Exploring the World of Reptiles and Amphibians

RATTLESNAKES

Rattle-less Rattlesnakes because the islands did not hold large hoofed
Not all rattlesnakes have rattles. One or two mammals that might trample them.
rare species that live on small islands in the
Gulf of California cannot rattle their tails, even Growing Up
though they are descended from snakes with Newborn rattlesnakes have no rattle. The rattle
working rattles. Snake experts think that these begins as a tiny button and develops in the
rattle-less snakes reached the islands either by first year or so as the young snake grows and
swimming or after being stranded on rafts of molts several times. Young rattlesnakes may not
floating vegetation. Once on the islands, the
snakes may have gradually lost their rattles so A tightly coiled and rattling blacktailed
that they could climb trees to hunt birds more rattlesnake is a rare sight. These snakes usually
effectively. The rattle may also have been lost retreat when they are disturbed.

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RATTLESNAKES

be able to sound a
warning, but they are
still extremely dangerous.
When biting in defense, adults
may deliver less venom or none at
all. Young snakes do not have the same
control and so they are just as deadly.

The Deadliest Rattlesnake Rattlesnake bites are rare. The people who are
The western diamondback is considered to be bitten either step on the snakes, or prod or poke
the most dangerous snake in North America. them on purpose. If you see a rattlesnake in the
More people die from bites from this snake open, leave it alone and move far away.
than any other. It is dangerous because of its
large size, and also the strength and quantity DID YOU KNOW?
of its venom. Although they stand their ground
and strike if provoked, these snakes are not The venom of most rattlesnakes
as aggressive as people imagine. They would acts on the blood. But the venom of
rather slither away, shaking their rattles to warn the Mojave rattlesnake attacks the
an enemy not to follow. Although the bite can nerves. It works very quickly, which
kill a person, an antivenom is available. Captive makes the Mojave very dangerous.
diamondbacks are milked for their venom, The eastern diamondback rattlesnake
which is used to make the antivenom. is as venomous as the western
diamondback, but it is rarer and
found over a much smaller area.

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RED SALAMANDER

The red salamander is one of the most colorful
amphibians in North America. The bright orange,
scarlet, or crimson color of the young salamanders

tends to darken with age.

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Throughout the animal kingdom, bright colors Newts and Salamanders
warn potential predators that an animal might
be poisonous. The predator recognizes these colors and Fact File
avoids these species. Red salamanders are only mildly
poisonous, but their coloration closely matches that RED SALAMANDER
of young eastern newts, which are highly poisonous. Pseudotriton ruber
Scientists believe they benefit from resembling their Family: Plethodontidae
poisonous relatives. Predators are fooled into avoiding Order: Caudata
red salamanders, too. When threatened, they arch their
body and raise their tail just like young eastern newts. Where do they live?: Eastern
United States
Red salamanders live in the eastern United States,
where they can be found in damp places such as boggy Habitat: Streams, springs, and
fields and wooded areas. By day, they rest in burrows in bogs in meadows and wooded areas;
soft mud beneath rocks and logs. They emerge to feed young grow up in water
at night. Small invertebrates such as insects make up
most of their diet. Large red salamanders go after Size: 3.75–7 in. (9.5–18 cm)
bigger prey such as frogs and other salamanders.
Appearance: Stout with short,
Life Cycle thick tail; orange to crimson body
Red salamanders breed in summer. The female’s eggs has small black spots; bright color
are fertilized by a capsule of sperm dropped by the darkens with age
male, which she is able to store for several months. She
usually lays her eggs in fall or winter in a wet site such Diet: Small invertebrates and
as a spring. Up to ninety eggs are glued to the underside other salamanders
of stones. She stays with the eggs until they hatch about
twelve weeks later. The larvae (young) grow up in water. Breeding: After internal fertilization,
They develop slowly in the still water of pools, taking females lay 70–90 eggs, which
up to three and a half years to transform into adults. attach to rocks; eggs hatch into
aquatic larvae after 3 months
Red salamanders have a stout build, with a thick
body, small legs and a short tail. The upper body Life span: Not known
is speckled with small black spots.
Status: Lower risk—least concern

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RETICULATED PYTHON

The reticulated python is one of the world’s biggest
snakes and also one of the most feared since it has been

known to kill people. Like other pythons,
the reticulated python kills by constriction.

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The reticulated python is the world’s second snakes and lizards
largest snake, after the anaconda. Like all snakes,
these pythons never stop growing. They grow quickly Fact File
during their early years, but the rate slows as they
become adults. These snakes have a complex web of RETICULATED PYTHON
brown, black, yellow, and white markings on their Python reticulatus
large, muscular bodies. This provides camouflage as Family: Pythonidae
the python lies in wait for victims, hiding in water or Order: Squamata
among vegetation. It hunts medium to large mammals Where do they live?:
and birds. The prey is wrapped in the snake’s coils Southeast Asia
which then tighten and suffocate the victim. Habitat: Fields, forests, plantations,
riverbanks, and towns
Breeding Habits Size: Usually 15–18 ft. (4.5–5.5 m)
Reticulated pythons produce large numbers of eggs. but can reach up to 33 ft. (10 m)
Females have been known to produce more than Appearance: Huge, muscular snakes
100 eggs at one time. The female coils around her eggs with large broad head; markings
to warm and guard them. The hatchlings measure 24– come in complex brown, black, and
30 inches long. Reticulated pythons are able to breed yellow with white triangles
when they reach about 9 to 10 feet long, which usually Diet: Birds, reptiles, and medium
takes five or six years. to large mammals
Breeding: Females lay between
Pythons and Humans 60 and 100 eggs, which hatch
Of all the constrictors, reticulated pythons are the after about 90 days
most dangerous to people. Not only are they huge, but Life span: Not known
they are also drawn to towns and villages by plentiful Status: Common, but becoming
prey, such as chickens and rats. There are accounts of rarer because of hunting and
reticulated pythons eating people, especially children, habitat loss
although this would be extremely rare.
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Reticulated pythons have large heads. The complex
pattern on their bodies gives these snakes their
common name—reticulated means “netlike.”

ROUGH-SKINNED NEWT

The skin of the rough-skinned newt contains a poison
powerful enough to kill a dog. This is one of the most
poisonous newts in North America. Poison helps the newt

defend itself from predators such as snakes.

