 part on land. These ectothermic (cold-blooded)

FAMILIES 75 vertebrates are divided into 3 groups: newts
SPECIES 7,615 and salamanders; frogs and toads; and the

wormlike caecilians. The life cycle of most amphibians

involves a transformation from aquatic larvae (which

breathe using gills) to terrestrial adults (which take in TREE FROG
This tree frog,
oxygen through lungs). Most live close to water from the rain forests of
New Guinea and northern
in tropical and temperate regions, although some Australia, has moist skin that is
well suited to its wet and humid habitat.
have adapted to survive cold and drought.

AMPHIBIANS Past and present their fish ancestors. These enabled have become extinct. The reasons Anatomy
them to lift their bodies off the ground, for this are complex, and not fully
The first amphibians, which appeared although they were still heavily built understood, but they probably involve Compared to other vertebrates,
about 370 million years ago during the animals, with slow and clumsy a range of factors, acting both on a amphibians have a fairly simple
Devonian Period, were descendants movements compared to amphibians local and global scale. Among them body structure, well adapted for
of fleshy-finned fish. They were the alive today. By about 280 million are contamination by waterborne life in water and on land. Most adult
first vertebrates to colonize the land, years ago, amphibians had become pollutants, infection by chytrid fungi, amphibians have 4 limbs, with 4
and had scaly skin and a finned tail, the dominant land animals. However, and climate change. Chytrid disease digits on the front limbs and 5 on the
but also lungs that could breathe over the next 70 million years, was first observed in Australia, but it back. Newts and salamanders have
now affects amphibians on several a relatively small head, a long, slender
air. They were also the first amphibians were superseded continents, and may eventually body, with short limbs of equal length,
quadrupeds, evolving 2 pairs of by terrestrial reptiles (which spread worldwide.
jointed limbs from the fins of had evolved the ability to lay and a long tail.
shell-covered eggs on land) SKELETON orbit However, some
AMPHIBIAN ANCESTOR and most species gradually This skeleton of a juvenile
Diplocaulus lived about died out. Japanese giant salamander salamanders have
280 million years ago highlights an evolutionary trend brain
and probably resembled Much more recently, toward simplifying the amphibian case
a modern newt, but amphibians have been struck skeleton. It contains fewer bones
for an unusually by a far more rapid decline. than other vertebrates, humerus
shaped head. Many living species are and far fewer than its
endangered—nearly 500 fish ancestors.
critically so—and in the
last 2 decades, a number

SKIN short
ribs
The skin of an amphibian is naked and smooth, with no scales carbon dioxide expelled oxygen absorbed
from bloodstream into bloodstream thoracic
or hair to protect it. It is permeable to water and, although poison vertebra
mucous gland connective
numerous mucous glands help to keep the skin moist, most gland tissue femur caudal
vertebra
amphibians quickly dry out if they are not in a damp place. All epidermis knee
joint
amphibians have poison glands in their skin, and many produce

secretions that are distasteful or highly toxic to potential predators.

The skin usually contains numerous pigment cells, and many

amphibians are brightly colored. This is especially common in

poisonous species, in which striking skin patterns serve as a

warning. Many amphibians use their skin for breathing, which dermis

means that it has to be kept moist

at all times. This may also place

a limit on how large amphibians

can be, since they need to very small limbs with reduced
numbers of digits, or lack rear
maintain a high ratio of surface limbs entirely. Most frogs and
toads have a distinctive compact
area to volume, to absorb an blood vessel carrying blood vessel carrying body shape, with a large head,
oxygenated blood deoxygenated blood short back, small front limbs, large,
adequate amount of oxygen. muscular back limbs, and no tail.
IN SUNLIGHT Caecilians have a wormlike, limbless
BREATHING THROUGH THE SKIN body, with a pointed head and a short
IN SHADE CHANGING SKIN COLOR tail. Other than caecilians, which use
Many amphibians can breathe through their skin, smell, most amphibians hunt using
The base color of some amphibians’ absorbing oxygen directly into their bloodstream and sight and have large eyes that help
skin changes in response to variations in expelling carbon dioxide. In addition to being packed with them to locate prey at night. They
temperature, light level, or mood. When blood vessels—some only a few cells’ width from the
in sunlight, the skin of the Australian green surface—the skin is very thin, enabling the easy transfer
tree frog (left) is light green but on entering of gases. Mucous glands keep the surface damp, helping
shade gradually turns brown. the gases to pass through.

AMPHIBIANS 439

WORMLIKE AMPHIBIANS water at the same moment as the TAKING TO LAND than the adult stage. Nearly all AMPHIBIANS
With their long bodies, body rings, and lack female expels her eggs. In most newts Swarms of newly metamorphosed European amphibians actually become smaller
of limbs, caecilians are often mistaken for large and salamanders, fertilization is common frogs gather by the side of a pond during metamorphosis.
earthworms. Most are found in loose soil or internal, the sperm being transferred before leaving the water for the first time.
deep leaf litter in tropical forests. to the female in small, gelatinous Some amphibians show direct
capsules called spermatophores. enormously: some amphibians lay development, in which the larva is
also have an extremely wide mouth, This requires precise coordination only one or 2 eggs at a time; others not free-swimming but completes its
which enables them to consume between the movements of male lay up to 50,000. The eggs hatch into development while still inside the egg
relatively large prey. and female, and many newts and minute larvae, which retain sufficient and emerges as a tiny version of the
salamanders have elaborate yolk to sustain them for a few days. adult form. Direct development occurs
Although most adult amphibians courtship behavior to achieve in a number of species that lay their
breathe using lungs, they do not this. In caecilians, the male The larvae of amphibians (called eggs on land, and also in some that
have a rib cage and a diaphragm has a penislike organ, tadpoles in frogs and toads) are very retain their eggs inside the body. Such
to inflate them. Many amphibians which he uses to insert different in appearance, diet, and species, by having no free-swimming
can absorb oxygen into their blood his sperm directly lifestyle from adults. Metamorphosis larval stage, are not dependent on
through other organs and tissues, into the female. involves a major reconstruction of all standing water.
including gills, the skin, and the lining parts of the body (see panel, below).
of the mouth. The relative importance The eggs of amphibians The larvae of newts and salamanders Breeding migrations
of each route varies among different have no shell, but are are carnivorous, feeding on tiny
life stages and adult forms. Young enclosed in a gelatinous invertebrates. In contrast, the Most amphibians live on land as adults
amphibian larvae breathe using envelope that quickly shrivels tadpoles of frogs and toads are but return to water each year to breed.
external gills, as do those up in dry conditions. Eggs may typically herbivores, either filter Breeding is usually stimulated by a
salamanders that retain the larval be laid singly, in strings, or in clumps; feeding on microscopic plants that combination of environmental factors,
form into the adult stage. Most they may be carefully attached to live suspended in water, or grazing including temperature, rainfall, and
terrestrial frogs and toads, and some plants or other solid objects, or just on algae that cover plants, rocks, day length. In some species, referred
salamanders, have lungs, but also left to drift in the water. Several and other submerged objects. to as explosive breeders, there is a
absorb a certain amount of oxygen amphibians show parental care, mass migration of adults, all moving
through the skin and the mouth guarding their eggs against predators The larval stage is an important toward a breeding pond. Evidence
(see panel, opposite). One group and infection from fungal diseases. growth phase for amphibians, but shows that various species locate
of salamanders, the plethodontids, The number of eggs laid varies different species vary considerably in the same breeding site year after
have no lungs and rely entirely the amount of total lifetime growth year by using their sense of smell,
on the skin and the mouth to PARENTAL CARE that is completed in the larval rather an ability to navigate by the sun, or
take in oxygen. European newts lay their eggs individually. by detecting tiny variations in the
Wrapping them in leaves may protect them earth’s magnetic field.
Life cycles from UV radiation.

