Page 21 - Mammal (DK Eyewitness)

Flying mammals

M  can leap and bound. Some can swim and dive.
But only the bats can fly. Bats are the second most numerous group of
mammals, in terms of species (p. 9). They vary enormously in size, from
the tiny hog-nosed bat with a wingspan of 5 in (13 cm) to the large flying foxes
with a body the size of a small dog and outstretched wings 6 ft (2 m) across. The
bat’s flapping wings, unique among mammals, are made of thin sheets of
muscle and elastic fibers covered by skin. The bones of the arm and second to
fifth fingers support the wing; the “thumb” (first finger) is like a claw and
Pegasus -
used for crawling about, grooming, and, in some species, fighting and the legendary
holding food. The muscles that power the wings are the ones you use flying horse
to flap your arms, but proportionally many times stronger. Some bats
can fly at more than 50 kph (30 mph). Bats are also among the most sociable
of mammals. They roost together in their thousands in a cave or other
suitable site. Some species cooperate in the nightly search for food.
Males and females call to each other during the breeding season, and
baby bats jammed like pink jelly into nursery roosts squeak loudly
as the mothers return from hunting.

GLIDERS right
Bats are the only
mammals capable
of flight, but other
mammals such as
the marsupial
gliders and colugos
glide on the air
using a membrane
more like a
parachute than a
flapping wing.
5th finger BAT BABIES left
Clinging on to
4th finger their mother’s
2nd finger furry abdomen,
3rd finger bat babies suckle
milk, just like
1st finger (clawed “thumb”)
other mammals.
“SEEING” WITH SOUND
How bats echolocate
In fact bats hear in the
dark, using echolocation.
They send out high-
1. Ultrasonic squeaks sent out
pitched squeaks through
the mouth (1). The sound
2. Echoes bounce back off any object in path of squeaks
waves bounce off
anything in their path
and return to the bat’s
ears as echoes (2). The
bat’s brain computes the
pattern of echoes,
forming a “sound
3. After analyzing echoes bat homes in on prey
picture.” The bat then
homes in on the moth (3).
A VARIETY OF FACES
Among mammals, bats
have some of the most
FROM MOTHS TO BUDS TO BLOOD interesting faces.
Most bats are insectivores, eating moths, midges,
flies, and other nighttime flying creatures. The
fruit bat (shown here) feeds on fruit, buds, and
soft plant parts. The vampire bat feeds on blood.
Horse-shoe bat Leaf-nosed bat Bat with fringed tongue
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