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Rough-skinned newts live along the Pacific coast Newts and Salamanders
of North America, from southeastern Alaska to
California, where they are found in damp forests in Fact File
hilly or mountainous country. These shy amphibians
emerge at night to hunt insects and worms on the ROUGH-SKINNED NEWT
ground, and tadpoles and frogs’ eggs in the water. Taricha granulosa
Family: Salamandridae
Warning Colors Order: Caudata
The rough-skinned newt is a poisonous species, and
it advertizes this fact with its bright orange or yellow Where do they live?: Western
belly. Most snakes and other predators recognize the North America, from southeastern
bright belly of these newts and know not to attack. Alaska to California
If threatened by a predator, the newt arches its back
and raises its head and tail to reveal the bright belly. Habitat: Damp forests and
meadows in uplands; larvae grow
Breeding Habits up in lakes, ponds, and pools
Rough-skinned newts mostly live on land as adults,
but return to water to breed. They usually breed in Size: Head–tail length 6–8.5 in.
spring, but newts in high, cold mountains breed in fall. (15.5–22 cm)
Fertilization (the fusing of egg and sperm) takes place
inside the female, and a packet of sperm from the male Appearance: Sturdy newt with
fertilizes the eggs. After mating, the female lays her eggs rough, warty skin; dark brown or
one by one in the water, attaching them to submerged black upper body, orange or yellow
plants. The young hatch out as aquatic larvae. They underside, sometimes with dark
grow, develop, and metamorphose (transform) to markings
become land-dwelling adults. This usually happens by
the end of summer. In the mountains, young pass the Diet: Insects, frogspawn, tadpoles,
winter as larvae and become adults the following year. and worms

Rough-skinned newt have thick bodies, short legs, Breeding: After internal fertilization,
and large heads. The upper body is dark to conceal it females lay eggs one at a time and
from above. The underside is orange or yellow. fix them to water plants

Life span: Not known

Status: Lower risk—least concern

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SALAMANDERS

One of the three main groups of group of vertebrates (animals with backbones)
amphibians, salamanders have to leave the sea and live on land. They evolved
long, slender bodies. Different from a group of fishes that had developed lungs
species lead very different lives, and fleshy, leglike fins. Salamanders and newts
with some kinds living on land are the group of amphibians that most closely
and others living in the water. resembles those fishy ancestors, with their long,
slender bodies and powerful tails.
Salamanders and newts are one of the three
main groups of amphibians. They are more The marbled salamander is a medium-size
closely related to the caecilians than they are to species that can reach up to 4.25 inches in length.
the frogs and toads. Amphibians were the first The white bars across the black body and tail
are a distinctive feature of these salamanders.

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There are more than 400 species of newts Fact File
and salamanders, which make up the scientific
order (group) called Caudata. Some species SALAMANDERS AND NEWTS
are aquatic (water-dwelling), while others are Order: Caudata
terrestrial (live on land). Most land-dwelling Families: Over 400 species in 10 families
species live at ground level, but some are good Where do they live?: North and South
climbers and can be found in trees. Some America, Central Asia, Europe, and North Africa
species live in dark caves and underground
streams. As adults, newts live on land, but they Equator
always return to water to breed. Apart from
this behavior, there is no scientific difference Habitat: Generally moist places such as
between newts and salamanders. brooks, ponds, and streams
Size: Varies from 5 in. (13 cm) to the 6 ft.
Salamanders and newts mainly live in damp (1.8 m) giant salamander
places in cool, temperate regions of the world. Appearance: Most salamanders and newts
Most are found in the Northern Hemisphere, have small heads, with long, slender bodies,
especially parts of Central Asia, Europe, and short legs, and long, thick tails. Most species
North America. Many small, agile species have four legs, but some have only 2 legs
inhabit parts of Central and South America. or very short legs. Skin is smooth
They are found in North Africa but not south Diet: Small species eat invertebrates (animals
of the Sahara Desert. There are no salamanders without backbones); larger species eat small
in Southeast Asia or Australia. frogs, reptiles, and rodents
Breeding: Females lay eggs in the water,
Shape and Movement which mostly hatch out as larvae; in some
In terms of their appearance, salamanders and species the eggs develop inside the mother;
newts resemble the intermediate stage between others retain larval features as adults
the other two groups of amphibians—the Life span: Not known
caecilians, and frogs and toads. Unlike frogs Status: Varies according to species,
and toads, which have squat bodies with no from common to scarce
true tail, salamanders and newts have a long,
slender body and thick tail. Unlike legless,
worm like caecilians, most salamanders have
four limbs. These legs are not as strong as the
back legs of frogs. Some aquatic salamanders
have only small front limbs and no back legs.

309

SALAMANDERS

The small group called the sirens have only Breathing
front limbs, while another group, called the Like other amphibians, most salamanders
amphiumas, have tiny, almost useless limbs. breathe using lungs and through their moist,
smooth skin. Some species use their skin to
Salamanders and newts cannot leap like frogs. breathe more than others. Whether in water
Land-dwelling species generally move in two or on land, salamanders often raise and lower
different ways. When moving slowly, they walk their throat in a pumping action. This helps
on all fours, holding their body off the ground.
When frightened they throw their body into DID YOU KNOW?
a series of S-shaped curves, in a similar way as
caecilians, legless lizards, and snakes. Some salamanders can shed their
tail when attacked. The twitching
Salamanders and newts have fairly small tail distracts the enemy, while the
heads with little eyes. Their most important salamander makes its getaway.
sense is smell. Salamanders and newts use scent Californian newts give off a
to track their food and also to find a mate. highly poisonous fluid to defend
themselves against attack.
1
These illustrations show various species of
2 salamanders and newts: western Chinese
mountain salamander (1); Japanese clawed
5 salamander (2); black crocodile newt (3);
mudpuppy (4); olm (5); greater siren (6); and the
3 two-toed amphiuma (7).
4

6
7

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SALAMANDERS

to move air in and out of the lungs. The gas The barred tiger salamander is a large species,
oxygen also enters the body through the lining with a broad head and protruding eyes. The
of the mouth, which is rich in blood vessels. dark skin is covered with large yellow blotches,
Waste carbon dioxide gas, the by-product of which advertizes that it is poisonous to predators.
respiration (process of breathing and respiring),
passes out through the mouth. Most young land-dwelling adults hunt vertebrates (animals
salamanders breathe using large, feathery gills with backbones)â•‹including frogs and mice.
on the sides of their head. Some salamanders Many species eat smaller salamander species,
and newts keep these gills as adults. and some are cannibals, which means they eat
members of their own kind.
Feeding Techniques
All salamanders and newts are carnivorous— Aquatic salamanders open their mouths to let
they eat meat. These animals catch live prey by in water and their small prey. Salamanders that
picking up scent molecules from the air or by live on land creep up on their prey. When in
spotting movement. Salamanders and newts range, they dart out their long, sticky tongues.
feed on whatever prey is most abundant. The
size of prey varies according to the size of the Reproduction
salamander. So, newly hatched salamanders feed Salamanders and newts vary in their breeding
on smaller aquatic creatures, while the larger habits. Most have a life cycle that involves three
distinct stages: egg, larva (young), and adult.

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SALAMANDERS

Adult Adult

Terrestrial salamander

ONâ•‹LAND

Eft stage Larval stage
in egg
Amphibious newt Egg mass

INâ•‹WATER

Adult with gills

Egg Courtship Free- Aquatic axolotl
Gilled larva in water swimming
larva Egg mass

Some hatch out from eggs as water-dwelling These illustrations compare the life cycles of
larvae, which breathe using feathery gills. When salamanders and newts. Many salamanders live
the larvae are full-grown they metamorphose, entirely on land, newts return to the water to breed,
which means they transform into a new adult and the unusual axolotl is completely aquatic.
form. During this process, the salamanders and
newts lose their gills and start to breathe air DID YOU KNOW?
through their skin and their newly formed
lungs. Not all species undergo this amazing Some newts become more
transformation. This depends on whether the brightly colored in the breeding
species lives on land or in the water. season to attract mates.
Some salamander species
Newts mostly live on land as adults, but that live in caves have tongues
breed in water, and are known as amphibious that are almost as long as
species. Larvae pass through an intermediate their bodies.
stage, called an eft, before becoming adults.

