Childrens Illustrated Encyclopedia

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fifty MiLLiON yEARS before humans first lived on Earth, whales were

swimming in the oceans and rivers. Whales are among the most intelligent

of all creatures. they are also the largest living animals and among the

most gentle and graceful. Whales, dolphins, and porpoises make up

a fascinating group of mammals. they are warm-blooded, but unlike

seals, they have almost no fur; a thick layer of fatty blubber under the

skin keeps them warm. the whale group is divided into those with teeth

(toothed whales) and those without teeth (baleen whales). there are

dozens of different toothed whales, including the friendly bottle-nosed

dolphin and the ferocious orca, which eats almost anything in the sea.

toothless or baleen whales include the humpback and blue whales, which

feed by sieving small sea creatures, such as krill, through their teeth. Since

all whales and dolphins breathe air, they must swim to the surface

of the water regularly. Whales and dolphins swim by

moving their tails up and down; fish move their tails

from side to side. Whales have suffered greatly from

hunting by humans, and 9 kinds are on the

official lists of endangered species. today,

whaling is not allowed, in the hope

that the population of whales

will increase, although

some countries plan

to restart hunting

whales in 2016.

BOttLE-NOSEd

dOLphiN

Of all the animals

on Earth, the delightful, highly

intelligent bottle-nosed dolphin

is one of the friendliest and

most gentle toward humans.

thE SOciABLE dOLphiN

One of the most playful creatures in the

world is the dolphin. this sociable animal

lives in “superpods” of 1,000 to 5,000 animals.

they race through the waves and sometimes

can be seen scooting along in front of boats.

BLuE WhALE

the blue whale is the largest

animal alive today,

and it roams all

oceans. Blue whales

can live to 80 years

of age. the skin

on the blue whale’s

throat has many

grooves and expands

hugely as the whale feeds.

BLuE WhALE cALf

Newborn blue whale calves are

about 23 ft (7 m) long and weigh

about 6,000 to 8,000 lb (2,700-3,600 kg).

the baby whale, or calf, suckles milk from

its mother for about seven months before it

can start to use the baleen in its own mouth.

BREEdiNg

Like other mammals, a male and a female whale

come together to mate. Some whales, such as the

humpback, usually gives birth in warm seas, because

the newborn calf has very little blubber to keep it warm.

Most large whales produce just one calf every other year.

Baleen plates

for feeding

MOthER’S MiLk

A newborn whale must learn to breathe

air at the surface within a few minutes of

birth, or it will drown. it must also dive

down to suck milk from its mother’s

nipples. during the first few days the calf

learns how to suckle, then surface for air.

Dorsal (back)

fin

tEEth ANd BALEEN

toothed whales, such as the bottle-

nosed dolphin shown above, have

dozens of sharp teeth for gripping

fish and other slippery prey. Baleen

whales, such as the right whale

shown left, have comblike baleen

plates, also known as whalebone,

for sieving krill from the sea.

pORpOiSE

there are nine

different kinds of

porpoises. common,

or harbor, porpoises

such as the one shown here

are often seen in shallow water

close to harbors and beaches.

Whales and dolphins 566-

Blowhole (nostrils)

Calf returns to the

surface, breathes

out and rests.

Calf sucks and swallows milk

from its mother’s nipple

on her underside.

Calf holds its breath and

dives under its mother.

Calf lies by mother’s side on surface

of the water and breathes in air.

Tail fluke

Throat

pleats

US_566_Whales_Dolphins_1.indd 566 09/02/16 5:29 pm