LIFE CYCLE

Digging a burrow Puffin Today, some relatives of

When it was time to leave the nest, dinosaurs—birds—still live in dens
the young Oryctodromeus may have and burrows. Puffin burrows are very
found its own territory and moved into similar in shape to the burrows made
abandoned burrows, repairing them. by Oryctodromeus.
Alternatively, it could have dug its
own burrow from scratch.

Mating Gopher tortoise These tortoises help

Males may have perfected their out other wildlife. They make enormous
burrows—no female would want to burrows that provide homes for many
raise chicks in a shoddy home! A female different kinds of animals, including
chose a mate and moved in to lay her snakes, lizards, and rodents.

eggs. Together, they built a nest.

Oryctodromeus Safe from fire A burrow is usually

fossils have been safe during a forest fire because it’s
underground. The burrow retains
found in the burrows moisture and the temperature
stays low, even during a blaze.
where they lived
and died. 99

Colorful crests

By the time the young
pterosaur reached adulthood,
its brightly colored crest was
fully developed and may have
been displayed to attract
mates. Adults traveled long
distances, searching for
food and water.

Nest and eggs

Every year, the female Caiuajara
returned to the same place to nest
and lay her eggs. These eggs were
soft-shelled and too delicate to be
sat on—so the mother may have

kept them warm under a mound
of vegetation or buried them in sand.

As vegetation rots, it
produces heat—this
kept the eggs warm.

Fossil Pterosaur fossils Oasis An oasis is created

show that their bones in the desert when water
were hollow with thin seeps up to the surface.
walls, making them This makes a fertile area
very light. This helped for plants to grow and
pterosaurs fly. animals to drink and feed.
Fossils found near oases
100 tell us that Caiuajara
lived near them.

Caiuajara is Learning to fly
thought to have been
The chicks developed fast
an herbivore—it and were soon able to fly.
They tested out their wing
ate only plants. muscles by taking short
flights while staying
Vulnerable chicks close to home.

The young were helpless at See also
first and relied on their parents
for food. The large group, or Find out about other
colony, provided safety in prehistoric creatures in
numbers for the fragile chicks. “Dinosaurs through time”

Living together Today’s colonial (96–97).

birds, such as flamingos, nest and Pterosaur
breed in large groups. The discovery
of a site containing many Caiuajara At the time of the dinosaurs, flying reptiles
fossils, including eggs, babies, and called pterosaurs dominated the skies.
adults, suggests that they lived Caiuajara was a pterosaur from South America
in a similar way. who lived around 91 million years ago, during
a period called the Late Cretaceous.

101

Sea turtle See also The female green sea
turtle returns to land.
Green sea turtles live in warm Read about other sea
ocean waters and coastal areas. animals, such as the lemon
They spend many years swimming shark (88–89) and sockeye
in the open ocean until they are salmon (90–91), who swim
ready to breed. Turtles come to
the surface to breathe, and they to particular places
lay their eggs on land. Female to breed.
green sea turtles usually return
to the beach where they were Returning home
born to nest.
About two weeks after breeding,
The mother lays eggs the female leaves the water, usually
the size of ping-pong at night. She climbs ashore to find a
balls. Each nest of eggs
is called a clutch. suitable place to dig her nest.

Laying eggs in the sand thSeeawtauvretsle, swchawinchasyehneislpnestththheeedmiwrfeiacnttdioetnrh.oeifr

After laying up to 200 eggs in Breaking out
her nest, the mother covers
them with sand and returns to The temperature of the sand around
the water. She does this several the eggs determines whether the young
times. The eggs are incubated
(kept warm) for several weeks. will be male (cooler) or female
(warmer). The baby turtle uses a
Warm seas With flippers special tooth to break out of its shell.

for limbs, sea turtles are Protecting sea turtles
perfectly adapted to ocean
life. This green sea turtle is Sea turtles are endangered,
basking in the warm and and the survival of every
shallow coastal waters of baby is important. Turtle
the Gulf of Mexico. “head-start” programs
give babies like this olive
102 ridley a chance to grow
up in captivity before being
released back to the wild.

Mating in the shallows The lost years

The adults return to shallow waters, near their Once in the ocean, the surviving
nesting beaches, to find food and to breed. Males hatchlings seem to disappear. No one
will fight for a female by latching onto each other. knows exactly where they go. This
period of time is known as “the lost
Turtles often have several mates. years.” The turtles take at least 25 years
to mature before they start breeding.

To the ocean Helpless babies

Using their flippers as paddles, Baby sea turtles are very vulnerable
the baby turtles, called hatchlings, to predators. Animals including land
dig themselves out of the nest and crabs, crocodiles, dogs, and sharks
scramble for the ocean. At night, the
moonlight reflecting off the water prey on the eggs and hatchlings.

helps them find their way. Baby turtles are tiny—
they are only about
Red-eared slider Like other 2 in (5 cm) long.

freshwater turtles, the red-eared Sea kraits A type of
slider has clawed feet and a
retractable head and limbs. snake, sea kraits spend
The sea turtle has paddles most of their lives in
instead of claws, and its the ocean but return
body is streamlined for to nesting sites on land
life in the ocean. to lay their eggs—just
like sea turtles do.

103

Snake Wrestling

The king cobra is the world’s longest In the breeding season, males
venomous snake. It can grow more than fight over females. They raise
16 ft (5 m) in length and preys mainly on their heads high and then
other snakes. However, the king cobra has wrestle, trying to pin their rivals
a caring side too. Many snakes abandon to the ground. The defeated
their eggs immediately after laying them, snakes slink away.
but the king cobra builds a nest for its
eggs and guards them until they hatch.

Guarding the nest The king cobra raises its
hood to make itself look
The mother lies coiled on larger than it really is
the nest, guarding her eggs. and scare off predators.
If she feels threatened, she
Babies hatching opens her hood and gives a
low hiss. She also raises part
Just before hatching time, the of her body off the ground.
mother leaves the nest, leaving her When really big king cobras
babies to fend for themselves. In rear up, they can be as tall
four to six years’ time, the snakes as an adult human!
will be old enough to breed.
The venom of the
babies is as deadly
as the venom of
the adults.

104

Getting closer Python shivers Most python

When the winning male finds a mothers coil tightly around their
female who’s interested, he gently eggs to protect them. Pythons living
nudges her and moves over her. in cooler habitats also “shiver” their
She spreads her hood in response, muscles to produce heat and keep
the eggs warm.
and they mate.
Mom’s fierce fangs A female
Making a nest
rattlesnake gives birth to live young
Looping her body, the female and stays with her babies for about a
drags fallen leaves into a pile. She week or so. Any predator that comes
lays 20–50 eggs in the middle of too close risks a deadly bite from her
the pile, then covers them with venomous fangs.
more leaves to keep them warm.
Crocodile carrier Female Nile
See also
crocodiles help their eggs hatch
Read how the female sea by gently cracking them between their
turtle (102–103) buries her teeth. To keep the newborn crocs safe,
eggs too—but doesn’t stay they carry the babies to the water in
their mouths.
to guard them.

105

Breeding colors Lizard

In spring, as the weather Most reptiles lay eggs, but a few lizards
begins to get warmer, and some snakes give birth to fully formed
viviparous lizards come out babies. The viviparous lizard is unusual, in that
from hibernation. The males it can do both. This lizard produces live young
molt, shedding their skin in places where it would be too cold for eggs
in flakes, and develop their laid outside to survive. In warmer climates,
brighter breeding colors. it sometimes lays eggs.

Love bites Carrying young

During courtship, a male lizard The female adjusts her body
grips a female with his jaws. If temperature so that it’s just
she accepts him, the pair mate. right for her young to develop
However, if she is not interested, inside her. She basks in the sun
she bites him fiercely and to warm up and hides in the
he backs off.
shade to cool down.

