|There are no gliding animals in the American tropics, the very place where prehensile tails are so common, and this distribution is even stranger when you consider that there are gliding squirrels in North America. The fact that prehensile tails are almost absent from the forests of Asia and Africa adds to the biogeographical mystery of these adaptations.|
Some people think different forest structure on
different continents accounts for this odd distribution of gliding animals and animals with prehensile tails. In general, African forests are
full of liana vines, and Asian forests lack liana vines. Tropical American forests have a moderate number of vines, and trees with
relatively fragile branches. Because of all the vines, animals can get around in African forests without special adaptations. But gliding
makes sense in the more open Asian forests, and prehensile tails are the way to go for the particular characteristics of American forests.
Orang utans are one of the many Asian primates which do not have prehensile tails, while a large percentage of American mammals do. Photo credit Corel Photo Clipart CD.
This idea certainly doesn't explain everything, and some people disagree with this theory. Why are there no prehensile tails in Asia? Primates such as gibbons and orang utans are unable to suspend themselves from a tail like howler monkeys, leaving both arms free to forage. Why don't some tropical American species glide? So far, nobody has a definite explanation.
[tropical forests] [mammals] [plants]
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