An amphibian’s life cycle involves GROWTH AND DEVELOPMENT
3 stages—egg, larva, and adult, with
the transition from larva to adult The 3 stages of amphibian development are clearly
involving a radical transformation
known as metamorphosis. illustrated by the European common frog. Embryos

Most amphibians deposit their eggs start to develop inside the eggs, which are laid in
in water. However, some species lay
their eggs on land, and others show clumps. About 6 days after fertilization, the eggs hatch
a variety of ways of retaining them
inside their body. In nearly all frogs into tiny tadpoles with a spherical body, well-developed
and toads, fertilization is external,
with sperm entering the eggs outside tail, and external gills. Within 4 weeks, these gills have FROG SPAWN
the female’s body. During mating, the
male clasps the female, usually from been absorbed and replaced by internal gills. Between RECENTLY HATCHED
above, and sheds sperm into the 4 WEEKS OLD
6 and 9 weeks, the back limbs start to develop, the

head becomes more distinct, and the body takes

on a more streamlined shape. At this stage, the external
legs are fully functional and the internal gills gills

have been replaced by lungs. By 9 weeks,

when the front legs have emerged, the

tadpole has the compact body shape of an

adult. The tail is then gradually absorbed internal
into the body, until, by about 16 weeks, gills

it has disappeared entirely.

EGG TO ADULT nearly adult back limbs 6–9 WEEKS OLD
body shape appear long tail remains
The European
common frog’s shrinking
development, from egg tail
to adult, typically takes
KEEPING GUARD about 16 weeks, but 12 WEEKS OLD front limbs appear MIGRATING FROGS
varies according to 9 WEEKS OLD
This marbled salamander guards its clutch of temperature levels Some species of amphibians, such as these
eggs at the edge of a pond. The female curls and food supply. European common frogs, make annual mass
her body around her eggs to protect them from migrations to breeding sites, often from great
predators and fungal infection. distances and across rough terrain.

440 NEWTS AND SALAMANDERS

Newts and salamanders

PHYLUM Chordata Newts and salamanders have a Feeding
CLASS Amphibia slender body with a long tail and,
ORDER Caudata typically, 4 legs of similar size. All newts and salamanders are
carnivorous and feed on living prey.
FAMILIES 9 Of the 3 main groups of living They find their prey using a combination
of smell and vision; in addition, some
SPECIES 707 amphibians, they most closely aquatic species are very sensitive to
water currents made by moving
resemble the animals from which animals. Since they are rarely very
active, newts and salamanders do
all amphibians are descended. They also have not have a high energy requirement
and do not need to feed very often,
some of the most complex and varied life histories. especially if they have eaten a large
amount. When food is abundant, they
Some salamanders live their entire lives in water, accumulate fat deposits that enable
them to survive periods when it is too
while others are wholly terrestrial. Newts spend most SALAMANDER HUNTING dry or too cold for them to feed. The
larvae are also carnivorous, eating a
of their lives on land but return to water to breed— Salamanders have wider mouths than newts and can wide variety of aquatic invertebrates.
catch larger prey like this earthworm. Many have a long In some species, faster-growing larvae
other than this, there is no scientific distinction tongue that flicks out then opens up to engulf the prey. become cannibalistic, eating smaller
larvae of their own species.
between salamanders and newts. In all but the most

primitive species, fertilization is internal (rather than

external, as in most frogs and toads). The male does

not have a penis but instead passes capsules of

sperm to the female during mating. The larvae of

newts and salamanders are carnivorous, and have

a long, slender body, a deep, finlike tail, and large,

AMPHIBIANS feathery external gills. Newts and salamanders

are found in damp places and are largely

confined to the Northern Hemisphere.

Anatomy

Newts and salamanders differ from frogs and toads
in that they retain their tail into adulthood. They also
have a relatively small head and small eyes, smell being
the most important sense for finding food and social
interaction. Most newts and salamanders have 4 legs
(with 4 digits on the front limbs and 5 on the back), although
some aquatic salamanders have no hind legs and only
small front legs. Many salamanders have distinct moisture-
maintaining “costal” grooves that run around the body.
Newts and salamanders vary in the way that they
take in oxygen. Some are able to breathe through their
smooth, moist skin, while many of those species that
spend all their life in water retain the large, feathery
external gills characteristic of the larval stage.

LUNGLESS

SALAMANDERS
The plethodontids are
a group of typically wholly
terrestrial salamanders. They
have no lungs but instead
breathe through their skin and
their mouth and throat, which
have a rich blood supply.