312

SALAMANDERS

Land-dwelling salamanders lay relatively few sirens spend all their lives in the water, where
large eggs in damp soil. The eggs contain a rich they breathe using their special feathery gills.
supply of yolk, which feed the larvae as they Finally, the three species of amphiumas have
develop inside the egg. The larvae then hatch eel-like bodies with tiny limbs.
out as miniature versions of the adults. Female
salamanders often guard their eggs. In a few EFFECTIVE Defense
species, the eggs develop inside the female so
that she gives birth to well-developed larvae Salamanders such as the northern
or fully formed young. spring salamander are shy, secretive
animals that are mainly active at night.
Aquatic salamanders live and breed in the A nocturnal lifestyle reduces the risk
water. Females produce large numbers of small of being hunted by predators. Many
eggs, which then hatch into free-swimming species have dull, mottled colors that
larvae. Some aquatic species can breed while blend in with their surroundings.
keeping the features usually associated with the Some defend themselves by producing
larvae, such as gills. This is called neoteny. The foul-tasting or poisonous fluid from
axolotl of Mexico is the best known example glands on their heads or tails. These
of an animal that shows neoteny. species are often brightly colored.
Predators see the warning colors and
Who’s Who Among Salamanders avoid the salamanders. A few are
The 400 or more species of salamanders are brightly colored but non-poisonous.
grouped into ten families. The largest group They escape attack by mimicking
is the lungless salamanders, which contains (copying) poisonous species.
about 285 different species. As their name
suggests, these species of salamanders do not
have lungs and breathe through their skin,
mouths, and throats. The next biggest group is
that of the newts and European salamanders,
which contains fifty-five different species. This
group includes the poisonous black-and-yellow
fire salamander. Mole salamanders number
around thirty species, including the extraordinary
axolotl. The giant salamander group includes
the North American hellbender. Four species of

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SALTWATER CROCODILE

This fearsome predator is the world’s biggest and
most dangerous crocodile. Famous for their attacks
on people, saltwater crocodiles have more to fear from

people who kill them for their valuable skins.

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The saltwater crocodile is found in a variety of crocodilians
habitats, including estuaries, rivers, swamps, and
the open ocean. They are the most aquatic of all the Fact File
crocodiles and spend little time on land. Some even
have barnacles growing on them, which is a sure sign SALTWATER CROCODILE
they spend a lot of time in water. Crocodylus porosus
Family: Crocodylidae
Crocodile Attacks Order: Crocodylia
Saltwater crocodiles are believed to kill as many as
1,000 people every year. They also attack small boats, Where do they live?: From eastern
even after the crew have been thrown into the water. India through Southeast Asia to
Experts think that the crocodiles mistake small boats Australia, and on Pacific islands
for rivals entering their territory.
Habitat: Coastal waters, lakes,
People also kill saltwater crocodiles, mainly for their rivers, swamps, and open ocean
valuable skins. So many were slaughtered in the second
half of the twentieth century, that their numbers fell Size: Around 16–23 ft. (5–7 m)
steeply. Saltwater crocodiles are now protected by law,
and the population is carefully controlled. Appearance: Large gray or brown
crocodile with broad snout and
Breeding Habits strong jaws
Males become territorial during the breeding season,
and fights often break out for the chance to mate. After Diet: Aquatic animals including fish
mating, the female builds a mound of plant debris on to the size of sharks; mammals to
the river bank. She lays sixty to eighty eggs in this nest, the size of buffalo
which she guards against enemies such as monitor
lizards. The young hatch after three months. The female Breeding: Female lays 60–80 eggs,
then carries the hatchlings down to the water in her which she guards until the young
mouth. She continues to care for them for several weeks. hatch about 3 months later

All along the jaws of a massive saltwater crocodile Life span: Not known
are large, triangular teeth that are very efficient
at tearing flesh from its prey. Status: Lower risk—least concern

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SAND LIZARDS

Sand lizards are a group of small, agile lizards
suited to living in deserts. Unlike most desert-
dwellers they are active by day, darting here and

there to catch insects.

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Sand lizards are closely related to the African desert snakes and lizards
lizards. Both are members of the large lizard family
Lacertidae. They are slender lizards with long legs and Fact File
tails and pointed snouts.
SAND LIZARDS AND AFRICAN
Sand lizards and African desert lizards live on the DESERT LIZARDS
ground but prefer different habitats. Desert lizards Pedioplanis (sand lizards)
inhabit sandy parts of southwestern Africa, including Meroles (desert lizards)
the Namib Desert. They have fringes of hairlike scales Family: Lacertidae
between their toes that act like flippers, allowing them Order: Squamata
to run across loose sand. Despite their name, sand
lizards prefer rocky or gravelly ground. They lack the Where do they live?:
toe fringes of the desert lizards. Namaqua sand lizards Southern Africa
dart among the ancient Welwitschia plants that dot the
landscape, searching for insects. This speedy lizard can Habitat: Rocky and sandy deserts
be active during the hottest parts of the day. When the
sand gets too hot, it raises its tail off the sand and does Size: 6–8 in. (15–20 cm)
a shuffling “dance,” raising one front leg and the
opposite back leg, then switching legs. Appearance: Small, slender lizards
with long legs and tails and pointed
Feeding and Breeding snouts. Color varies from buff and
Most sand lizards and desert lizards eat insects such as brown to reddish with light or dark
beetles, grasshoppers, locusts, and termites. One species markings. Desert lizards have fringes
feeds on smaller lizards, and the shovel-snouted lizard of fine scales between their toes
also eats seeds. These lizards lay small clutches of eggs
in burrows or holes under rocks. Some may breed at any Diet: Varies from seeds and small
time of year. Most species lay between three and eight insects to smaller lizards
eggs, while the wedge-snouted sand lizard lays just one.
The eggs usually hatch after about two months. Breeding: Females lay clutches
of up to 8 eggs that hatch after
Sand lizards are beige, brown, or reddish in color, about 60 days
with lighter or darker markings that blend in with
sandy surroundings, camouflaging the animals. Life span: Not known

Status: Very common in
suitable habitats

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SANDFISH

The sandfish is an unusual lizard that lives in loose
sand in deserts. It tunnels through the sand with
a swimming motion, flexing its body and tail
from side to side.

318

Sandfish live in hot deserts in North Africa and snakes and lizards
western Asia, ranging from Morocco in the west
to Iran in the east. They live in the loose sand of Fact File
wind-blown dunes, often near oases.
SANDFISH
Desert Dwellers Scincus scincus
The sandfish is well suited to a burrowing lifestyle. Family: Scincidae
The short, wedge-shaped head; slender, flattened body; Order: Squamata
and smooth, tight-fitting scales create a streamlined Where do they live?: North Africa,
shape that glides through sand. The toes have tiny Middle East, and western Asia
fringes that act like flippers, pushing against soft sand. Habitat: Sandy deserts
Size: 8.75 in. (22 cm)
Male sandfish are larger than the females. These Appearance: Small lizard with
lizards start to breed in May. After mating, the female wedge-shaped head and short tail;
lays a clutch of about six eggs, which take about two color is brownish-yellow with yellow
months to hatch. or brown spots and streaks
Diet: Some plant matter; insects,
Hunters and Hunted spiders, scorpions, and small lizards
Sandfish “swim” through the sand much like a fish Breeding: Females lay about 6 eggs,
swims in water. They can quickly dive below the which hatch after about 2 months
surface to escape predators. And they can surface Life span: Not known
just as quickly to seize prey such as insects, spiders, Status: Common in suitable habitats
scorpions, and smaller lizards. In turn, sandfish are
eaten by many desert creatures, including horned 319
vipers, fennec foxes, and monitor lizards. Sandfish are
also hunted by people who live in the desert. Children
are often given the job of catching these reptiles by
digging them from the sand. The lizards are either
roasted and eaten immediately, or dried.