Saltwater crocodile The Rubber boa Bearing live

biggest reptile eggs are laid by young is more common in
the saltwater crocodile, which is snakes than lizards. Roughly
the largest living reptile. Whether one-fifth of all snake species
the baby crocs that hatch are give birth rather than lay
male or female depends on the eggs. This includes the
temperature inside the nest rubber boa, which can have
when the eggs are incubating. up to eight babies at a time.

106

Live babies The babies are born inside
thin membranes that
In summer, two months or so break either during birth
after mating, the mother gives or soon afterward.

birth to 3–11 baby lizards.
In warmer places, the females

may produce eggs instead
of live young.

Off they go

The newborn lizards are
able to fend for themselves.
They soon scamper off to
live independently. Males by
the age of two, and females
by the age of three, will be

mature enough to breed.

Hibernation See also

Viviparous lizards in cooler Find out about another
regions hibernate in fall, cold-blooded animal that also
gives birth to live young—the
underground or in a sheltered
place such as a pile of logs. lemon shark (88–89).

In warmer climates, the lizards 107
remain active all year round.

Jackson’s chameleon

A chameleon is a type of lizard.
Most chameleons lay eggs, but
Jackson’s chameleon is one of
the few exceptions. The female
has up to 35 babies five to six
months after mating. The male
looks very striking, with three
horns on its head.

Penguin

Penguins are among the oddest birds that live on Earth.
For one thing, they cannot fly. Here, we follow the extraordinary
life cycle of emperor penguins in freezing Antarctica.

From the sea

When it is time to mate,
emperor penguins travel
from the sea about 56 miles
(90 km) inland until they
reach the icy breeding site.

Penguins bow their Mating The male places the egg on his
heads as a sign of feet and covers it with a skin
courtship before Penguins court and mate fold, called a brood pouch.
mating. around March to April.
The temperature is as low
as −104°F (−40°C).

Incubating

From June to July, the

mother gives her egg to

the father to look after,

while she returns to

Laying eggs the sea. The male keeps
the egg warm before it
Emperor penguins lay
their eggs between May The egg weighs hatches, a process
and June. Each female called incubation.
produces a single egg. about 1 lb (450 g).

108

Return to the sea See also Huddle From October to November,

Around January to February, To find out more about life in while the parents are hunting for food,
the young penguin is ready to extreme environments, the penguin chicks huddle together in
go to the sea for the first time. groups to keep warm.
When it is about three years old, see polar bears (124–125).
it will be ready to mate, and the
life cycle can begin again.

The parents take Molting Diving Emperor penguins are great
turns going to the
sea to hunt, By December, the chick swimmers and divers. They can stay
returning to feed starts to molt—it sheds underwater for up to 20 minutes
their chick. its down and starts to while hunting for food.
grow smooth waterproof
feathers. This means the
young penguin will soon
be ready to swim.

By September,
the chick can
stand on the ice
unsupported.

The penguin Feeding Enemies Emperor penguins have few
chick has a thin
layer of feathery The mother feeds her predators, but they have to watch out
down when it chick by bringing up food for leopard seals who might pounce
hatches. stored in her stomach. and attack them.
The food is like a paste
or oil by this stage. 109

Hatching

The mother returns from
the sea around August.
Sometimes the egg has
already hatched, but if not,
she takes the egg back from
the father. Once the egg
hatches, she keeps the chick
warm in her brood pouch.

See also In their first year, Leaving the nest
wandering albatrosses
Find out about the orangutan are brown with white It takes around nine months for
(130–131), who also takes a faces. They become the chick to be old enough to fly
long time to raise a small whiter with age. and be independent. By this time,
number of babies but can the parents are exhausted and
will not breed again until the
keep breeding for year after next.
many years.
Some albatrosses can still Albatrosses have
Caring for their chick age. a good sense of
breed at 70 years of smell, helping
The chick hatches with them track
white downy feathers and fishy meals.
grows quickly on a diet of
fish and squid. Mother and
father continue to share
their parental duties—
including fishing in the
seas around the island.

Building a nest

Mother and father collect mud and
grass to make a nest. They incubate
their single egg for 78 days, taking
turns sitting on the nest for two
to three weeks at a time.

110

Albatross Black-backed jackal A faithful

Some animals breed slowly but live long enough to breeding partnership works for
produce babies over many years. Wandering albatrosses black-backed jackals, just as it does
manage this in a lifelong partnership. Males and females for albatrosses—even their pups
come together to produce just one egg every two stick around to help their parents
years—but can remain as a couple for half a century. raise the next brood.

Albatrosses usually Becoming a parent Prairie vole Most male voles mate
pluck food from just
below the surface It takes a long time for an with several females, but male prairie
but sometimes albatross to grow up and voles have a single partner and play
plunge deeper. become a parent. Couples an equal role in raising their babies.
won’t pair up until both
partners are at least
10 years old.

Crested gibbon Daily grooming

between the male (left) and female
(right) helps strengthen the bond
between gibbons, which is
important for successfully
raising their babies.

Mating for life 111

Albatrosses are alone for
most of the year. But in
November, they come together
on remote grassy islands in the
cold Southern Ocean, where
they greet each other and mate.

Breeding Flying north

Once in Europe, the In spring, barn swallows leave Africa
swallows form breeding pairs. and travel thousands of miles to
The male courts a female with their breeding sites in Europe.
flying displays, singing, and by
showing his tail. If the female They feed while flying and drink by
is impressed, the pair will scooping up water as they fly low
mate. Pairs sometimes stay
together for life. over lakes and rivers.

The parents catch Nesting See also
insects for the chicks
and keep the nest clean. In the roof of a building, the pair Read about the big brown
make a cup-shaped nest out of bat (128–129), who also
Feeding chicks mud. The female lays three to uses buildings to breed.
seven eggs. Sometimes, the male
The eggs hatch after about two helps the female incubate the eggs.
weeks. The helpless chicks need
constant feeding. By the time Bar-headed goose This
they are around three weeks
old, they have grown feathers Asian goose has been
and are ready to fly. tracked flying at nearly
24,000 ft (7,300 m)
Bar-tailed godwit This bird over the Himalayan
Mountains—higher
holds the record for the longest than any other
nonstop bird flight. One godwit migrating bird.
traveled more than 6,800 miles
(11,000 km) on a continuous
journey as it migrated from
New Zealand to the Yellow
Sea in China.

112

Swallow Migration is tough:
many birds die through
Often seen gliding over fields as exhaustion, starvation,
they hunt for flying insects, barn swallows or in violent storms.
are swallows that breed among buildings.
After raising their chicks, most that live Winter in Africa
in the Northern Hemisphere fly off to
spend winter in warmer climates in When they reach southern Africa, the
the south. These barn swallows from swallows’ journey is over—for now. They
northern Europe, for example, spend the winter near wetland habitats,
migrate to southern Africa. where the air is abuzz with flying insects

to feast on.

Flying south Starlings Migrating

Barn swallows may raise two starlings often come
broods a year. In fall, after all their together to form a huge
chicks have learned to fly, and after cloud of birds that twists
growing a new set of feathers, the and turns in the air. Birds
swallows gather in large groups of prey find it harder to
and fly south. pick out individuals in
the swirling mass.
Arctic tern This record-holding
113
bird makes the longest migration
of all, from the Arctic to the
Antarctic and back again—a
total distance of 44,000 miles
(70,000 km). It rests on the way,
so it doesn’t match the godwit
for nonstop flight.

Ready for inspection The bowl-shaped
nest is usually built
When he is satisfied with his display,
the male calls female birds to inspect 6–10 ft (1–3 m)
his work. If a female likes the objects above the ground.
on show, she will mate with him.
Simple nest

After mating, the female
leaves and lays an egg in a
simple nest that she builds
in a tree. The mother raises
her single chick alone.