SIRENS COURTSHIP

The sirens, of which there are 4 species, spend The courtship of newts and salamanders is varied and often elaborate. Courtship
their entire lives in water. In addition to having precedes and accompanies the transfer of sperm from male to female in capsules
lungs, like some other aquatic salamanders, they known as spermatophores. The male stimulates the female by secreting
take in oxygen through large, feathery external gills compounds known as pheromones. These are usually delivered via the nose but
on the side of their head. In periods of drought, in some species they are passed directly through the skin. European newts—such
they can survive for several weeks or months, as these Alpine newts (here the male is on the left)—use visual displays rather
encased deep inside a cocoon of dried mud. During than contact to stimulate the female, but in many salamanders the male holds
this time, they feed on their large fat reserves. the female in a mating embrace known as amplexus while he stimulates her.

NEWTS AND SALAMANDERS 441

Life cycles LAND LAND

Newts and salamanders have complex life cycles, adult
which typically involve 3 distinct stages: the egg,
larva, and adult. The female lays eggs that contain eft adult adult
yolk to support the growth of the developing embryo. larva eggs larva eggs
Some species lay many small eggs, others a few
large eggs, each containing a lot of yolk. The eggs juvenile
hatch into larvae that have feathery external gills
and feed on small animals. The larvae grow until courting larva
they reach the stage at which they undergo adults developing
metamorphosis into the adult form; this involves inside egg
the loss of the gills and a switch to breathing air egg
via the lungs and skin. The juvenile stage, which in
some is known as the eft stage, is spent on land WATER WATER
and may last for several years. In the adult stage,
individuals become sexually mature and start to AMPHIBIOUS TERRESTRIAL AQUATIC
breed; this may involve a brief return to water.
There are many variations on this basic pattern, This life cycle is typical of American, The eggs of terrestrial salamanders are In the aquatic life cycle, all the life stages
which usually coincide with whether the species are completed in water. The female typically
is amphibious, terrestrial, or aquatic (see right). European, and Asian newts. Adults typically laid on land. There are usually produces a large number of small eggs
and does not care for them. The adults
spend most of their life on land but relatively few, large eggs, each containing become sexually mature while retaining
many of the anatomical and physiological
return to water each spring to breed. a lot of yolk, which may be protected by features of the larval stage. In many
species, there are individual populations
This involves a partial reversal of the mother. The larval stage is completed that have an aquatic life history, while
others have an amphibious one.
metamorphosis, as individuals develop within the egg, which hatches to produce

skin that can absorb oxygen from a miniature terrestrial adult. In some

water and a tail like that of the larva, species, the eggs may be retained inside

enabling aquatic newts to the female’s body. She gives birth, either

swim powerfully. to aquatic larvae or to terrestrial juveniles.

external gills fin extends from back
along length of tail

NEOTENIC NEWTS AND SALAMANDERS AMPHIBIANS

In neotenic newts and salamanders, individuals
become sexually mature while still in the
larval stage. They are fully aquatic and
have large, feathery external gills.
The best known example is the
axolotl (shown here), which
can be artificially made to
metamorphose into a
terrestrial adult form by
injecting it with the
hormone thyroxin.

Defense UNKEN POSITION COLORATION

For most newts and salamanders, the risk of being attacked Some species of newts Many newts and salamanders have skin patterns and colors
by a predator is greatly reduced by being active only at night. and salamanders that provide camouflage. Others are very brightly colored,
Many species also produce distasteful or toxic secretions adopt bizarre defensive usually indicating their capacity to produce noxious or toxic
from glands in their skin. These glands may be concentrated positions. This Italian skin secretions. However, in some species (such as this
on the head or the tail. The skin secretions of Californian newts spectacled salamander alpine newt), males become more brightly colored to
are particularly lethal. Such species are often has taken the contorted attract females during the breeding season.
brightly colored to warn predators, “unken” position to alarm
although the effectiveness of this predators and expose its
coloration depends on predators bright warning coloration.
learning to associate it with
unpleasant consequences. A few
species do not produce noxious
secretions but mimic the color
patterns of those that do. Several
species are able to shed their tails
when attacked. The detached tail,
which twitches after it is dropped,
distracts the attention of a predator
away from the animal’s body.

442 NEWTS AND SALAMANDERS

Siren lacertina and this color provides it with Cryptobranchus alleganiensis Andrias japonicus
good camouflage in the muddy water
Greater siren of ponds, lakes, and slow-flowing Hellbender Japanese giant
rivers. This siren spends the day salamander
Length 20 – 35 in resting on the bottom, but at night Length 12 – 29 in
Location E. and S.E. USA (50 – 90 cm) forages for food, either crawling over Location E. USA (30 – 74 cm) Length Up to 41⁄2 ft
Habit Wholly aquatic mud or sediment, or swimming with Habit Wholly aquatic (1.4 m)
Breeding Early spring a sinuous movement of its tail. Like Breeding Fall Habit Wholly aquatic
season most amphibians, greater sirens are season Breeding Late summer
Status Least concern almost entirely carnivorous—snails, Status Near threatened season
insect larvae, and small fish making Status Near threatened
up most of their food. However, during Location Japan
droughts, they encase themselves
Sirens are among the largest amphibians in mud cocoons, and can survive Along with the Chinese giant
in North America. There are 2 species, without food for up to 2 years. Greater salamander (Andrias davidianus),
both with long, eel-like bodies and sirens lay their eggs in early spring. the Japanese giant salamander is the
only one pair of legs, behind their When their larvae hatch, they are largest amphibian in the world. It is
feathery external gills. The greater little bigger than most other gray or brown, with a flattened body,
siren is usually gray or olive-brown, amphibian tadpoles. small eyes, and sprawling legs. Its
head and throat are warty, and the skin
feathery external gills along its sides is deeply folded—a
characteristic that helps it to absorb
AMPHIBIANS The hellbender is the only North oxygen from the surrounding water.
American member of the giant It is active mainly at night, feeding
salamander family—a group of 3 on fish, worms, and crustaceans.
species notable for their wrinkled skin During the breeding season, the male
and exceptional size. Green, brown, digs a spawning pit, in which the
or gray, often with darker spots, it has female deposits strings of about 500
a head flattened like a spade, small eggs. The male then guards the eggs,
eyes, and a long, paddlelike tail. It aggressively fending off predators.
is nocturnal, and uses its head to Japanese giant salamanders can
dig out crayfish and other prey. The live for over 50 years, but they are
hellbender has a strong bite, and its a traditional delicacy, and have
skin secretes a noxious slime. Females become increasingly rare.
lay their eggs in fall, and the
males guard them until they hatch. ADAPTABLE GILLS