The sandfish is suited to a desert life. Grooves on
the head direct sand away from the eyes, and the
ears are covered by fringed scales to keep out sand.

SEA SNAKES AND SEA KRAITS

Most people think that snakes species of true sea snakes and five species of sea
are land-dwelling reptiles, but kraits. Both groups are well suited to a life in
some species spend all of their the ocean, but true sea snakes are completely at
lives in the ocean. Sea snakes home in the marine environment. These snakes
use their highly toxic venom never venture onto land and are helpless there.
to kill their prey. By contrast, sea kraits regularly come ashore to
mate and lay their eggs, or just to bask in the
Sea snakes belong to the family of sun.
poisonous snakes that includes land-
dwelling mambas and cobras. Scientist divide Sea snakes live in the warm, tropical waters of
sea snakes into two groups—the “true” sea
snakes and sea kraits. There are about fifty Unlike sea kraits, all sea snakes are completely
aquatic reptiles and never leave the warm,
tropical waters in which they are found.

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the Indian and Pacific oceans, from the Arabian Fact File
Gulf, through Indian and Southeast Asian
waters, to New Guinea and Australia. One SEA SNAKES AND SEA KRAITS
species, the yellow-bellied sea snake, has a wider Family: Elapidae
distribution and is also found on the opposite Subfamilies: Hydrophiinae and Laticaudinae
side of the Pacific Ocean, off the coast of North Order: Squamata
and South America. Most sea snakes keep to
fairly shallow, inshore waters, but the yellow- Where do they live?: Coastal waters of Indian
bellied sea snakes lives far out to sea. and Pacific Oceans, from Arabian Gulf and India
through Southeast Asia to Australian waters;
Suited to the Sea yellow-bellied sea snake more widespread
The long body of a sea snake is flattened from
side to side, especially toward the tail, which is Habitat: Shallow waters, including river
oar-shaped. The scales on the underside are estuaries; yellow-bellied sea snake open ocean
narrower than those of land-dwelling snakes.
They form a ridge that acts like the keel of a Size: 18 in. to 9 ft. (45 cm to 2.7 m)
boat, helping to stabilize the reptile as it swims.
Sea snakes sweep their body and tail from side Appearance: Marine snakes with sideways-
to side to move. The oar-shaped tail pushes flattened bodies and paddle-shaped tails; some
against the water, driving the snake forward. species have small heads and thick bodies.
Sea snakes have glands (special cells) under Colors vary from brown, gray, or olive, some
their tongues that remove excess salt absorbed species have black and white bands and one
from the seawater. species is a striking black and yellow color

Sea snakes vary in color. Most are gray, brown, Diet: Crustaceans, eels and other fish,
or olive and blend in with the seabed. Some and fish eggs
species have black and white bands, while the
yellow-bellied sea snake is black and yellow. Breeding: True sea snakes mate in the water
Conspicuous markings warn enemies that the and give birth to between 2 and 18 live
snakes are poisonous and should be left alone. young at sea. Sea kraits breed on land and
lay between 6 and 20 eggs on beaches
A Seafood Diet
Like their land-dwelling relatives, sea snakes Life span: Not known
are formidable predators. They use highly toxic
venom to overcome slippery prey such as fish. Status: Mostly common

321

SEA SNAKES AND SEA KRAITS DID YOU KNOW?

All species of sea snakes hunt in the water. Turtle-headed sea snakes have blunt,
Some species, such as olive sea snake, feed on cone-shaped spines on their snouts.
a variety of prey, including crabs, cuttlefish, Eyelash sea snakes have raised scales
prawns, and squid. Most prefer just one type over their eyes that resemble spiky
of food—usually slow-moving fish that can be eyelashes. No one knows the purpose
trapped in rocky crevices. Eels are the favorite of these unusual scales.
prey of many sea snakes. The long and slender Yellow-bellied sea snakes can swim
bodies of these fish fit comfortably inside the almost as well backward as they can
snake’s long, thin stomach. Sea snakes look for forward. They do this by reversing their
eels as they cruise over the seafloor. Some hold normal forward-swimming movements.
onto their prey after striking, until their venom
takes effect. Others release their victim and

The yellow-bellied sea
snake is one of the few
reptiles that lives out in
the open ocean, where it
hunts fish and other small
prey.

322

SEA SNAKES AND SEA KRAITS

Breathing Part of it extends backward, forming an
air store that supplies the snake when
Like all reptiles, sea snakes and sea kraits diving. The large lung may also help with
such as the banded sea krait (below) take buoyancy (keeping afloat). Some sea
in oxygen from the air using lungs. They snakes also absorb oxygen dissolved in
do not have gills like fish, so they must water through their skin. They may take
surface to breathe every so often. Their in one-fifth of their oxygen in this way.
nostrils are located on top of their heads
so they can breathe without lifting their Sea snakes usually look for food in
heads from the water. Special valves cover shallow water and come up to breathe
the nostrils. These valves close tightly every thirty minutes or so. Sea kraits
when the snake dives. surface more often, usually about every
five minutes. However, some types of true
Like other snakes, sea snakes have only sea snakes can dive to depths of 550 feet
one working lung. The lung is long and and stay under for up to two hours.
slender so that it fits inside the body. In
sea snakes, this working lung is very big.

323

SEA SNAKES AND SEA KRAITS

track it as it dies using their keen sense of smell. than most snakes. More offspring would weigh
the female down and hinder her ability to hunt.
Life Cycle
True sea snakes have different breeding habits Sea kraits come ashore to mate and again
than the sea kraits. True sea snakes mate in the to give birth. Yellow-lipped sea kraits migrate
water and do not come on land, not even to long distances to reach their breeding grounds
give birth. Most species mate on the seabed, but on remote beaches. They come ashore to mate
yellow-bellied sea snakes mate at the surface.
The eggs develop inside the female, and she The venom of the banded sea krait ranks
gives birth to live young. The female produces among the most toxic in the world. These snakes
just three or four young—a smaller number are very docile (not aggressive), however, so there
is little chance of a person being bitten.

