Page 18 - Mammal (DK Eyewitness)

Mammal senses

One reason for the mammals’
success is their “good sense” - their
generally well-developed senses of
sight, hearing, smell, taste, and touch.
Each sense has been molded by
evolution to fit its owner’s way of life.
Good vision would be of little use to an
underground mammal like a mole (p. 56),
THE CAT’S WHISKERS
Or in this case, the mouse’s whiskers! so this creature has poor eyesight; but it
Whiskers are longer-than-normal hairs with has an extremely sensitive muzzle that
sensory cells embedded in the skin to detect
any movement. Most whiskers are on the face, combines touch and smell in order to find
but some mammals have them on their legs, food (chiefly earthworms that emerge from
feet, or back.
the walls of its burrow). We humans depend
on our sense of vision. It is estimated that four fifths of what the human brain
knows comes in via the eyes. So it is difficult for us to imagine the accuracy with
which a mammal with a good nose smells the world through scents and odors, or
how a bat hears its surroundings by echoed squeaks (p. 19). Yet, even though we
depend on our eyes so much, our vision is not tremendous -
other mammals, such as some species of squirrels, have
much sharper sight. On the plus side, however, the
primates (including humans and bush babies)
are the main mammalian group with Brain cavity
color vision. Most mammals see the
world in black and white.

SKULLFUL OF SENSES
This cutaway view of a baboon’s skull shows how a
mammal’s main senses are concentrated in the
head. Bony cavities protect the brain, the eyes, the
organs of smell, and the tasting tongue. The
mammalian brain is large in proportion to the Long, bushy tail
body, as it has to make sense of the mass of
information sent from the rest of the body. Nasal passage Roof of mouth

PRICKING UP THE EARS
Many mammals,
including dogs, have a
good sense of hearing
and can move their ears
in the direction of a
sound. This gives greater
accuracy in pinpointing
where the sound is
coming from.

HUNTING BY TOUCH
The platypus grubs about in rivers
and streams for food, and finds its
prey of water worms, insects, and FOOD-TESTING TONGUE
crayfish almost entirely by touch, This lion tests its food partly by
as its bill is extremely sensitive. THE WORLD IN SMELLS smell and partly by taste. But
A pig with a trained nose snuffles for truffles tongues not only taste, they do
- underground fungi that will be dug up by its other jobs. A mammal licking its
owner and sold as an expensive delicacy. lips is cleaning its face (pp. 44-47).

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