If the male leaves his bower, even
briefly, rival males may steal the

most attractive pieces.

Decorating the bower The bird arranges the objects
into piles according to their
On the lawn, the male bird places color, size, and shape.
objects he has collected from the
forest, such as flowers, leaves, berries,
fruits, beetle wing cases, and feathers.

Care to dance? Grebes Big red signal A male

choose partners by dancing frigate bird chooses a nesting
together on lakes and rivers. site and then inflates a bright
Great crested grebes present red pouch under his throat
weeds to each other as they to attract a female. He also
dance, while wiggling their shakes his outstretched
feet rapidly to scoot across wings and makes loud
the water together. gobbling noises. All in
all, he’s hard to miss!
114

Building the bower

The male Vogelkop bowerbird weaves
twigs and plant stems around a sapling

(young tree). When the bower is
finished, it looks like a little thatched

hut with an arched entrance.

Bowerbird

For male bowerbirds, finding a mate
involves a lot of hard work. They collect
brightly colored objects and display their
“treasures” beside structures, called
bowers, that are made from twigs. Each
bowerbird species builds a different kind
of bower, and the Vogelkop bowerbird
makes the most spectacular of all.

inBAouwsetrrabilriadsanadreNfoeuwndGounilnyea.

Creating a lawn See also

The bird clears the ground in front Find out how the emperor
of the entrance to the bower. He penguin (108–109) and the
then covers this area with a layer wandering albatross (110–111)
of moss, until it looks like a lawn. form longer partnerships to

look after their young.

Aerial displays To court Colorful character Striking

a female, a male peregrine colors and spiral tail
falcon performs spectacular feathers help a male
stunts in the air. This is to Wilson’s bird of paradise
show her that he is a skilled attract a mate. He calls to
enough flyer to catch food females and fans out his
for her, and for her chicks bright green chest feathers
when they hatch. to impress potential mates.

115

When it is born, the baby
dolphin is pushed to the
surface by its mother or
another female in the pod,
so it can breathe air.

Learning to swim Like all mammals, dolphins have
nipples and feed their babies with
A female dolphin is pregnant milk. The calf nurses for four to
for 12 months before giving five seconds at a time while the
birth. The mother teaches mother is swimming.
her newborn calf to stay
close by her. When she Dolphin
swims, her body creates
waves that propel the calf Though they live in water and look like fish,
through the water with her. dolphins are mammals that breathe air and
give birth to live young. Friendly bottlenose
dolphins live in groups, or pods, of up to 100
animals. Intelligent and sociable, dolphins do
everything together, including raising their
young in small nursery pods.

Swimming together Dolphins feed mostly on
small fish and squid. They
A male dolphin will use echoing sounds to find
either wait for a female their prey, a technique
to swim into his area, called echolocation.
or he will search for a
mate. The couple then
swim side by side, rubbing
their bellies together
while mating.

Dolphins can swim at speeds

of up to 19 mph (30 kph).

116

See also Dolphins leap out of the Sperm whale Adult sperm whales
water to get a better
Read about lemon sharks view of their prey. dive deep into the ocean to feed.
(88–89), who also start While some mothers go diving,
their lives in the protection others stay back to protect the
calves in the nursery pod.
of a nursery.

Females protect the Horse and foal Just as a dolphin calf
calves in the nursery
pod from predators can swim as soon as it’s born, so a
such as sharks. horse’s foal can stand and walk shortly
after birth. They are both examples
Nursery pod of precocious offspring.

Within each pod are small nursery
pods, made up of mothers and their
calves. Female dolphins even care for
the calves of other females. This is

called alloparenting.

Dolphin calves nurse for
up to two years and stay
with their mothers for
three to six years.

Fully grown Circle of defense Musk oxen protect

Dolphins use sound to communicate their young from predators, such as
with each other. Each dolphin has wolves, by forming a circle. They
its own signature whistle. This stand with their heads and horns
allows them to recognize, find, facing outward. The calves hide
and help each other. under their mothers in the center.

117

Kangaroo Females are usually
smaller and grayer
Red kangaroos are the largest than the males.
marsupials—mammals that carry
their young in a pouch. They can be Powerful male
up to 6 ft (1.8 m) in height. Kangaroos
use their strong legs and powerful The winning male may have fought
tails to hop across the scrublands off up to 10 competitors to win his
and deserts of Australia. chosen mate. He then checks if the
female is ready for mating by
Carrying joey smelling her urine (pee).

After mating, the female is See also
pregnant for only a month.
The newborn joey is just 1 inch Read about the sea horse
(2.5 cm) long—about the size of (92–93), who also has a
a lima bean. Shortly after birth, pouch—but it’s the dad that
the joey climbs up into its carries the offspring,
mother’s pouch.
as eggs.

The pouch
protects the
joey as it nurses
and grows.

Suckling

The mother’s pouch is
lined with mammary glands
that produce milk to feed her
young. The joey finds a nipple
and latches onto it—it can stay
attached for up to 70 days.

118

Wombat Unlike the kangaroo’s, the

wombat’s pouch faces its rear. This
means it doesn’t fill with soil when
the wombat is burrowing.

Group life Opossum The female Virginia

Kangaroos live in social groups. opossum gives birth to up to 21
Males compete for female babies, but she has only 13 nipples,
so not all survive. However, she can
partners by “boxing” with each nurse many babies at the same time!
other. They groom, kick, swat,
and wrestle to find out who is

the most powerful.

Kangaroos
can reach top
speeds of

44 mph
(71 kph).

Joey pops out! Koala After

When the joey is strong enough, it growing in the
starts to peek its head out of the pouch pouch for seven
to look at the world. Even after the months, a baby
joey is too big to live in the pouch, it koala rides on its
returns when it needs milk for several mother’s back for
more months. several more.

119

Linked-up Food web

world The connections between living
things are complicated. Many
No living thing can manage on its own: animals eat more than one
all plants and animals rely on other life kind of food. We call the links
to survive. Each animal needs to find between the various plants
food—whether that is leaves, meat, and animals a food web.
or even dung. Each plant can grow
properly only when nutrients from Plants are green
other organisms enrich the ground because they contain
around its roots. Plants and animals are chlorophyll, which
linked together in food chains that absorbs the sun’s
pass precious energy from one living energy.
thing to another.

Food chain Many insects, such
as locusts, feed on
Plants take in the energy from grass and other plants.
sunlight and change it into food They have mouthparts
so that they grow. Herbivores that can slice up
(plant eaters) eat the plants, then vegetation.
carnivores (meat eaters) eat
the herbivores. This series of Herbivores are
connections is called a food chain. called primary
consumers because
Plants are called producers they are the first
because they produce link in the food
food—they are at the chain.
start of the food chain.
Carnivores are called
secondary consumers
because they are the
second link in the
food chain.

120

Gazelles eat grass and Lions pounce on gazelles and
other plants. They have other animals and attack
grinding teeth for them with their powerful
grazing and a stomach jaws. They use their
that can digest even the sharp, stabbing teeth
toughest leaves. to cut through flesh.

Meerkats prey on
locusts, scorpions,
and other small
creatures.

Scorpions eat locusts
and other insects. They
use their pincers to
grab prey.

Cleaning up An eagle can
swoop down and
In nature, nothing is wasted. grab a meerkat in
Scavengers, such as vultures and its sharp claws.
hyenas, feed on dead animals.
Decomposers, such as worms and Vultures feed on the
dung beetles, break down plant remains of dead animals.
and animal remains. This releases
nutrients back into the soil and
helps plants grow.

Bacteria and worms break down
material, such as the remains of
dead animals after scavengers
have taken their pick.