324

SEA SNAKES AND SEA KRAITS

An ocean-going snake

The yellow-bellied sea snake is the only on small fish that live in this flotsam.
snake that ventures out into the open They may drift out into very deep water
ocean. These distinctive black and yellow with ocean currents. The bright colors of
reptiles gather out at sea at sites where yellow-bellied sea snakes warns potential
the ocean currents meet, and seaweed predators that they are poisonous, and
and other debris collects. The snakes prey they also have unpleasant-tasting flesh.

and remain on land for hours before returning DID YOU KNOW?
to the sea. When the female is ready to lay her
eggs, she swims ashore again, and lays a clutch Turtle-headed sea snakes eat only fish
of about a dozen eggs in a moist cave above the eggs. They search rocky crevices for the
high-tide mark. Several females may share the eggs laid by blennies and gobies. They
same cave. Other sea kraits lay their eggs in the have special muscles in their mouth to
sand or under foliage. The eggs of yellow-lipped suck up the eggs.
sea kraits hatch after sixteen to twenty weeks. “Thin-necked” sea snakes have slender
heads and necks. They can thrust their
A Freshwater Sea Snake heads right inside the narrow burrows
The Lake Taal sea krait is a contradiction in of eels to catch the slender fish.
terms—a sea snake that lives in fresh water.
The home of this unusual sea snake is a hollow, which was then flooded by seawater.
freshwater lagoon on the volcanic island of Sea snakes entered the lagoon via a channel that
Luzon in the Philippines. Scientists believe Lake was later closed by a further eruption, trapping
Taal was formed by a violent volcanic eruption the snakes inside. The lagoon gradually became
in ancient times. The eruption created a large less salty as it filled with rainwater. The snakes
survived and adapted to life in fresh water. The

325

SHARP-RIBBED NEWT

The sharp-ribbed newt is a fierce predator, hunting
out tadpoles, fish, and worms. Poison glands

protect these newts from attack, as do the sharp
ribs, which stick out through their skin.

326

Sharp-ribbed newts are common over much of Newts and Salamanders
Spain and Portugal, and across the Mediterranean
in Morocco. These amphibians spend almost all their Fact File
lives in water. They live in stagnant pools, streams, and
water-filled ditches, where they hide in the mud at the SHARP-RIBBED NEWT
bottom and surface for air. At night they hunt for fish, Pleurodeles waltl
insects, and worms, and will even eat their own kind. Family: Salamandridae
Order: Caudata
Poisoned Ribs
This newt has a mottled greenish-gray body, with a Where do they live?: Spain and
row of large orange warts down each flank. These are Portugal (except northern areas)
poison glands positioned over the tips of the sharp and northern Morocco
ribs that lie just beneath the skin. When captured by
a predator, the newt arches itself. This tightens the skin Habitat: Water-filled ditches, pools,
over the orange warts, and the tips of the ribs pierce the lakes, and sluggish rivers
skin through the poison glands, releasing poison. The
newt writhes around, repeatedly stabbing its attacker Size: 6–12 in. (15–30 cm)
with its poisoned ribs. With such a ferocious defense,
it is not surprising that most predators leave it alone. Appearance: Large, stocky newt
with large, flattened tail; gray-green
Life Cycle skin with a row of orange warts
Sharp-ribbed newts breed between September and running along its sides
March. A few days after mating, females lay between
200 and 300 eggs in clumps, fixing them to stones or Diet: Invertebrates, tadpoles, and
water plants. After five to fourteen days, the eggs hatch small vertebrates
into larvae. They feed and develop for between 50 and
150 days before transforming into adults. The time Breeding: After internal fertilization
taken to develop depends on the water temperature. (when eggs fuse with sperm), female
lays between 200 and 800 eggs
At up to 1 foot long, the sharp-ribbed newt is one of in clumps, which are fixed to water
Europe’s largest amphibians. It has a stout body and plants; the larvae take up to
a long tail, which is flattened from side to side. 150 days to transform into adults

Life span: Not known

Status: Near threatened

327

SIDEWINDER

The sidewinder is a rattlesnake that lives in the deserts
of southwestern United States, including Death Valley.

It takes its common name for the looping, sideways
movement that it uses to slither over loose sand.

328

Few animals can tolerate the desert heat, and the snakes and lizards
sidewinder is no exception. During the hottest part
of the day, this snake burrows into the sand to keep Fact File
cool. With much of its pale, mottled body covered by
sand, it is almost invisible. However, the top of the head SIDEWINDER
shows above the sand. The snake then emerges at night Crotales cerastes
to hunt for food. The sidewinder is unusual among Family: Viperidae
snakes because it does not have a home range where it Order: Squamata
lives, hunts, and patrols. Instead, it wanders the desert
randomly searching for prey. Where do they live?:
Southwestern North America
Hunting Techniques
Lizards are the sidewinder’s favorite food, especially Habitat: Deserts with sand dunes
whiptails, which move quickly by day but are very
sluggish at night. Sidewinders also hunt birds and Size: 24–30 in. (61–76 cm)
rodents. The snake kills by biting its prey with poisoned
fangs. Its venom is not as powerful as that of most other Appearance: Smallish, slender
rattlesnakes. If it gets the chance, it will also strike from rattlesnake with flat head and raised
its daytime burrow. It holds onto its prey until its venom scales over the eyes. Body is yellow,
takes effect, so it does not need to move out into the beige, pink, or grayish with darker
open, where it would be more noticeable. blotches and speckles

Breeding Behavior Diet: Lizards and mice
Sidewinders mate in April or May. Five months later, five
to eighteen live young are born. Young sidewinders have Breeding: 5 months after mating,
an unusual hunting technique—they use their tails to the females give birth to 5–18 live
lure lizards closer. The young snake moves its tail slowly young in late summer
over the sand so that it resembles a crawling insect.
Life span: Not known
The sidewinder moves by throwing its body
diagonally across the surface, leaving a trail of Status: Common
parallel J-shaped markings on the loose sand.

329

SIRENS

Sirens are unusual salamanders that have tiny front
legs and no back legs at all. These eel-like amphibians

live in the mud at the bottom of swamps and pools.
They are rarely seen and therefore poorly understood.

330

With their long, slender bodies, sirens look more snakes and lizards
like eels or snakes than amphibians. Growing
up to 35 inches long, they are among the largest Fact File
amphibians in North America. There are just four
species—the greater siren, the lesser siren, and SIRENS
two species of smaller dwarf sirens. Siren lacertina (greater siren)
Siren intermedia (lesser siren)
Sirens live in marshes, ponds, swamps, and water- Family: Sirenidae
filled ditches, spending most of their time burrowed Order: Caudata
in the mud and vegetation at the bottom. Sirens never Where do they live?:
come on land, even if their pond or swamp dries out. Southeastern North America
Instead, they burrow down into the mud. As the mud
dries, the slime covering their skin hardens, forming a Tropic of Cancer
cocoon that keeps the animal moist. The siren enters
an inactive stage called estivation. Its body processes Habitat: Swamps, ponds, and
slow down and it survives on fat stored in its tail. water-filled ditches
When rainwater fills the pool, the siren returns to life. Size: 7–35 in. (18–90 cm)
Lesser sirens can survive several months of drought. Appearance: Slender amphibians
Greater sirens stay up to five years in this inactive state. with large, feathery gills on the head;
long tail, tiny front legs, and no back
Breeding and Feeding legs; dark brown or olive with darker
Sirens are most active in summer, emerging at dusk spots, young may have red patch on
to hunt for young insects, snails, and other aquatic the snout and side of head
creatures. Scientists know little about the breeding Diet: Plants, amphibian eggs,
habits of these unusual amphibians. Experts think crayfish, insect larvae, and snails
that the eggs are fertilized by the male (when egg and Breeding: Lesser siren lays between
sperm fuse) outside the female’s body. Both lesser and 200 and 550 eggs, greater siren
greater sirens lay large quantities of eggs. The eggs lays up to 1,400 eggs singly or in
are probably laid in late winter and hatch about two groups. Eggs hatch after 8 weeks
Life span: Not known
The siren breathes under the water using the Status: Lower risk—least concernÂ

SKINKS

Skinks are one of the largest become established on some remote islands
lizard families. Most species live far out to sea. Skinks are the most abundant
on the ground, but some prefer reptiles in Australia, with more than 370 species.
to climb in the trees and others These fast, agile lizards are also common in
burrow in the sand or soil. Africa, India and Southeast Asia. The current
distribution of skinks suggests that they may
There are at least 1,400 species of skinks in have evolved on southern continents, and then
the family Scincidae. Experts divide this spread northward and westward.
large family into between 115 and 124 smaller
groups called genera. Skinks are found in every The common garden skink is often seen
continent except Antarctica, and they have even basking on top of rocks or paths in gardens
and parks across southern Australia.