Pseudobranchus striatus external gills Necturus maculosus small front
help it breathe in legs
Northern dwarf water with a low oxygen content. This Mudpuppy
siren nocturnal amphibian inhabits swamps,
ditches, and marshes, and estivates in
Length 4 – 9 in mud during the dry season. It feeds on Length 113⁄4 – 191⁄2 in red external
(10 – 22 cm) aquatic invertebrates, and is preyed (29 – 49 cm) gills
Habit Wholly aquatic upon by wading birds, water snakes, Habit Wholly aquatic
Breeding Not known alligators, and turtles. The female Breeding Fall in north,
season attaches her eggs to water plants. season winter in south
Status Least concern Status Least concern
Location S.E. USA Location S. Canada,
C. and E. USA

This small, eel-like siren is brown or The mudpuppy has a long, cylindrical The gills of the mudpuppy adapt to
black above, with one or more yellow body, a flattened tail, feathery external the oxygen content of the animal’s
or tan stripes along its body. Its gills, and 2 pairs of limbs, each with habitat. In cool, oxygen-rich water
forelimbs are small, each with 3 toes, 4-toed feet. It is brown, gray, or black, they are usually small, but in
and it has no hind limbs. The feathery usually with black spots and blotches. stagnant, warm water they tend
An inhabitant of freshwater habitats, it to be considerably larger.
Batrachuperus pinchonii about 12 costal grooves along its flanks. feeds on small animals, mainly at night.
Females lay their eggs in early summer until they hatch, about 2 months later.
Western Chinese It has short legs, with 4 toes on each under rocks and logs, then guard them The mudpuppy has disappeared from
mountain salamander many polluted or silted rivers.
limb, and a short tail that is flattened

from side to side. This nocturnal animal

lives in cold, clear, fast-flowing streams BODY SHAPE
The flattened, eel-like body shape
at high altitudes. Since there are few of the mudpuppy enables it to dark blotches
burrow under rocks and logs.
Length 5 – 6 in fish in these cold water courses, the
(13 – 15 cm)
Habit Largely aquatic eggs and larvae of this salamander slimy skin
Breeding Spring and
season summer are relatively safe from predators. The
Status Vulnerable
female lays 7 – 12 eggs in hollows under

Location E. Tibet, China rocks in the streams. glossy, brown or
(Sichuan Province) stocky body green coloration

This robust amphibian
has a pale brown or
olive-green body, usually
with darker spots, and

NEWTS AND SALAMANDERS 443

Proteus anguinus with 3 toes, and the rear pair with Salamandra salamandra FEEDING HABITS
only 2. It also has red feathery external
Olm gills, which it retains throughout its Fire salamander
life. Olms inhabit streams in caves,
Length 8 – 12 in sometimes several miles from Length 7 – 11 in
(20 – 30 cm) a cave opening, and feed on (18 – 28 cm)
Habit Wholly aquatic small invertebrates. Habit Wholly terrestrial
Breeding Not known Breeding Spring, summer,
Location S. Europe season Location Europe season after heavy rain
Status Vulnerable Status Least concern

The olm is one of the few amphibians Similar in appearance to the tiger The fire salamander is active mainly
that has become adapted to life in salamander (see p.444), this robust at night, especially after rain, when
caves. It has a long and very slender amphibian has an eye-catching it emerges from beneath logs and
body, a pinkish skin almost devoid coloration that warns predators that it is stones to feed on worms, slugs,
of pigment, rudimentary eyes, and poisonous. It produces a toxic secretion insects, and insect larvae.
2 pairs of tiny limbs—the front pair from glands behind its eyes, and this is
distasteful to anything attempting to eat inside the female until the larval stage,
Chioglossa lusitanica it. The fire salamander inhabits forests and are then released into ponds or
and woodland on hills and mountains; streams. During their development
Golden-striped it spends the winter underground. in the oviduct, larvae are occasionally
salamander Breeding involves the male grasping cannibalistic, eating their smaller
his mate from below and depositing a siblings as eggs or larvae. In some
Location S.W. Europe Length 43⁄4 – 51⁄2 in spermatophore; he then flips to one side high-altitude populations, the young AMPHIBIANS
(12 – 14 cm) so that she falls on it. The eggs develop develop to the adult form inside the
Habit Mostly mother’s body.
terrestrial short tail
Breeding Early spring poison
season BODY COLOR glands
Status Vulnerable The body color is variable, depending on head
on geographical location. It can be black
The slender body and long tail enable the has large eyes and a long, sticky tongue and yellow, or yellow with black spots prominent
golden-striped salamander to run very for catching insects. If attacked, it may or stripes. In some areas, the yellow eyes
fast, like a lizard. Its coloration is dark shed its tail. During the breeding season, may be replaced by orange or red.
brown, with 2 yellow, copper, or golden swellings appear on the upper front
stripes on its back that merge to form a legs of males. After mating, females
single stripe on the tail. This salamander lay their 15 – 20 eggs under rocks in
well-oxygenated but often slightly
acidic streams.

Tylototriton verrucosus Triturus cristatus the breeding season, the male Ichthyosaura alpestris
develops a large, jagged crest on its
Crocodile newt Great crested newt back, and a white or blue streak along Alpine newt
the tail. Like many other newts, the
Location S. and S.E. Asia Length 51⁄2 – 7 in Location Europe, C. Asia Length 4 – 51⁄2 in male courts the female with a complex Location Europe Length 21⁄4 – 43⁄4 in
(14 – 18 cm) (10 – 14 cm) underwater dance, and concludes the (6 – 12 cm)
Habit Mostly terrestrial Habit Mostly terrestrial display by transferring a spermatophore Habit Mostly terrestrial
Breeding Monsoon Breeding Spring and to the female. The female lays her eggs Breeding Spring
season season summer singly and wraps them in leaves, season
Status Least concern Status Least concern probably for protection. These newts Status Least concern
are widespread throughout Europe, but
Also known as the mandarin salamander, Also known as the warty newt, this in many areas their numbers have The alpine newt has a small body,
this robust newt has a large head and secretive animal lives mostly on land decreased because their breeding blue above and bright orange below,
thickset body, with rough black skin. The but spends about 3 – 5 months of the habitat has been drained. and a short tail. In the breeding season,
prominent orange warts, ridges, and year in ponds, lakes, and ditches.
glands indicate that the crocodile newt It is dark brown above, with a crest on male the male develops a low, black
will exude distasteful skin secretions characteristically warty skin, and bright and white crest along his back,
if attacked. This newt lives most of its orange with black spots below. During black and white spots on his
life on land—spending winter and dry sides and tail, and a swollen
periods underground—but during the cloaca. As with most newts, the male
monsoon it migrates to breeding ponds, attracts the female by fanning his tail
where it attaches its eggs to water and wafting a pheromone toward her
plants. Active at night, the crocodile snout. In the Balkans, some of these
newt feeds on invertebrates. nocturnal animals are permanently
aquatic, retaining larval features, such
prominent as external gills, into adulthood.
ridge

