Arboreal locomotion

The habitats pose numerous mechanical challenges to animals moving through them and lead to a variety of anatomical, behavioral and ecological consequences as well as variations throughout different species.

[1] Moving along narrow surfaces, such as a branch of a tree, can create special difficulties for animals who are not adapted to deal with balancing on small diameter substrates.

[3] Due to the height of many branches and the potentially disastrous consequences of a fall, balance is of primary importance to arboreal animals.

[1] Arboreal animals frequently have elongated limbs that help them cross gaps, reach fruit or other resources, test the firmness of support ahead, and in some cases, to brachiate.

In the spider monkey and crested gecko, the tip of the tail has either a bare patch or adhesive pad, which provides increased friction.

Dry adhesion is best typified by the specialized toes of geckos, which use van der Waals forces to adhere to many substrates, even glass.

To control descent, especially down large diameter branches, some arboreal animals such as squirrels have evolved highly mobile ankle joints that permit rotating the foot into a 'reversed' posture.

[citation needed] Brachiation is a specialized form of arboreal locomotion, used by primates to move very rapidly while hanging beneath branches.

Only a few species are brachiators, and all of these are primates; it is a major means of locomotion among spider monkeys and gibbons, and is occasionally used by female orangutans.

[citation needed] To bridge gaps between trees, many animals such as the flying squirrel have adapted membranes, such as patagia for gliding flight.

Some animals can slow their descent in the air using a method known as parachuting, such as Rhacophorus (a "flying frog" species) that has adapted toe membranes allowing it to fall more slowly after leaping from trees.

[15] The earliest known climbing tetrapod is the varanopid amniote Eoscansor from the Late Carboniferous (Pennsylvanian) of North America which is clearly specialised with adaptations for grasping, likely onto tree trunks.

[16] Suminia, a anomodont synapsid from Russia dating to the Late Permian, about 260 million years ago, was also likely a specialised climber.