332

Shape and Size Fact File
Skinks are generally long, slender lizards with
short legs and a tapering tail. Some skinks have SKINKS
tiny legs, however, and a few species have no Family: Scincidae
legs at all. Most skinks measure 3 and 13 inches Order: Squamata
from head to tail, but some are much larger. Where do they live?: Every continent except
The shape of the tail also varies. Some species for Antarctica
have long tails that can be twice the length of
the body. The stump-tailed skink of Australia Equator
has a short, fat tail that resembles its head. This
serves to confuse predators, which strike at the Habitat: Varies according to species but
wrong end of the skink. The tail also functions includes deserts, forests, and grassland;
as a food store. often found along rivers and streams.
Some are good burrowers, some live
Most skinks have rounded bodies covered in trees, while others are good swimmers
with smooth, flat, overlapping scales. Some Size: Usually around 5 in. (12 cm) but some
species have ridged scales that may help them larger species reach up to 14 in. (35 cm)
move about in their surroundings. The heads Appearance: Slender lizards with wedge-shaped
of most skinks are small and wedge-shaped, heads, tapering tails, and short legs
with large, bony plates protecting the top of Diet: Some species eat plants but most prey
the skull. The snout is often long and pointed. on small invertebrates (animals without
backbones) such as insects, slugs, and worms
Skinks can replace teeth lost through wear Breeding: Some females lay eggs, while others
and tear. New teeth move up from the inner give birth to live young
jaw to fill gaps created by the missing teeth. Life span: Not known
Most skinks have short, wide tongues that are Status: Varies from common to endangered
covered with tiny bumps.

Burrowing Skinks
Many skinks live under the ground, burrowing
through the soil or sand. Their bodies are well
suited to this lifestyle. Most have eardrums set
deep within the head, with a small opening to
keep out the sand or soil. The eyes have see-
through lower lids that protect the eyes from
dirt but also allow them to see underground.

333

SKINKS

Like most skinks, the burrowing species have even be a hindrance, so the burrowing skinks
small, wedge-shaped heads. The slender bodies have no front legs, or even no legs at all.
of these reptiles are covered with hard, smooth
scales that help the animal slide easily through Shedding the Tail
the soil or sand. Some burrowing skinks have Many skinks shed their tail when they are
small, weak legs and burrow by wriggling their attacked by a predator. The reptile can survive
long, bodies in the same way as a worm. In this without its tail, which often breaks off quite
form of movement, legs are of little use, and can cleanly. The tail distracts the enemy’s attention
while the skink escapes. For this reason, tails are
DID YOU KNOW? often brightly colored. For example, the African
fire skink has a red-and-black body and a blue-
A bright blue tongue gives the blue-tongued and-black tail. An enemy that focuses on the
skink its common name. When threatened, tail may well lose sight of the skink when the
it sticks out its startling tongue and hisses tail breaks off. For the same reason, young pink-
loudly. It also has a powerful bite. tailed skinks of Baja California have a brown-
An unusual skink from the island of and-cream striped body and a bright pink tail.
Madagascar off the coast of Africa lives on
the beach. It hunts crabs and small fish in 1 Five-lined skink 5 Fire skink
rockpools and is mainly active at low tide. 2. Berber skink 6. Blind burrowing skink
3. Cape skink 7. Monkey-tailed skink
12 4. Spiny-tailed skink 8. Three-toed skink

5

3 4 7
6

8

334

SKINKS

Suited to different habitats

Skinks live in many different habitats, they are able to retract their claws to run
including deserts, forests, and grasslands. over the ground.
Most species live on the ground, but a
few kinds are good climbers and forage in Some skinks spend much or part of
trees. Tree-dwelling skinks from Asia and their time in water. Eastern water skinks
Southeast Asia have long, tapering tails (below) live by streams and waterways
to help them balance when climbing. One and feed on insects and worms, and the
species, the large Solomon Islands tree occasional berry. The diving skinks of
skink, has a prehensile (gripping) tail like Madagascar live in forest streams. Their
a monkey, which it curl around branches. nostrils are high on their snouts so they
Many tree-dwelling skinks have a flat pad can breathe while swimming. These
under the toes that helps them climb. skinks are expert divers and strong
Cat skinks from hilly forests in India have swimmers. They can swim against the
sharp claws for climbing but, like cats, current to prey on creatures hiding under
stones on the riverbed.

335

SLIMY SALAMANDER

The slimy salamander is named for the sticky,
poisonous slime that it produces to protect itself from

predators. The male slimy salamander performs an
elaborate “dance” to win his mate.

336

Slimy salamanders live in moist forests and wooded Newts and Salamanders
hillsides in eastern North America. They spend
their days resting in burrows under rocks or logs. At Fact File
night, they emerge to hunt for insects such as ants and
beetles. The slime glands that give these salamanders SLIMY SALAMANDER
their common name are in their tails. When a predator Plethodon glutinosus
strikes, the salamander raises its tail and unleashes a Family: Plethodontidae
gluelike, poisonous slime. The sticky slime is a good Order: Caudata
defense, but slimy salamanders are still prey for some
birds, snakes, small mammals, and other salamanders. Where do they live?: Eastern
and southeastern United States
Courtship Dance
Slimy salamanders identify their mates by scent and Habitat: Damp forests, pine woods,
also through an elaborate courtship display. After and ravines
approaching a female, the male does a complex
“dance,” raising and lowering his back legs in turn Size: 4.5–8 in. (11–20 cm)
or both together. If he lifts both hind legs at once he
props himself up with his tail. Then he lifts and lowers Appearance: Slender salamander
his front legs. Moving closer, he rubs himself against with long tail; black or dark gray
the female and gently bites her. Finally, the male nudges with small silver spots
the female’s belly and the pair walk forward together.
He drops a capsule of his sperm, which she picks up Diet: Small invertebrates such as
with her reproductive organ. insects and worms

The sperm in the capsule fertilizes the female’s eggs Breeding: After internal fertilization,
inside her body. The female then lays up to three dozen females lay 5–34 eggs, which are
eggs in clusters, sticking them to an overhanging rock fixed to rocks. Eggs hatch after
or tree stump. She remains with the eggs until they 2 to 3 months
hatch two to three months later.
Life span: Not known
The slimy salamander has a slender body with
small, strong legs. The long, cylindrical tail is Status: Lower risk—least concern
about the same length as the head and body.

337

SLOW WORM

Slow worms are often mistaken for snakes, but they are
actually legless lizards. They are found in gardens and

parks across Europe and highly prized by gardeners
because they eat pests.