rough, warty skin

444 NEWTS AND SALAMANDERS

Taricha torosa body is brown or brick-red above, Notophthalmus viridescens
and yellow to orange below. During
California newt the breeding season, when these newts Eastern newt
carry out mass migrations to ponds and
Location W. USA Length 5 – 8 in streams, the males develop a smooth, Location E. Canada, Length 21⁄2 – 41⁄2 in
(California) (12.5 – 20 cm) slimy skin, black patches on their feet, E. USA (6.5 – 11.5 cm)
Habit Mostly terrestrial and a swollen vent (cloaca). The Habit Largely terrestrial
Breeding Winter and California newt is protected by a toxic Breeding Variable
season spring secretion that makes both its skin and season
Status Least concern flesh extremely poisonous. It is nocturnal Status Least concern
and feeds on invertebrates of all kinds.
California is particularly rich This common North American newt JUVENILE COLORATION
in salamanders and newts, warty skin has a complex life cycle. It breeds The young eastern newt, or the red eft, is
and this species is one in freshwater habitats, but instead of bright red, orange, or brown all over, with
of over 20 that live in the long tail developing directly into adults, its larvae black-edged red spots along its back, and
state. Its rough, warty turn into specialized juvenile forms, rough skin. This terrestrial juvenile stage lasts
called red efts. Red efts live on land— for 1 – 4 years, after which the red eft returns
Pleurodeles waltl amphibians. Like usually in grassland, mountain forests, to water to develop into an adult.
most salamanders, it is and other damp habitats—and then ADULT STAGE
Sharp-ribbed protected by toxic skin secretions, but it return to water after 1 – 4 years, where This newt completes its development in
salamander also has sharply pointed ribs that project they reach maturity. Outside the water. Its upperside turns greenish yellow,
through its skin when it is held. Together breeding season, adults live on land. with black-edged red spots, and its underside
with its chemical defenses, these help During the adult and eft stages, these becomes yellow. The breeding male has a very
deter most predators. Sharp-ribbed newts are protected from predators deep tail, a swollen cloaca, and rough pads on
salamanders are mainly nocturnal and by highly toxic skin secretions. the inside of its thighs.
spend their lives in water, except in times
AMPHIBIANS Location S.W. Europe, Length 6 – 12 in of drought, when they survive by hiding
N.W. Africa (15 – 30 cm) in mud until wetter conditions return.
Habit Wholly aquatic During the breeding season, females
Breeding Any time, except lay 200 – 300 eggs singly or in clumps,
season cold weather fastening them to water plants.
Status Near threatened

plump body warts long, flattened
on body tail

This mottled gray-green
salamander is one of
Europe’s largest tailed

Amphiuma tridactylum Dicamptodon tenebrosus Ambystoma tigrinum mainly on invertebrates, although some
individuals may become cannibalistic,
Three-toed Pacific giant Tiger salamander growing larger mouths with extra teeth.
amphiuma salamander In most areas, the young leave the water
Length 7 – 14 in once they have developed adult bodies,
Length 18 – 43 in Length 61⁄2 – 131⁄2 in Location North America (18 – 35 cm) but in some regions—particularly in the
(46 – 110 cm) (17 – 34 cm) Habit Mostly terrestrial west—they may retain their larval form
Habit Wholly aquatic Habit Mostly terrestrial Breeding Variable, permanently, reproducing without taking
Breeding Winter and Breeding Spring and season after heavy rain up life on land. The chief predators of the
season spring season fall Status Least concern tiger salamander are fish, which eat
Status Least concern Status Least concern the larvae; however, in recent years, the
Location C. and S. USA Location S.W. Canada, species has suffered through pollution
N.W. USA and habitat loss.

The stout-bodied tiger salamander is small eyes rounded
one of North America’s most colorful snout
amphibians, and is also one of the most
Active at night, this dark brown to black locally varied. At least 6 subspecies are large head
salamander, with light brown mottling, known: the eastern subspecies have a
This large, slimy salamander has a lives in wooded habitats in and around dappled pattern of black and yellow yellow
slender, eel-like body that is black, streams. It passes through an aquatic markings, but those farther west— blotches on
gray, or brown above, and pale gray larval stage lasting for several years. including the one shown here—have black body
below. The tail is flattened from side When individuals reach maturity, they larger yellow blotches or vertical bars.
to side, and each of the tiny limbs may become terrestrial. However, some Adult tiger salamanders generally live
has 3 toes. It inhabits ditches, never leave the water, becoming aquatic on land, and hibernate in burrows dug
swamps, streams, and ponds adults. Those that do leave the water by other animals. In early spring, once
and, in periods of drought, it can are the world’s largest terrestrial any ice has melted, they migrate to
survive buried in mud. Active salamanders. In defense, this animal ponds, lakes, pools, and reservoirs to
at night, it feeds on worms secretes noxious mucus from its tail. breed, sometimes in large numbers. The
and crayfish. This animal Populations have been adversely females lay up to 7,000 eggs in a single
can deliver a painful bite. affected by the silting of streams. breeding season, and their larvae feed

