Bats are mammals that have over time developed some
adaptations that make them stand out from other mammals.
First, they can fly; in fact they are the only true mammals
that can fly. Other mammals that look like they are flying, like the flying
squirrel are in fact gliding.
Bats differ. They are able to gain height because their
hands are incorporated into the wings; hence, their Order name is Chiroptera –
meaning hand wing.
Second, they can
echolocate, emitting ultrasonic sound that allows them to hunt and move around at
night.
Third, their sperm can be stored for many months and remain
fertile. Male bats are able to store sperm for long periods before mating. The
female bat is able to store the sperm in her uterus over the winter, ready for
ovulation in the spring, when the temperature warms up. This means bats
in temperate environments will mate during the autumn.
Fourth, we have the wings. An amazing part
of the bat body structure, the wing membrane stretches and encompasses the
tail, the body, hands, legs, and feet. The metacarpals and finger bones
(phalanges) are very elongated, though still keeping the basic structure of a
hand.
Fifth, not only can bats fly they
can also crawl and climb quite happily. This is due to a modification in the
upper leg bone of the femur (the hind leg). This bone is rotated 180° from the normal position,
meaning that the knee of a bat is
directed backwards instead of forwards.
Sixth, though bats look deceptively large and heavy when
flying, they are in fact quite lightweight to enable them to forage over long
distances. With their wings folded up majority of bat species are small enough
to fit into an adult’s hand.
Seventh, bats have a large stomach
and a short intestine. The stomach allows them to store as much food as
possible during peak feeding time, while the intestine allows them to digest
their food quickly, allowing them to keep their weight low when flying.
Eight, bats can hang upside down
when they are awake and when they are hibernating. A special locking mechanism
on their feet allows bats to grip and cling to a surface and stay locked whether
they are alert or relaxed.
Ninth, bats have adapted over time
to fit into many different ecosystems around the world. There are over 1,100
species of bats in the world. We can find 17 bats in the UK, 68 species of bats
in Trinidad and a whopping 175 bats in Indonesia. Here in the UK our bats are
insectivorous. However, other bats living elsewhere have specialised into
eating fruit, fish, nectar, pollen, blood, birds, small mammals, as well as
other bat species.