338

Slow worms are legless lizards that are found across snakes and lizards
much of Europe and into western Asia. They often
live in damp places with low-growing vegetation, such Fact File
as in cemeteries, hedges, overgrown gardens, and along
railway lines. Slow worms are shy, nocturnal (active SLOW WORM
at night) creatures. By day, they hide in ready-made Anguis fragilis
burrows or under rocks or concrete slabs. At night, Family: Anguidae
they emerge to feast on earthworms, insects, slugs, Order: Squamata
snails, and spiders. They track their prey by scent,
flicking out their tongue to gather scents in the air. Where do they live?: Most of
Europe into western Asia and
Slow worms have many enemies, including birds, cats, northwestern Africa
snakes, and weasels. They have strong jaws but rarely
bite. Instead, they shed their tails to confuse predators. Habitat: Damp places, including
Slow worms can live without their tails, which grow gardens, hedges, parks, riverbanks,
back slowly. Many adult slow worms have stumpy or and woodlands
regrown tails, resulting from attacks by cats.
Size: 12–20 in. (30–50 cm)
Life Cycle
Slow worms hibernate (spend the winter sleeping) Appearance: Legless lizard with
in vacant rodent burrows. Many slow worms may narrow head, small eyes, and long
hibernate together. They emerge by March, and mating tail. Shiny skin is a brown or coppery
takes place in May or June. The male pins down the color; females have a thin, dark line
female by biting her head and twisting his body around running down the back
hers. Mating can last up to ten hours. Females give
birth to six to twelve young from August to October. Diet: Invertebrates (animals without
They are born inside a membrane (skin) from which backbones) such as insects, slugs,
they escape by wriggling energetically. Males can breed snails, spiders, and worms
from the age of three; females breed from five years.
Breeding: Females give birth to
Slow worms have a slender, snakelike body but 6–12 live young around 8–12
the unmistakable head of a lizard. Many people weeks after mating
kill these lizards thinking they are snakes.
Life span: Up to 12 years in the
wild; up to 54 years in captivity

Status: Common

339

SMOOTH NEWT

Smooth newts are named for their smooth, velvety
skin. Like other newts, they breed in the water
where the male performs an elaborate mating
“dance” to attract his mate.

340

Smooth newts are small amphibians with compact Newts and Salamanders
bodies, well-developed legs, and large tails. This
species is the most abundant newt in northern and Fact File
central Europe, ranging from Britain eastward into
western Asia. They are so common that they are also SMOOTH NEWT
called common newts. Like other newts, smooth newts Triturus vulgaris
live on land as adults but return to water to breed. On Family: Salamandridae
the land they live in damp fields, gardens, and wooded Order: Caudata
areas. They are often seen in flooded gravel pits, village
ponds, and water-filled ditches. Smooth newts are Where do they live?: Northern and
shy creatures, hiding under stones and logs by day. At central Europe eastward into western
night they emerge to hunt small invertebrates (animals Asia
without backbones) such as insects, slugs, and worms.
Habitat: Damp fields, gardens, and
Differences in Appearance woodlands; larvae grow up in ponds
Smooth newts are yellow-brown or olive with dark
spots. Outside the breeding season, the males and Size: 4.5 in. (11 cm)
females are difficult to tell apart. Both are a similar
size—around 4 inches from the head to tail—with a Appearance: Small newt with
similar coloration. However, the males have a single smooth skin; yellowish-brown with
dark stripe running down the center of the back, while dark spots and yellow or orange
the females have two dark stripes that run either side of undersides; breeding males develop
the center line. Both sexes have a yellow or orange belly. a high, wavy crest
When the newts breed in the spring, however, the male
is much darker on the back. The male also develops Diet: Insects, slugs, worms, and
brighter colors on his belly. He also develops a high, other small invertebrates (animals
wavy-edged crest running along his back, which makes without backbones)
him more attractive to females.
Breeding: After internal fertilization,
Outside the breeding season, smooth newts spend females lay 200–300 eggs, one at
most of their time on the land. They hide under large a time, fixing them to water plants;
stones or in compost heaps, emerging at night to feed. larvae hatch after 10–20 days

Life span: Not known

Status: Lower risk—least concern

341

SMOOTH NEWT

Adult smooth The high, wavy crest of the male is the male immediately swims in front
newts live useful as well as decorative. When of her, blocking her way. He curls his
on the land but they are underwater, newts can add tail against his flank and waves it
return to their oxygen supply by absorbing energetically, wafting a special scent
to the water to oxygen through their skin. The tall toward the female. Having gained her
breed. They prefer crest of the male increases the surface interest, he turns and slowly moves
standing water area through which oxygen can be away in front of her, waving his tail.
with plenty of absorbed. This gives the male more If she follows, nuzzling his tail with
dense vegetation, time underwater before coming up her snout, he drops a capsule of
such as the edges for air, which in turn increases his sperm, which she picks up with her
of lakes and chance of breeding success. reproductive organ. The pair may
ponds, and water- repeat this courtship “dance” several
Breeding Time times before the female loses interest
Adult smooth newts breed in the and swims away.
water, such as freshwater ponds.
When the female enters the water, After mating, the female lays

342

Newts and Salamanders

between 200 and 300 eggs in water, newts. However, smooth newts have Black spots
at the rate of three to seven eggs conspicuous spots on their throats, cover the
per day. She attaches each egg to while palmate newts have pale, throat and flanks
submerged plants. The eggs hatch unspotted throats. The group also of the smooth
into larvae after a maximum of includes the great crested or warty newt and extend
twenty days. The larvae (young) newt. Larger than the smooth newt, on to the orange
look nothing like the adults. These the male great crested develops a tall, or yellow belly.
aquatic creatures have feathery gills jagged crest along his back during These colors
on their heads, which they use to the breeding season. In the same way camouflage the
breathe in water just like a fish. The as smooth newts, he attracts females newt, helping
larvae also have powerful tails for with an elaborate courtship dance. it to hide from
swimming, but they do not have legs. predators.
These develop as the larvae grow Adult smooth newts look quite
in the pond, where they feed on different on land than in the water.
invertebrates and crustaceans. Sometimes, they can be mistaken for
lizards. However, newts move much
By summer’s end, they have usually more slowly than the fast-moving
metamorphosed (transformed) into lizards. Lizards have five toes on each
adults. During the transformation, front foot, with small claws and scaly
the newts lose their gills and develop skin. Smooth newts have only four
lungs for life on the land. However, toes, with no claws and softer skin
the larvae that hatch late in summer that lacks any scales.
spend winter in the pond and
become adults the following spring.