12 or 13 costal grooves cylindrical tail

NEWTS AND SALAMANDERS 445

Ambystoma mexicanum CAPTIVE FORMS Ambystoma macrodactylum Plethodon jordani

Axolotl Long-toed Jordan’s salamander
salamander
Length 4 – 8 in Length 31⁄4 – 71⁄2 in
Location Mexico (Lake (10 – 20 cm) Length 4 – 61⁄2 in Location E. USA (Southern (8.5 – 18.5 cm)
Xochimilco) Habit Wholly aquatic (10 – 17 cm) Appalachian Mountains) Habit Wholly terrestrial
Breeding Summer Habit Mostly terrestrial Breeding Summer
season Breeding Fall and season and fall
Status Critically season spring Status Near threatened
endangered Status Least concern

Typically black in the wild, many Location S.W. Canada,
color variants of the axolotl have N.W. USA
been bred in captivity. They may
This plump amphibian is a classic be albinos (white with red gills), The long-toed salamander is found Also known as the red-cheeked
example of neoteny, or the ability to gray, or mottled black and white. salamander, this nocturnal species has
breed without ever developing a fully This species is more commonly in a wide variety of terrestrial habitats, a long, slender body and tail, a large
adult body. It has a flattened tail and seen in captivity than in the wild. head with prominent eyes and, typically,
large external gills—features that most If the captive animals are injected where it spends much of its time red patches on its legs or cheeks,
salamanders lose when they become with a thyroid hormone, they lose although this characteristic varies
mature and take up life on land. Largely their gills and become terrestrial. underground. However, in spring, considerably between subspecies.
nocturnal, the axolotl feeds mainly on Both males and females are territorial.
invertebrates, and is preyed upon in large numbers of this nocturnal If threatened, this salamander produces
turn by waterbirds. Axolotls are critically a distasteful slimy secretion from its
endangered as they live in a single species migrate to ponds to breed. It tail, and may shed its tail if attacked.
lake, in an area that has seen rapid It mainly feeds on millipedes, beetles,
urbanization in recent years. Once has a slender gray or black body, with and insect larvae. The male breeds
esteemed as a delicacy, they are every year, while the female breeds
now legally protected. rounded a yellow, tan, or green dorsal stripe or only in alternate years.
snout
red external gills blotches on the body. When attacked,

it coils its body and lifts its tail in the

air. Numbers have reduced because

of habitat loss and the introduction

of fish, that eat the larvae, to its

breeding areas. white speckles
on flanks
ALBINO
One color variant of the smooth, AMPHIBIANS
axolotl is the albino. white body
This has a smooth,
white body and
red gills.

Plethodon glutinosus slime is extremely sticky—taking several Desmognathus ochrophaeus mottled dark gray, with legs that
days to wash off—and it gives the vary from brown to red (pictured
Slimy salamander highly effective protection Mountain dusky below is a rare, red-legged variant
salamander against most predators. Adults are dark salamander that may be a mimic of the red-legged
blue or black, with many small silver Jordan’s salamander). The mountain
Length 41⁄2 – 8 in or gold spots. In the breeding season, Length 23⁄4 – 41⁄4 in dusky salamander lives on land once
(11.5 – 20 cm) males develop a swollen vent (cloaca) (7 – 11 cm) it has matured, and spends daylight
Habit Wholly terrestrial and a large gland under the chin. The Habit Wholly terrestrial hours underground. At night, it
Breeding Variable slimy salamander is nocturnal, living in Breeding Spring, summer, emerges to feed on insects and other
season season and fall small animals. It is protected by a toxic
Status Least concern wooded hillsides Status Least concern skin secretion and, if threatened, it
and ravines. sometimes sheds its tail. During the
breeding season, adults mate on land.
Location E. USA The male stimulates his prospective
partner by rubbing a pheromone onto
costal Location E. USA her skin, and abrading the skin’s
grooves surface with specialized teeth. The
This large, slender-bodied salamander long tail female deposits a cluster of 12 – 20
gets its name from the gluelike slime small silver eggs in a cavity beneath a tree trunk or
that it exudes when handled. The spots on tail underground, guarding them until they
hatch. The larvae develop in streams.
Plethodon cinereus and to attract females. In the The mountain dusky salamander Adults are particularly active after rain,
breeding season, females inspect belongs to a group of about a dozen but they spend the winter underground.
Red-backed the droppings, preferring to mate with North American species that are
salamander males that have eaten a lot of termites. so similar in their appearance, that long,
Males can reproduce every year, but it takes expert knowledge to tell them slender tail
Length 21⁄2 – 5 in females are fertile only in alternate years. apart. Like most of its relatives, it has
(6.5 – 12.5 cm) The eggs are attached to the roofs of a long, slender body, protruding eyes,
Habit Wholly terrestrial underground chambers. and a long, cylindrical tail. It is usually
Breeding Fall to
season early spring brown to
Status Least concern red legs

Location S.E. Canada,
C. and E. USA

This small salamander is dark gray
or brown, usually with a broad red or
red-brown stripe along its body and tail.
Males use feces to mark their territory

446 NEWTS AND SALAMANDERS

Batrachoseps attenuatus Pseudotriton ruber It has a thick body, a relatively short Aneides lugubris
tail and legs, and a dense scattering
California slender Red salamander of black spots over its red or orange- Arboreal salamander
salamander red skin. Largely nocturnal, it feeds
Length 4 – 7 in mainly on invertebrates and other Length 41⁄4 – 7 in
Length 3 – 51⁄2 in Location E. and S.E. USA (10 – 18 cm) salamanders. To ward off predators, Location W. USA (11 – 18 cm)
(7.5 – 14 cm) Habit Mostly terrestrial the red salamander raises its tail and (California) Habit Terrestrial/
Habit Wholly terrestrial Breeding Any time of year, waves it, but its color may also act Arboreal
Breeding Not known season usually summer as a defense. Although it is harmless, Breeding Not known
season Status Least concern its red markings closely resemble season
Status Least concern those of the toxic young eastern Status Least concern
newts (see p.444)—a similarity that
Location W. USA may be a form of protective mimicry.
(California, Oregon) The female lays about 70 eggs,
attached to the underside of logs or
This salamander lives mainly underground Brilliantly colored when young, but rocks, and sometimes in water. Adult This long, slender, brown and white
and under logs and rocks, emerging at becoming progressively darker with red salamanders usually spend the salamander has flattened toe tips and
night after rain. Its extremely long, age, the red salamander is found in winter underground. a prehensile tail that enable it to climb
slender body enables it to enter very damp places, springs, and cool streams trees with ease. The relatively large,
small crevices. It is dark brown or black, in many eastern states of the USA. triangular head contains prominent jaw
with a brown, yellow, or red stripe along muscles that are used in fights between
the back, and tiny, 4-toed limbs. When in individuals, or in defense—for instance,
danger, the California slender salamander against predatory snakes. It lives below
coils and uncoils its tail rapidly, and may ground in winter and dry weather. The
shed it if attacked. female lays 12 – 18 eggs in an
underground chamber.