121

Stallions fighting Zebra

Zebras of the southern Serengeti On the open grassy plains of the Serengeti in
mate and breed early in the year eastern Africa, zebras live in family groups, called
during the rainy season, when harems. A typical harem includes a stallion (male)
there is plenty of green grass to and several mares (females) with foals. The harems
eat. Stallions fight each other gather in huge herds made up of hundreds,
over who will mate with a mare. sometimes thousands, of zebras. Each year,
the herds migrate. They are following the
Stallions circle rains in search of fresh pastures.
each other, bite,
and kick out with
their sharp hooves.

Nuzzling Giving birth alone

Stallions and mares nuzzle each Mares are pregnant for a little
other before mating. The most over a year. This means that the
important, or dominant, mare in mares of the Serengeti have to
the harem breeds the most
often, and her foals rank travel long distances while
higher than the others. pregnant. To give birth, the
mother leaves the herd to hide
122
from predators, such as
cheetahs, lions, and hyenas.

Each zebra has a

unique stripe
pattern, like a bar code.

Moving on Oxpeckers These birds feed on

Every year, herds of zebras join parasites, including bloodsucking
wildebeests to travel a clockwise ticks, fleas, and biting flies, found
circuit around the Serengeti, on the skin of zebras. The bird’s
following the rains. By winter, alarm call warns the zebra when
they have returned south and a predator approaches.
are ready to give birth again.

Zebra foals Wildebeests Zebras and wildebeests

Most foals are born in January and Cheetahs hide in the are often found living in mixed herds,
February. The foals can stand soon long grass and prey and both follow the Serengeti
after they’re born, and they feed on their on zebra foals. migration— though a wildebeest’s
mother’s milk for up to a year. The young pregnancy is shorter than a zebra’s.
are vulnerable to attack—predators
kill about 50 percent of all zebra foals. Giraffes Giraffes are also found in

Oxpeckers like to the Serengeti. However, because
hitch rides on the giraffes cannot swim or cross rivers,
backs of zebras. they do not follow the migration. They
survive the dry season by nibbling on
the branches of tall acacia trees.

See also

Find out about sharks
(88–89), sea turtles
(102–103), and emperor
penguins (108–109), who also
follow seasonal migrations

to breed.

123

Hooded seal Female hooded seals Courtship

nurse for only about four days. Their In early summer, bears that are
milk has the highest fat content of any mature enough—from around
mammal, so pups grow rapidly and five to seven years old—start to
store fat (blubber) to keep warm. mate. Males follow the scent trail
left by female footprints. They
are together for only a few days.

Black rhino The milk of the black Preparing for birth The female digs a den,
or snow cave, in a
rhino is one of the lowest in fat After mating, the fertilized egg snowdrift. It will be
content of any mammal. Rhino doesn’t start developing in the only slightly larger
calves grow slowly, nursing for mother’s womb until fall. This than her body.
as long as two years. ensures that her cubs will be out
and about in springtime, when The mother polar bear
there’s more food. To prepare for lives off her fat stores
birth, she digs—and then snuggles for up to eight months.

down in—a snowy den.

Winter birth

Most female polar bears give birth to
twins in December and feed them with

fat-rich milk. The newborns are tiny,
weighing about 1pound (500 g). They
are blind and covered with short fur.

Pigeon The pigeon is one of the few

birds that produces a milklike liquid to
feed its young. The liquid is made in a
muscular pouch in the bird’s throat.

124

Growing up Hunting on the ice

Cubs grow fast on seal fat and Spring is a good time for hunting.
will stay with their mom for two Plenty of seal pups have been born,
and there is lots of sea ice, so polar
to three years. But when they
become independent, they bears can get close to their prey.
usually live alone and come Hungry mom can regain her
together only to mate. strength—and show her cubs
how to hunt and swim.
Polar bear
By early spring,
Polar bears live and breed on the sea ice the cubs are ready
that floats in the Arctic Ocean. These fierce to crawl out of
hunters are also strong swimmers and can the den.
stay in the freezing water for hours. Mother
polar bears are protective of their cubs and See also
will stay close by, watching over them as
they play together on the ice. Read about the emperor
penguin (108–109)—and how
Leaving the den it gives birth during the polar
winter too, but at the other
The mother’s milk is very high in fat.
It helps the cubs grow quickly. end of the world.

They stay snug in the den for a few
weeks until they are strong enough

to follow their mother to the
edge of the ice.

A polar bear’s fur

is see-through, and its skin is
black! The bear looks white

because it reflects light.

125

Naked mole rat Roots and tubers
provide all the food
No other mammal has a life cycle quite like and water that the
that of the naked mole rat. These burrowing colony needs.
rodents live in large groups, or colonies,
underground that are run kind of like bees re
in a beehive. One dominant female—the .
queen—produces all the babies.
thaOnn9e ca
Powerful queen ptiv0e0fbeambaiel s in juestpr1o1duyceeadrsmo Workers moving into
the queen’s chamber
The biggest, most aggressive huddle with babies to
member of the colony is the keep them warm.
queen. Her presence alone is
enough to stop other colony Lots of babies
members from breeding. She
can keep producing babies for The queen produces bigger litters than
16 years—a long time for such almost any other kind of mammal.
a small rodent. Every 12 to 19 weeks
she gives birth to up
to 28 babies.

A baby naked mole
rat leaving
the nest.

Moles Mole rats are Meerkat families

vegetarian rodents, while Meerkats live in
moles are worm-eating underground colonies,
burrowers. They are where a dominant pair
fiercely territorial and live produces the babies.
alone. Males and females Other colony members
come together only briefly help with babysitting.
to mate.

126

Mature males See also The worker in
front uses its
Unlike female workers, Read about ants, who are also teeth to dig, while
males stay fertile so they ruled by a dominant queen others behind it
can father babies. When males (78–79), and bats, another kick the loose
wander into the burrows from soil back.
other colonies, the queen selects small mammal that lives in big
her favorites and mates with them. groups (128–129). New colonies form
when tunnels get
Workers and soldiers The most dominant naked closed off and a new
mole rats are the ones who queen takes over on the
Babies grow up to become the win shoving matches inside other side.
workers of the colony. At first,
they dig tunnels and collect the tunnels.
food. As they get older, they
become soldiers, defending
the burrows from
intruders.

Termites These sociable

insects live in colonies
dominated by a breeding
queen and have workers
to look after the nest or
hive. Some termite species
live in mounds, which have
complex systems of tunnels.

127

Fully grown big brown bats Home to roost
have wingspans of roughly
13 in (33 cm ), and body By morning, bats have
lengths of up to 5 in (12 cm). returned to their roosts—
Females are slightly larger in tree hollows, caves, or
than males. buildings. As summer turns
to fall and days get colder, bats
See also fly less and spend more
time in their roosts.
Find out about polar bears
(124–125), who also
survive the winter by
hibernating.

Summer hunting First flight

The bats do most of their flying At three to four weeks old, the
on warm, dry summer nights— pups begin to take short flights.
when there are plenty of insects In order to catch flying insects
around. Some bats set out in the in the dark, they learn a
late afternoon, but most are technique called echolocation.
active two or three hours after It helps bats find their way
sunset. They will keep hunting using sounds.
through the night.
Echolocation Insect-eating bats
Vampire bat Vampire bats regurgitate
use echolocation to find their
(bring back up) blood they have digested food and avoid bumping into
from their prey to feed their pups. They things at night. The bat calls out
even do this to feed bats from other families. and then listens for an echo. If
there is an insect or tree in the
128 area, the echo lets the bat know
where it is.

Mating and hibernating

Adults mate in September. During winter, when
there are fewer insects around, the bats go into
hibernation. Their body temperature drops, and
they stop flying altogether. They lose weight
but are able to survive on their body fat.