Close relatives
Smooth newts belong to a family
of about a dozen newts that are
widespread in Europe, North Africa,
and western Asia. Palmate and alpine
newts live on hills and mountains,
which are littered with tiny lakes
where they can breed. Smooth newts
are often mistaken for palmate

343

SNAKES

There are around 3,000 different different snake species in the world, and they
species of snakes, making up are divided into eighteen families. The largest
around 40 percent of all reptiles. family, Colubridae, includes over 1,500 species.
Snakes are unusual because they The most obvious feature of a snake is its lack
lack limbs, but they manage to of limbs. However, snakes still manage to move
move around with ease. Snakes and capture prey with deadly efficiency.
are some of the most efficient
predators on the planet. Snakes are a successful group of reptiles. They
live in almost every habitat on Earth except the
Along with lizards and worm-lizards, polar regions and the ocean depths. They live in
snakes forests, grasslands, deserts, freshwater lakes and
form one of the three main groups of reptiles. rivers, and in the oceans. Some spend their lives
The other two groups are crocodilians, and
turtles and tortoises. There are around 3,000 The garter snake is a common sight in gardens
and parks across the United States. Indeed,
it is the most widely distributed reptile in North

344

in trees, while others live under the ground. Fact File
Snakes are most abundant in hot, tropical, or
SNAKES
subtropical parts of the world. Southeast Asia, Order: Squamata
Central and South America, and Australia have Suborder: Serpentes
many snakes. In cool, temperate places snakes Families: 18 families, with 2,900 species:
are active only during the summer. They pass Acrochordidae (file snakes); Aniliidae and
the cold winter months in the sleeplike state of Cylindrophiidae (pipe snakes); Anomalepidae
hibernation. There are no snakes in Antarctica. (dwarf blind snakes); Anomochilidae (dwarf
Snakes have also failed to reach and colonize pipe snakes); Atractaspididae (stiletto
many remote islands, including New Zealand. snakes); Boidae and Bolyeriidae (boas);
Colubridae (typical snakes); Elapidae
Senses and Feeding (cobras); Leptotyphlopidae (thread snakes);
Snakes sense the world in a different way to Loxocemidae and Xenopeltidae (sunbeam
people. Most have poor eyesight and can only snakes); Pythonidae (pythons); Tropidophiidae
see moving objects. Their hearing is also poor, (dwarf boas); Typhlopidae (blind snakes);
but they can hear some sounds. They can also Uropeltidae (shield-tailed snakes); Viperidae
pick up vibrations passing through the ground. (vipers and pit vipers)

Snakes have a keen sense of smell. The forked Where do they live?: Almost every continent
tongue of a snake flickers out to collect scent apart from Antarctica
molecules floating in the air. The tongue then
touches two tiny pits in the roof of its mouth. Equator
Called the Jacobson’s organ, these pits can
identify scents. Boas, pit vipers, and pythons Habitat: Varies, but includes deserts, forest,
have an extra sense—two small pits on their grasslands, and the open ocean
snout that detect the body heat of warm prey. Size: 3 in. (8 cm) to 23 ft. (7 m)
This super-sense allows them to pinpoint the Appearance: Legless reptiles with an obvious
position of prey in total darkness. head and a long, often slender, body and tail.
Mostly dull colors with more striking markings
Depending on the size and species, snakes Diet: Invertebrates, amphibians, reptiles, birds,
prey on animals from the size of ants up to and small mammals
antelopes. They use various methods to tackle Breeding: Some snakes lays eggs; others give
their prey. Some snakes simply grab the victim birth to live young
in their jaws and swallow it. Snakes called Life span: Not known
constrictors coil their body around the prey Status: Varies depending on species
and squeeze it to death. Cobras, colubrids,
and vipers use venom to kill their victims. 345

SNAKES

Poison glands in their head are linked to two Moving Along
long teeth called fangs, which inject the prey Despite their lack of legs, snakes manage to
with venom when the snakes strikes. Snakes move about effectively. When moving over the
have flexible jaws. This allows them to open ground, most snakes flex their body to form a
their mouth very wide to swallow large prey. series of S-shaped curves. The underside of each

Size, shape, and color

Snakes vary in size, shape, and color, and Many snakes are dull and marked with
they have different patterns on the body. blotches, bands, or stripes. This provides
At just 3 inches in length, blind snakes are camouflage, helping the snake blend in
some of the smallest snakes. They are so with its surroundings. A few snakes are
thin that they would fit inside a pencil if brightly colored, with bands of black,
the lead was removed. Boas and pythons white, red, or yellow. These so-called
are the largest snakes and grow to 33 feet. “warning colors” tell potential enemies
Some snakes, especially those that climb that the snakes are poisonous. A few
trees, are long and slender. Others, such non-poisonous snakes have the same
as burrowing snakes, are squat with a colors, which fool their enemies into
short tail. Still others have bodies that leaving them alone. One example is the
are adapted for swimming in the oceans milk snake (below), which has the same
or tunneling through loose sand. coloration as the poisonous coral snake.

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curve pushes against the ground. As the snake SNAKES
moves forward, more scales push against the
same points on the ground. This produces a DID YOU KNOW?
smooth, flowing movement. A similar technique
is used when swimming. Some snakes have large scales
on their snout or that stick out
Large, heavy snakes such as boas and pythons over their eyes. These species
move in a straight line like a caterpillar. The are often called horned snakes.
snake hooks the edges of its lower scales against Saw-scaled vipers and horned
uneven ground to pull its body along. When vipers have ridged scales that
moving through a narrow tunnel, the snake they can use to produce sound.
contracts its body into tight loops that press
against the tunnel. It then reaches forward with 4
its head and neck, anchors itself, and pulls up
the rest of its body. It uses a similar technique to
climb trees. Sidewinders use a sideways looping
motion to move over loose sand.

These 1
illustrations 2
show four species
of snake: the sand
snake (1); the
common death
adder (2); the
southern hognose
(3); and the Indian
cobra in threat
pose (4).

3

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SNAKES

Breeding and Young Some snakes reproduce by laying eggs, which
The breeding habits of snakes vary according to they guard until they hatch. In other snake
species. They are also linked to habitat. In the species, the eggs develop inside the female’s
tropics, snakes breed at any time of year. In dry body, and she gives birth to live young that
areas, breeding often coincides with the rainy resemble miniature versions of the adult snakes.
season, when food is plentiful. In temperate
(mild) areas, snakes often breed in spring as Skin and Scales
soon as they emerge from hibernation. Like all reptiles, snakes are covered with scales.
The shape, size, and texture of these scales
The green tree python lives in the humid rain varies on different parts of the body and also
forests of Indonesia, Papua New Guinea, and according to species. Some species of snakes
northern Australia. It spends all its life in the trees, have ridged scales that help them climb trees
where it hunts small mammals such as rodents. or slither over the ground.

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SNAKES

The beauty rat snake is equally at home on the Inside snakes
ground or climbing trees. These lithe snakes can
reach lengths of up to 8 feet or more. Like all other reptiles, snakes are
vertebrates. This means they have a
Snakes shed their skin as they grow. Called bony inner skeleton, which includes
sloughing, this allows worn or damaged skin a skull and backbone. However, the
to be replaced and also helps the snake get rid lack of limbs and long, slender shape
of parasites (animals living on them). Only means that the body of a snake is a
the outer layer of epidermis (skin) is shed. bit different than most other reptiles.
Even the skin over the eyes is shed. A snake The vital organs are elongated to fit
that has shed its skin has particularly bright inside the body. Twin organs such as
markings. kidneys are arranged one behind the
other, rather than side by side as in
DID YOU KNOW? most animals. Most snakes have only
one working lung. The stomach is a
Some snakes feed on many kinds long tube taking up about one third
of different prey. Others specialize of the body. The intestines are not as
in capturing just one type of food, coiled up as in most animals.
such as birds’ eggs or rodents.
Young snakes often feed on different Heart
types of prey than the adults. They
move on to adult food when they Liver Kidney
reach a certain size.
Right lung Small intestine
Kidney

Stomach

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