AMPHIBIANS Bolitoglossa mexicana Ensatina eschscholtzii Oedipina quadra in Honduras—and gets its name from
its elongated body and tiny limbs. It
Mexican mushroom- Ensatina salamander Honduran lowland is jet black on upper parts and sides,
tongue salamander worm salamander slightly paler underneath; its tail is nearly
Length 21⁄4 – 31⁄4 in rectangular in cross section—hence its
Length 43⁄4– 6 in Location W. USA (6 – 8 cm) Length 43⁄4 – 71⁄2 in scientific name. The species belongs to a
(12 – 15 cm) Habit Wholly terrestrial (12 – 19 cm) family of American lungless salamanders
Habit Arboreal/ Breeding Fall to spring Habit Terrestrial (including Plethodon, Bolitoglossa and
Terrestrial season Breeding Not known allies) that breathe through their moist
Breeding Any time, except Status Least concern season skin. They have diversified into more than
season dry/cold periods Status Not evaluated 200 species in the wet forests of Central
Location S. Mexico to Status Least concern Location Central America and northern South America, where
Central America they feed on tiny invertebrates, such as
springtails. These tropical salamanders
With its prehensile tail, feet with adhesive This is one of many new species of do not need free-standing water to
pads on the base, and small size, this rain-forest salamanders discovered breed because they have evolved direct
nocturnal animal is specially adapted in Central America in recent years. It development: eggs laid in the moist
for climbing trees and moving around was found while sorting through leaf habitat hatch into miniature forms
on the smallest of branches. It has a litter of pristine wet broadleaf forest of adults, bypassing an aquatic
mushroom-shaped tongue, which it flicks larval stage.
out to catch insects. The bronze or pink This nocturnal animal lives in damp leaf Eurycea guttolineata
coloring, with black marbled patterning, litter and under logs, and is especially orange, or brown, with dark brown or
acts as a warning that this salamander active after rain. It has a short body, Three-lined black stripes down the middle of its
will emit noxious secretions from its long legs, and prominent eyes. Its color salamander back and along the sides. It lives under
skin if attacked. depends on the area in which logs and rocks in damp areas near
it lives: it may be uniformly brown, or springs and streams; winters and dry
black with white, yellow, orange, or pink Location E. USA Length 4 – 7 in periods are spent underground. Spiders,
blotches. The round tail, which narrows (10 – 18 cm) flies, beetles, and ants are the main diet
abruptly at the base, is used in defense. Habit Wholly terrestrial of this predator, which feeds at night,
The salamander lifts it up and waves it Breeding Fall and
around, emitting a distasteful secretion season early winter dark stripe
to deter predators; it may also shed Status Least concern along back
its tail if attacked. During the breeding
season, the male has a longer tail A long and slender body especially after it has rained. During
and develops a swollen cloaca. The with 13 or 14 costal grooves, the breeding season, the male develops
female lays 8 – 20 eggs in clusters prominent eyes, and a very 2 fleshy projections on the upper lip, 2
under logs. long tail characterize this protruding teeth, and a swollen cloaca.
salamander. It is yellow, Eggs are laid in damp cavities.

CAECILIANS 447

Caecilians Ichthyophis glutinosus Gegeneophis mhadeiensis

Ceylon caecilian Mhadei caecilian

PHYLUM Chordata These limbless, wormlike animals Length Up to 18 in Length 7 – 8 in
CLASS Amphibia form the smallest of the 3 major groups (45 cm) (18 – 20 cm)
ORDER Gymnophiona of amphibians. They are rarely seen by Habit Terrestrial/ Habit Wholly terrestrial
humans, because they live either in soil Burrowing Breeding Unknown
FAMILIES 10 Location Sri Lanka Breeding Not known Location India season
burrows or underwater, and are found only season Status Data deficient
Status Least concern

SPECIES 205 in humid, tropical areas. Caecilians have

varied life cycles: some species lay eggs,

but in others the eggs are retained in the female’s body and With its long, thin body covered with
well-defined rings, and a short tail,
nourished by secretions produced by the oviduct until the the Ceylon caecilian resembles a
large earthworm. It is brown with
eggs hatch and the young are released by live birth. a bluish sheen, and has a pair of
small, retractable tentacles between
Anatomy tentacle the nostrils and the eyes that enable it This caecilian was described in
below eye to pick up odors. This caecilian lives 2008 and is known from only 3
Caecilians have long, underground, mostly in muddy soil and specimens, all collected from 2
thin, black or brown SENSORY TENTACLES swamps, where it feeds on worms adjacent localities in the Western
to pink bodies and A unique feature of caecilians and other invertebrates. The female Ghats of India. They were found near
no limbs. They have is the small tentacle located just coils around her eggs to protect them. human habitations or on agricultural
rudimentary eyes and rely on below each eye. This collects land—a factor that may indicate
a good sense of smell to find chemical information, which is used the species can tolerate human AMPHIBIANS
food and mating partners. Some to locate prey. Caecilians feed mainly disturbance. It is dark brown with a
resemble very large earthworms on earthworms, which they catch pinkish head, and with paler rings on
and burrow into soft soil or mud, with their sharp, curved teeth. its “segments.” Its habits are not known,
using their pointed, bony head but other members of the genus lay
as a shovel. All but one species eggs on land and lack a larval stage.
have lungs. The aquatic caecilians
resemble eels; they have a fin
on the tail that enables them
to swim powerfully.