Bat Maternity

Bats are the only mammals that can Although they mate
fly like a bird. However, instead of in the fall, females don’t
feathers, they have wings made of actually become pregnant
thin webbed skin. Some bats eat until after hibernation, in the
fruit, but most munch on insects— spring. The pregnant females
this includes the big brown bat, gather in maternity roosts. Their
found throughout North America. pregnancies last about 60 days.

Bats are helpful to Bat-sitting
farmers—they eat
insects that can harm From late April to early July,
female bats give birth to one
crops and animals. or two pups. Each baby bat is
small enough to curl around
your finger and is helpless for
the first few weeks of its life.
The females do all of the
parenting, and they even
babysit pups from
other families.

Clever moth There is a To save energy, the
mother hangs from her
particular species of moth feet when she roosts.
that can interfere with the The baby bats cling to
echolocation of bats. By
disrupting the sound system, it their mother.
saves itself from getting eaten!

129

130 Mother and baby

Orangutan Females are pregnant for around
eight months. Once the baby is born,
Orangutans are the largest tree-living great the mother bends tree branches to
ape. They use their long arms and huge make a sleeping platform and builds
hands to move easily through the tropical
forests of Indonesia. Their life cycle is slow a nest from leaves and sticks. The
compared to most other mammals. Mothers baby nurses for about two years
give birth once every six to eight years and and will stay with its mother for
have just four or five babies in their lifetime.
up to nine years.
Orangutans are Pairing up
more likely to Each night, the
breed when Orangutans pair up only briefly mother climbs up
there is plenty of to mate. Females are attracted to to her nest, with
fruit growing on the long calls of large, dominant her baby clinging
the trees. males, which can be heard about on tightly.
half a mile (1 km) away.
See also
Mature males have
Find out about the cheek pads called
wandering albatross flanges—these are
(110–111), who also cares an added attraction
for its young over a to females.

long period.

Becoming adults Family life

Young adults learn to climb Mothers keep their infants close
trees and become skilled by. Young orangutans make faces
at using twigs as tools. and signs to communicate. The
Orangutans are not as mother teaches her infant how to
sociable as other great find fruit and build a nest.
apes. Generally they
prefer to live alone. Orangutans eat mostly
fruit and young leaves.
They also feed on bark
and insects, including
ants and crickets.

Durian is the
orangutan’s
favorite
fruit.

Elephant Like orangutans, California condor These

female elephants take care of birds will delay laying eggs
their young for a long time— so that they can take care
up to eight years. At first, the of their existing young for
babies stay very close to longer—up to two years.
their mothers, learning Both parents help incubate
how to keep up with the the egg, feed the chick, and
herd. Once they are a little older, teach it how to fly. The chick
the young elephants learn how stays in the nest for most
to use their trunks and find food. of the first year. During the
second year, the parents
teach it how to hunt for food.

131

Humans Stone hand axes
were used for
through time chopping and
cutting.
If you are reading this, you must be a human. Humans are the
only species that has developed written language. It is one of
many things we do that make us unique, along with speaking
and making plans, for example. This is all thanks to millions of
years of gradual changes, or evolution.

Chimpanzees Stone tools
belong in our
family tree. Early humans began using their
hands to make simple stone tools

to chop up meat and plants.
It was the beginning of the time
period we call “the Stone Age.”

Mammals evolve Species split By this time, our
ancestors stood
The earliest mammals Human and chimpanzee upright and walked
were small creatures ancestors gradually began using only their
that emerged from reptile splitting into different species. legs.
ancestors. When a large
meteorite hit the Earth, While the ancestors of 3.5
it ended the reign of the chimpanzees lived in trees and mya
dinosaurs and left room
for mammals to evolve. used their arms and legs to
walk, our closest ancestors
First in the family started to live on the ground.

At this time, there lived an animal who

looked similar to the orangutans and

chimpanzees of today. It is considered to

be one of the first members of the family

65 tree that includes humans.
mya Our ancestors

began spending
more time on
the ground.

mya = million years ago Our entire family 10
kya = thousand years ago is called the mya
Hominidae,
or great apes.

12
mya

132

1.7 Fikree1ekm0ypa0awkainrgmh, ealnpdedprhoutmek1cy2aat nthsecmooskel,ves.
mya

2.5
mya

Eventually, people
lived in all parts of
the world except
Antarctica.

Getting cleverer Humans on the move Early settlers began
farming crops and
Stone tools helped early The first humans that were like us taming animals for
humans eat a wider variety of evolved in Africa. When some of them left, milk and wool.
food. The more skilled they they gradually crossed into new continents.
became at making tools, the Some areas had cold climates and strange
better they were at surviving.
Toolmaking required thinking, animals, such as the woolly mammoth.
so our smartest relatives became

the most successful
at staying alive.

Hunting and language

As our relatives became more
intelligent, they made tools to hunt
large animals. It was dangerous work,
so humans needed to plan and hunt

as a team. This required clever
thinking and a sharing of ideas, which

led us to develop language.

Early people hunted Settling down
woolly mammoths
with spears. Humans had to move around
regularly to hunt animals. Then
some people began farming in
one place. They built houses and
farms, eventually forming towns

and cities, trading with each
other, and slowly building our

modern world.

133

Infancy Childhood

During the first year, babies Children grow steadily and
grow quickly but are completely learn skills, such as running,
dependent on their parents for talking, and reading. They also
care, food, and protection. As learn to play with each other.
All children develop at
their muscles get stronger, different paces.
infants start to crawl and
eventually to walk. They may
also speak their first words.

A baby’s head is huge in

proportion to its body—so

that it can hold its

big brain!

Giving birth Growing up

The mother’s womb (uterus) contracts Teenagers, or adolescents, develop
to push the baby into the outside an adult shape and become more
world. Like all mammals, the baby is
fed with milk. Mothers usually give independent of their parents.
birth to one baby at a time, They start to be able to sexually
sometimes two (twins), reproduce, in a stage known as puberty.
or occasionally even more!

Fertilization A man and a Embryo Inside a female’s

woman come together to uterus, the fertilized egg
make a baby. One of the divides again and again to
female’s egg cells joins form an embryo, which is
with a male’s sperm a tiny human made of
cell, in a process called millions of cells. At eight
fertilization. This is how weeks old, the face, limbs,
all human life starts. and internal organs are all
in place.
134

Young adults

By around the age of 20, the body
is fully developed. Young people live
independently and may form close
sexual relationships. They may try
to have children.

Middle age

Between the ages of 40 and 60,
thinking and reasoning reaches
a peak, although signs of ageing
begin to appear. Some adults are
still having children and caring for
them. By later middle age, women

can no longer have babies.

Humans Old age

We are Homo sapiens—an In this final phase of the
intelligent species of mammal human life cycle, clear signs
that can live for more than 100 of ageing appear. These can
years. Parents care for their young include gray hair, wrinkled
for many years, longer than most
other mammals. Around the world, skin, poorer vision and
humans vary greatly—in terms of height, hearing, and stiffer joints.
weight, appearance, and more. This “slowing down” can be
lessened by regular exercise

and a healthy diet.

See also

Read about orangutans
(130–131)—a close relative
of humans—who also look
after their young for a long

period of time.

Pregnancy The baby 11–14 20–24 25–28 34–38
weeks weeks weeks weeks
develops inside the mother
for nine months until birth. 135
At 12 weeks, it begins to
grow nails. The baby can
recognize its mother’s voice at
24 weeks. A month later, the
baby’s hair starts to grow and
the eyelids open.

How we affect Pollution
life on Earth
As the world’s population increases,
We humans have a devastating impact on Earth. We we are using up more resources and
burn fossil fuels to power our homes and cities and creating more waste. Cars, factories,
create huge amounts of waste. We have been using and garbage pollute the air, land, and
Earth’s resources as if they were unlimited and putting
the lives of many species of animals and plants at risk. sea, harming animals and plants.
However, by changing our behavior, we can help Sea creatures eat plastic that ends up
protect the life cycles of other living things. in the oceans, harming themselves and

Problems . . . other animals that eat them.

