Bats come in a variety of shapes and sizes. The largest bat, the Indonesian flying fox
(a megabat), may have wingspans of up to six feet (two meters), while the tiny bumblebee microbats of
Thailand weigh only 2g and would feel the same in your hand as a 10p piece!1.
A major misconception about bats is that they are blind, an idea that originated from the fact
that microbats have very small eyes. They orientate instead by listening to echoes as they bounce
off surrounding objects, a process called 'echolocation'.
Bats are not exactly renowned for their beauty. Some microbat species
have complex noseleaves, folds, or wrinkles on their muzzles, which are used to direct their
A Spear-nosed microbat
The ears range from small and round to large and pointed, and often have a cartilaginous
fold (tragus) present at the notch of the ear regions.3.
A Long-eared microbat (Plecotus auritus)
Megabats, on the other hand, have large and complex eyes - the expression "as blind as a
bat" does not apply to fruitbats! Notice how this megabat (Pteropus species) has a longer
muzzle than the microbats
shown above, giving it a truly fox-like appearance and the common name "flying fox".These fruitbats
also have very long and strong thumbs
with curved thumbnails like claws, which they use for climbing around in trees and gripping
..and his claw
Bat fingers have the same number of bones ours do, but they are proportionately much longer.
Look at your fingers and forearm; try to fold your fingers down against your arm, and
imagine your fingers extending past your elbow. But don't forget to leave your thumb
extending forward for gripping and climbing!
When bats extend their fingers, their wings are ready for flight. By shaping their 'hands'
they control their flight path. |
Morphological changes associated with the evolution
of flight have had a profound effect on the roosting habits of bats.
For example, the hind limbs of most bats have been rotated 90° from the position typical
to terrestrial mammals, such that the foot and its claw point backwards.
This makes hanging upside down possible.