Caecilia tentaculata Dermophis mexicanus Siphonops annulatus blue body, encircled by white stripes and
numerous rings. Like other caecilians, it
Linnaeus’ caecilian Mexican caecilian Ringed caecilian uses its tentacles to pick up the odors
of nearby prey—usually worms and other
Length 18 – 25 in Length 4 – 231⁄2 in Length 8 – 16 in invertebrates. When attacked, it
(45 – 63 cm) (10 – 60 cm) (20 – 40 cm) produces a distasteful secretion. The
Habit Terrestrial/ Habit Terrestrial/ Habit Wholly terrestrial ringed caecilian lays its eggs in soil,
Burrowing Burrowing Breeding Not known where they hatch into miniature adults.
Breeding Not known Breeding Not known season
Location N. South season Location Mexico to season Location N. South Status Least concern
America Status Least concern Central America Status Vulnerable America

This large caecilian has a thick, glossy Also known as the South glossy, dark
flattened body, gray or black skin American caecilian, this blue skin
above and light brown below, and
a wedge-shaped snout. It has no This caecilian lives in the same region forest-dwelling amphibian short tail
tail and, unlike other caecilians, its of the world as several amphisbaenians lives in soil and resembles a
rear end is covered by a hard shield. (see p.431), and is superficially similar large, thick earthworm. It has a long, slender, glossy black body, dark
Tiny scales are present in the skin in to them, although it lacks legs. Gray, a relatively short, stocky, dark gray below, encircled by 80 – 95 rings.
the 100 – 300 grooves that cover the brown, or olive-green above, it has Its tail is flattened from side to side, with
body, and the tentacles, which are well-defined rings around its body, Typhlonectes compressicauda a slight fin along the top. The Cayenne
lower than in other caecilians, are not and a pointed, burrowing snout. It feeds caecilian produces toxic secretions
visible from above. Very little is known chiefly on invertebrates, but also on Cayenne caecilian when it is attacked, usually by fish.
about its behavior, since it lives buried in lizards, and is completely subterranean, The eggs develop into larvae inside the
loose soil, but it is known to be living in a variety of habitats where there Length 12 – 231⁄2 in body of the female, who gives birth to
a solitary animal that lays eggs. is loose soil. The egg and larval stages (30 – 60 cm) miniature adults.
are completed inside the female’s body. Habit Wholly aquatic
After an extended gestation period, Location N. South Breeding Not known well-defined rings
the mother gives birth to live young. America season around body
Status Least concern

An inhabitant of rivers, lakes, and
streams, the Cayenne caecilian
resembles an eel in shape and
the way in which it swims. It has

448 FROGS AND TOADS

Frogs and toads

PHYLUM Chordata Frogs and toads form much the largest and best Feeding
CLASS Amphibia known of the 3 groups of amphibians. As adults,
ORDER Anura they have no tail—unlike other amphibians, their All frogs and toads are carnivores that feed on live prey rather than
tail is absorbed during metamorphosis from carrion. Unable to chew or break up food in their mouth, they have
FAMILIES 56 to swallow their prey whole. However, many species can eat large
animals (including mice, birds, and snakes), and a single meal can
SPECIES 6,700 the larval to the adult stage. There is no clear meet their energy needs for a long time so that they do not need
to feed often. Few species are active hunters, the most common
distinction between frogs and toads: the term feeding method being to wait until prey comes within range, either
of their long, sticky tongue or of a forward, open-mouthed lunge.
“toad” is often used to refer only to members of the genus Bufo,

but it is also used more widely to describe any slow-moving, SWALLOWING FOOD

terrestrial species with a squat body and rough, warty skin. Frogs and toads typically shut their
eyes when swallowing their food. As
The larvae of frogs and toads, known as tadpoles, mainly their eyelids close, the eyeballs are
rolled and pushed downward to
feed on algae or plant material and characteristically have increase pressure in the mouth.

a spherical body that contains the long, coiled gut required CATCHING

by such a diet. In many adults, the back limbs are modified

for jumping; they are much longer and more muscular than

the front limbs. Most frogs and toads live in damp habitats,

near the pools and streams in which they breed, but there

are several species that live in arid areas. The greatest diversity SWALLOWING

of species is found in the tropics, particularly in rain forests.

AMPHIBIANS Anatomy

Frogs and toads have a short, rigid body, a large, wide
head, and, in most species, front limbs that are much
smaller than the back limbs. The back limbs contain an
extra section, just above the foot, that is not present in
other amphibians. Most species have large, protruding
eyes and a conspicuous eardrum (tympanum) on each
side of the head, reflecting the importance of the senses
of vision and hearing. The mouth is large, and many
species have an adhesive tongue that they can flick
out at high speed to catch their prey. The female is
usually larger than the male, but males of many species
have thicker and more muscular front limbs. These enable
the male to grip the female securely during mating.

webbing extends FEET
to ends of digits
Frogs and toads have 4 digits
WEBBING on the front limbs and 5 on the
back. In many species, especially
circular adhesive those that spend much of their
pad life in water, the digits on the limbs
have webs of skin between them.
DISKS widely spread Many frogs that live in trees have SPAWNING SITES
digits for gripping disk-shaped adhesive pads on the Because bodies of water suitable for breeding are often scarce, many frogs
large area ends of their digits, which enable and toads, such as these European common frogs, form large breeding
them to gain a secure foothold groups, with frogs often converging from a wide area. The collective mass of
large tubercle, on smooth, vertical surfaces. eggs is also able to retain more heat, enabling the tadpoles to hatch sooner.
used for digging Burrowing species have horny Ponds and streams that dry up for part of the year are often used, since they
TUBERCLES protuberances, called tubercles, do not support other animals that eat eggs and tadpoles.
on their back feet, which they use
to excavate soil. FINDING A MATE
Many male frogs and toads call to attract
SKIN FROG SKIN TOAD SKIN females to the spawning site. The calls made
by males enable a female to find a mate.
The skin of frogs and toads is highly More importantly, each species has its own
variable. At one extreme, the skin of characteristic call, which helps a female to
some toads is so tough that it is used find a mate of the same species in breeding
as a substitute for leather; at the other, pools used by several species at once. In many
there are frogs with skin so thin that species (such as the aquatic frog, right), the
their internal organs can be seen effectiveness of the call is enhanced by one
through it. Toads typically have rough, or more vocal sacs. The male fills himself with
dry skin that is covered with warts and, air, which is moved back and forth between the
in some species, small spines. Frogs lungs and vocal sacs; sound is produced as
generally have smooth, moist skin. it passes over the vocal cords in the larynx.