Warming up

When we burn fossil fuels to
produce energy, we increase carbon

levels in the atmosphere.This
results in global warming—hotter
temperatures around the world,
which have a dramatic effect on

the environment.

136

. . . and solutions

Green energy

New technology allows
us to generate energy
without increasing global
warming and pollution.
Environmentally friendly—
or “green”—energy
sources include the wind,
the waves, and the sun.

Destroying habitats

We use around 30 percent of all land for food,
animal feed, and energy. The clearing of forests
to create more land is called deforestation, and

this has led to the loss of almost half of all
trees. It also threatens the homes of many

animal and plant species.

Hunting Wild farming

Hunters kill elephants for We can increase the variety of plants
their ivory, tigers for their and animals in an area by growing
skin and bones, and rhinos diverse crops and restoring habitats
for birds and pollinators—animals that
for their horns. This fertilize plants. This practice is called
practice, which kills wild farming.
millions of animals each
year, is causing many Cutting down on waste
species to die out, or
Recycling is the process of
go extinct. converting waste into new
materials. Coupled with
Species become extinct reusing objects instead
every day because of of throwing them away,
recycling helps preserve our
human activity. resources and protect the
environment.

137

Glossary

abdomen part of an animal’s conservation working to protect fertilization fusing (joining) of male

body that contains digestive and the natural world and female sex cells to produce
reproductive organs a new living thing
courtship animal behavior that
algae simple, plantlike living things fetus unborn mammal in the later
forms a bond between a male and a
that make their own food using energy female before mating stages of development
from sunlight
crust Earth’s hard, outermost layer fruit ripened female part of a flower
alloparenting care given to a young
deciduous plants that lose all their that contains seeds. Some fruits have a
animal by an adult that is not one of juicy wall to encourage animals to eat
its parents leaves at the same time, leaving the them and spread their seeds
plant bare. They grow new leaves the
anadromous used to describe fish, following year fungi type of living thing that absorbs

such as salmon, that migrate from salt decomposing rotting or decaying. food from living or dead matter
water to freshwater to spawn around it
The bodies of animals and plants
asexual reproduction reproduction decompose after they die galaxy very large group of stars

involving a single parent drupe fleshy fruit usually containing a and clouds of gas and dust

atmosphere layer of gases that hard stonelike seed. Coconuts, plums, germinate when a seed starts
cherries, and peaches are drupes
surrounds a planet to grow
egg fertilized female sex cell that
black dwarf dark, dead remains of a hermaphrodite living thing that has
develops into a new animal. Some eggs
white dwarf star that has cooled develop inside the mother’s body, both male and female reproductive
while others are laid. The eggs of birds parts. Earthworms are hermaphrodites
black hole region of space where and reptiles are enclosed by shells
hibernation sleep-like state that
gravity is so strong that not even light egg cell female sex cell
can escape from it. A black hole forms helps animals survive through winter
when a large star collapses into itself embryo early stage of development
host living thing that provides food
breeding producing offspring (baby of an animal or plant
for a parasite
organisms) by mating endangered at risk of becoming
igneous rock rock that forms when
chrysalis pupa stage of a butterfly extinct (dying out altogether)
magma cools underground or when
or moth erosion when rocks are worn down lava solidifies on the surface

clone plant or animal that is a replica and carried away by wind, running incubate to keep eggs warm until
water, or the moving ice of glaciers
of its parent. Clones are produced by they are ready to hatch
asexual reproduction evaporation when a liquid changes
larva young animal that is quite
cocoon case made of silk that to a gas
unlike its parents and which changes
protects an insect while it is pupating evergreen plant that sheds and into an adult by complete
metamorphosis (plural: larvae)
colony a number of living things of regrows its leaves all the time, so that
the plant is never without leaves lava hot, molten rock that erupts
the same kind that live closely together
exoskeleton hard, outer skeleton onto Earth’s surface from volcanoes
commensalism relationship where
surrounding the body of some animals litter a group of young born to an
one species benefits, but the other
neither benefits nor suffers harm animal at a single time

138

magma hot, molten rock that lies parasite living thing that lives on or sedimentary rock rock made

under Earth’s surface inside the body of another species, from sediment. Layers of sediment
called the host get squashed and cemented together
mammary glands body parts of until they form rock
parthenogenesis form of asexual
female mammals that make milk to seed capsule containing a plant
feed their young reproduction in which offspring develop
from unfertilized female sex cells. The embryo and a food store
mantle Earth’s soft interior, between young are clones of their parent
sex cell cell that is either male
its outer crust and inner core pod group of sea mammals, such as
(sperm cell) or female (egg cell)
mating coming together of a male dolphins or whales involved in reproduction

and female animal during sexual pollination transfer of pollen from sexual reproduction reproduction
reproduction
the male part of a flower to the female involving two parents
membrane thin barrier part of a flower. Pollination is essential
metamorphic rock rock that for sexual reproduction in flowers sperm male sex cell
spore single cell that is produced by
forms when existing rocks are polyp sea animal with a hollow
changed by heat and pressure to a fungus or plant that can grow into a
form new rocks cylindrical body and ring of tentacles new individual
around its mouth. A polyp is one of
metamorphosis dramatic change in the life cycle stages of corals supercontinent grouping of all or

body shape as a young animal develops predator animal that kills and eats most of Earth’s continents into a
into an adult single, vast landmass
other animals
migration seasonal journey by an tadpole larva of a frog or toad.
prey animal that is killed and eaten
animal to a new place, either to breed Tadpoles breathe through gills rather
or to feed by another animal than lungs, and they have long tails

molt how an animal sheds its outer proboscis long, flexible snout or tectonic plate one of the pieces

skin regularly in order to grow mouthpart. Butterflies and moths use that make up Earth’s rigid shell
a proboscis to suck nectar from
nebula giant cloud of gas and dust in flowers territory area claimed by an animal,

space (plural: nebulae) protostar young star that forms which it defends against rivals

nectar sugary liquid produced by when nuclear reactions occur in a hot, umbilical cord long cord that carries
spinning clump of gas and dust
flowers to attract pollinating animals blood between an unborn animal and
pupa resting stage in the life cycle its mother
nut hard, dry fruit containing a
of some insects, during which they uterus part of a female mammal’s
single seed develop from a larva to an adult
through a complete change in body body in which a baby develops before
nutrient material taken in by shape (metamorphosis) it is born (also called a womb)

a living thing to help it survive red giant huge, bright, reddish star weathering when rocks and
and grow
with a low surface temperature minerals are worn down into sediment
nymph young insect that looks
reproduction production of white dwarf dense, hot, glowing
similar to its parents but has no
wings and cannot reproduce. offspring (young). Reproduction core left behind when a medium-sized
Nymphs develop by incomplete can be sexual or asexual star dies
metamorphosis
sediment tiny pieces of rock, the 139
Pangaea supercontinent that existed
remains of living things, or chemical
about 320–200 million years ago, deposits that settle on the beds of
before breaking up lakes, rivers, and seas

Index

A birch trees 52 carnivorous plants 64–65 crested gibbons 111
birds 39, 45, 55, 97, 99, caterpillars 80, 81 crests 100
acorns 62, 63 century plants 91 Cretaceous period 97
albatrosses 110–111 108–115 ceratopsians 97 crocodiles 105, 106
alevin 90 birds of paradise, Wilson’s chameleons 107 cubs 124–125
algae 39, 43, 46, 87 chemical attraction 70 cytoplasm 46
alloparenting 117 115 chicks 101, 109, 110,
Allosaurus 96 birth 6 D
amber 27 112–113, 114, 115,
ammonites 29 bats 129 131 daddy longlegs spiders
amoebas 46–47 humans 134 childhood 134 76
amphibians 44, 94–95 naked mole rats 126 chimpanzees 132
anadromous migration 91 orangutans 130 chlorophyll 121 dancing 114
Andes 29 polar bears 124 chrysalises 80–81 dandelions 60–61
angelfish 73, 74 rivers 36 climate change 41, 45 Darwin’s frogs 95
animal seed dispersal 62, sea horses 93 clitellum 75 Darwin’s orchids 59
stars 12 clones 61, 84 death 6
67 zebras 122 clouds 32, 33
animals 6, 7, 68–131 black dwarfs 12 clown fish 73 carbon cycle 40
black lace-weaver spiders coconut octopuses 71 food chain 121
human impact 136, 137 coconut palms 56–57 fossils 26
life on Earth 42–45 85 cocoons 5, 74, 81 fungi 53
ants 58, 59, 78–79 black rhinos 124 colonies mayflies 83
Archaeopteryx 45 black widow spiders 85 ants 78–79 octopuses 70
Arctic Ocean 125 black-backed jackals 111 bats 128–129 salmon 90, 91
Arctic terns 113 bogs 37, 86 birds 101 spiders 76
argonaut octopuses 71 bottlenose dolphins corals 72–73, 86 stars 12
asexual reproduction 7, naked mole rats trees 55
116–117 126–27 decay 6, 40, 53, 63
46, 47, 60 bowerbirds 114–115 comets 6, 15, 17, 18–19 deciduous trees 63
asteroids 14, 15, 17, 45, bowers 114–115 commensalism 60–61 decomposers 121
boxing 119 condensation 32 deep sea habitats 87
97 Brachiosaurus 96 condors, California 131 defense 113, 117
Atlantic Ocean 23 bristles 64 cones 50, 54 deforestation 40, 57, 137
atmosphere 32, 40, 136 brood pouches 108, 109 conservation deltas 37
axolotls 95 Brunner’s stick mantises programs 102 dens 124
consumers 120 deserts 33
B 84 continents 22–23 devil’s fingers 52
burrows 98, 99, 126–127 coprolites 26, 27 Dicksonia 42
babies, human 134–135 butterflies 80–81 corals 72–73, 86 dinosauromorphs 96
bacteria 42, 46, 121 courtship dinosaurs 18, 26–27, 44,
ballooning 77 C bowerbirds 114–115
bar-headed geese 112 lizards 106 45, 96–99, 101
bar-tailed godwits 112 Caiuajaras 100–101 penguins 108 display
bats 128–129 California condors 131 polar birds 124
beaches 25, 37 calves, dolphin 116, 117 sea horses 92 birds 45, 112, 114–115
bees 51, 58–59, 65, 79, calving 38 swallows 112 dinosaurs 96
Cambrian explosion 42, mantises 84
137 pterosaurs 100
big bang 10, 11 43 diving 109
big-belly sea horses 93 carbon 40–41, 136
carbon dioxide 40, 41
140 carnivores 120

DNA 46, 47 evergreen trees 54–57 gas 10, 11, 12, 14 Homo sapiens 45, 135
dolphins 116–117 evolution 6, 44, 132, 133 gas giants 14, 15 honeybees 79
dormancy 63 exoskeletons 77, 82 gazelles 121 hooded seals 124
dormant volcanoes 31 expanding universe 11 geese, bar-headed 112 horses 117
dragonflies 82–83 extinct volcanoes 31 germination 50, 56, 64, 66 Hubble Space Telescope 11
drones 79 extinction 45, 96, 97, 137 giant Pacific octopuses 70, huddles 109
drupes 57 human impact 136–137
dung beetles 121 F 71 humans 45, 132–137
dust 12, 14–15, 18 giant sequoias 54–55 hunting 133, 137
dust devils 35 farming 133 giant tortoises 44 hurricanes 35
dwarf planets 14 feeding young Giant’s Causeway 31 hyenas 121
gibbons, crested 111 hyphae 52, 53
E birds 109, 110, 112 gills 53, 83, 86, 95
mammals 44, 116, 118, giraffes 123 I
eagles 120 glaciers 24, 38, 41
Earth 6, 11, 14, 15, 16, 119, 123, 124, 125 global warming 136 icebergs 38–39
ferns 7, 50 godwits, bar-tailed 112 Ichthyosaurus 44
20–47 fertilization 7, 50, 59, 62, gold specs jawfish 93 igneous rock 24, 25
earthquakes 23 Goldilocks zone 15 impact craters 18
earthworms 74–75 68, 72, 83, 90, 92, gopher tortoises 99 incomplete
echolocation 128–129 124, 134 gravity 10, 11, 12, 14, 15,
eclipses 16 fish 7, 39, 43, 73, 87, metamorphosis 82
eels, freshwater 91 88–93 16, 17, 18, 19 incubation 102, 108, 131
egg teeth 98, 102 flamingos 101 grebes, great crested 114 infancy 134
eggs 6, 7, 68 flight 100, 101, 110–113, green energy 41, 137 insects 43, 64–65, 78–85,
128–129 green sea turtles 102–103
amphibians 94–95 flippers 102, 103 greenhouse gases 40 121
birds 108–109, 110, 111, floodplains 37 grizzly bears 91 instars 82
flowers 44, 45, 51, 57–60, grooming 111
112, 114, 131 62, 65–67 groups, living in J
corals 72 fly agaric mushrooms
dinosaurs 98–99 52–53 ants 78–79 jackals, black-backed 111
earthworms 74, 75 foals 117, 122, 123 bats 126–127 Jackson’s chameleons 107
fish 88–90, 92–93 fog 33 birds 101 jawfish, gold specs 93
humans 134 food chains 120–121 dolphins 116, 117 joeys 118, 119
insects 66, 78–85 food webs 120 kangaroos 119 Jupiter 14
mammals 45, 124 forest fires 99 naked mole rats Jurassic period 96
octopuses 70, 71 forests 43, 53
plants 50, 54 fossil fuels 40, 41, 136 126–127 K
pterosaurs 100, 101 fossils 22, 26–27, 29, 83, zebras 122–123
reptiles 44, 102–107 99, 100, 101 growth 6 kangaroos 118–119
spiders 76–77 freshwater 86 king cobras 104–105
electrons 10 frigate birds 114 H king rag worms 74
elephants 131 frogs 94–95 koalas 119
embryos 134 fronds 56 habitat destruction 137 krill 39
emperor angelfish 73 fruit 51, 56, 57, 62, 67 hadrosaurs 97 Kuiper Belt 18, 19
emperor penguins fry 90, 93 hail 32, 35
fungi 7, 49, 52–53, 63 harems 122 L
108–109 fusion 14 herbivores 120
erosion 24, 29, 31, 36, 39 herds 122–123 ladybird spiders 77
eruptions, volcanic 30, 45, G hermaphrodites 75 lakes 86, 90
hibernation 106, 107, 128, larvae 72, 73, 78, 79, 80,
97 galaxies 11
euglossine bees 58 garden snails 74 129 83
evaporation 32, 33 Himalayas 28, 112
Everest, Mount 29 hives 79

141

lava 7, 24, 25, 30, 31 mayflies 83 fish 90 paper wasps 79
leaves 62–63 meanders 36 insects 78–79, 127 parasites 66, 123
Lemaître, Georges 11 meerkats 120, 126 mammals 126, 130, 131 parenting
lemon sharks 88–89 melting 39, 41, 136 pterosaurs 100
leopard seals 109 Mercury 14, 15 reptiles 102, 103, 104, amphibians 95
levees 37 Mesozoic era 96 birds 109, 110, 111, 112,
life metamorphic rock 24, 25 105
metamorphosis 80, 81, 82, neutrons 10 124
conditions for 15 Nile crocodiles 105 dinosaurs 98
on Earth 42–45, 136–137 83, 95 nipples 117, 118, 119 fish 92–93
life cycles 6–7 meteorites 18 nucleus 46, 47 humans 134–135
lightning 35 mice, house 60 nurseries 88, 116, 117 male 92, 93, 94,
lilies 59 microbes 42 nursery-web spiders 76
lions 121 Mid-Atlantic Ridge 23 nutrients 6, 53, 60, 64, 66, 108–109, 110
litters 88, 126 middle age 135 mammals 109, 111,
live young migrations 84, 85, 120
dolphins 116, 117 nuts 62 116–119, 123, 124,
mammals 44 humans 133 nuzzling 122 126, 129, 130–131
reptiles 105, 106, 107 lemon sharks 88 nymphs 82, 83, 85 pterosaurs 100, 101
sea horses 93 Monarch butterflies 81 penguins 38, 39, 108–109
sharks 88–89 Serengeti 122, 123 O peregrine falcons 115
lizards 106–107 sockeye salmon 91 pesticides 137
locusts 121 swallows 112, 113 oak trees 62–63 pheromones 84
lunar seas 16 milk 44, 116, 118, 123, oases 100 photosynthesis 40, 62
oceans 22, 23 pigeons 124
M 124, 125 pillow lavas 30
Milky Way 11 carbon cycle 40 pitcher plants 65
magma 24, 30, 31 mimic octopuses 71 fish 88–93 planetary nebulae 12, 13
mammals 7, 44, 45, mimosa 65 life on Earth 42, 43, 44 planets 6, 11, 14–15, 29
minerals 25, 26, 27 life in water 867 plankton 71, 90, 91
116–119, 122–131, mirror orchids 59 marine mountains 29 plants 6, 7, 48–67
132, 135 Mississippi River delta 37 rock cycle 25 carbon cycle 40
mammary glands 118 moles 126 seed dispersal 56 food chains 120, 121
mangroves 86, 88–89 molting 82, 85, 109 turtles 102–103 human impact 136, 137
Mars 14 monarch butterflies 80–81 water cycle 32–33 life on Earth 43, 44
marshes 37, 86 moon 16–17, 29 octopuses 70–71 water cycle 32
marsupials 118–119 moons 11, 14 old age 135 plastic waste 136
mass extinction 97 Morganucodon 44 olive ridley turtles 102 Plateosaurus 96
mating mosquitoes 83 oothecas 85 platypuses 45
amphibians 94 mosses 7, 43, 50 opossums 119 pods, dolphins 116, 117
birds 108, 111, 112, moths 81, 129 orangutans 130–131, 132 polar animals 87
114–115 mountains 6, 22, 28–29 orbicular batfish 89 polar bears 124–125, 136
dinosaurs 99 mudskippers 89 orbits 14–15, 17, 19 pollination 6, 7, 44, 50, 51,
earthworms 75 mushrooms 52–53 orchids 58–59 54, 56, 58–59, 64
fish 88, 92 musk oxen 117 Oryctodromeus 98–99 pollution 73, 136
insects 83, 84 mycelium 53 oxbow lakes 37 polyps 73, 86
mammals 116, 118, 122, oxpeckers 123 Pompeii 31
124–125, 127, 129, 130 N potter wasps 79
octopuses 70–71 P pouches
pterosaurs 100 naked mole rats 126–127 frigate birds 114
reptiles 102–103, 105, Neptune 14 Pacific Ocean 91 kangaroos 118, 119
106 nests paleontologists 26, 27 penguins 108, 109
spiders 76, 85 palm oil 57 sea horses 92, 93
birds 110, 112, 114, 131 Pangaea 22, 23 prairie voles 111
dinosaurs 99 praying mantises 84–85

142

pregnancy 135 roots 55, 57, 58, 60 Stegosaurus 26, 96 Vogelkop bowerbirds 115
delayed 124, 129 Rosetta space probe 18 strangler figs 66 volcanoes 7, 24, 30–31, 97
rubber boas 106 strawberry poison frogs voles, prairie 111
primates 45, 130–131 vultures 121
proboscis 81 S 94–95
producers 120 streams 33, 36, 86, 90 W
protons 10 salmon, sockeye 90–91 sublimation 19
protostars 12 salt pans 33 sun 12, 14–15, 16, 19 walking upright 132
pseudoscorpions 61 saltwater crocodiles 106 sunlight 120 wandering albatrosses
pterosaurs 100–101 sand tiger sharks 88 supercontinent 22
puberty 134 Saturn 14 swallows, barn 112–113 110–111
puffballs 53 sauropods 97 wasps 66, 79
puffins 99 scavengers 121 T water 15, 32–33, 37
pupae 78, 79, 80, 81, 83 scorpions 77, 121
pups 88–89, 124, 128, 129 sea anemones 73 tabular icebergs 38 life in 86–95
pygmy sea horses 93 sea horses 92–93 tadpoles 94, 95 water cycle 32–33
pythons 105 sea kraits 103 tails (comets) 18 water vapor 32
sea turtles 102–103 tectonic plates 22, 23, 28, waterfalls 36, 37, 86
Q seals 109, 124, 125 weathering 24, 29
seashore animals 87 30 webs 76
quarks 10 seaweed 43 teenagers 134 whales 87, 117
queens 78, 126 sediment 26, 37 termites 127 whistling 117
sedimentary rock 24, 25, Theia 16 white dwarfs 12
R thunderstorms 34, 35 wild farming 137
27 tides 17 wildebeests 123
radiation 10, 19 seeds 7, 44, 50–51, 54, toads, midwife 95 wind 34–35
rafflesias 66–67 tools 131, 132, 133 wind seed dispersal 61
rain 32, 33, 35, 36, 86 56–57, 59, 60–61, 62, tornadoes 34–35 wombats 119
rain forests 40, 43, 94–95, 64, 66–67 tortoises 44, 99 worms 74–75, 121
sensitive plants (mimosa) trace fossils 27
96 65 trees 43, 50–51, 54–57, Y
rattlesnakes 105 Serengeti 122–123
recycling 137 settlements 133 62–63 yolk sacs 90
red giants 13 seven-gilled sharks 43 Triassic period 96 young
red-eared sliders 103 sexual reproduction 7, 134 tributaries 36
reefs 72–73, 86 sharks 43, 88–89 Triceratops 97 calves 116, 117
remoras 61 silk 76–77, 81 chicks 101, 109, 110,
reproduction 6 slime mold 46 U
smolt 90, 91 112–113, 114, 115, 131
asexual 7, 46–47, 60 snails, garden 74 universe 10–11 cubs 124–125
human 134 snakes 103, 104–105, 106 Uranus 14 foals 117, 122, 123
plants 44, 50–51, 64, 91 snow 32, 33, 36, 38 urine 94, 118 fry 90, 93
sexual 7, 134 solar system 14–15 human babies 134–135
reptiles 44, 102–107, 132 solar wind 19 V joeys 118, 119
resources 136 space 6, 8–19, 29 pups 88–89, 124, 128,
respiration 41 spawning 91 V-shaped valleys 36
rhinos 124, 137 sperm 68, 72, 75, 94, 134 vampire bats 128 129
rhizomes 64 sperm whales 117 Venus 14, 15, 29
rivers 6, 24, 29, 33, 36–37, spiders 76–77, 85 Venus flytraps 64–65 Z
spores 7, 44, 46, 50, 52, 53 vertebrates 43
86, 90, 91 starlings 113 Victoria Falls 37 zebras 122–123
Rockies 22 stars 6, 10–11, 12–13 vines 66 zooplankton 91
rocks 6, 7, 24–25, 40 stegosaurs 97 viruses 46
rocky planets 14 viviparous lizards 106–107
roosts 128–129

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