Many animals that live in the tropical rainforest understory have limbs that are designed for grasping and climbing.

Those species that spend most of their lives in the trees, such as the lorises, have the most specialized hands and feet.

Digital mobility in the loris's hand has been sacrificed in favor of a pincerlike grip. Special muscle fibers in the limbs, and an enhanced blood supply to these regions, enable the loris to grip on to things for long periods.

The slow loris, Nycticebus coucang, can hang by just one leg while it feeds.

Species that forage on the forest floor, such as the coati, have relatively unspecialized feet and hands.

Coatis have large, strong claws that enable them to secure a hold. These stout-bodied, short-legged mammals throw out their limbs as they race through the forest almost as if they were grappling irons.

The hands and feet of tree kangaroos show little modification from those of their grassland cousins. Tree kangaroos are almost equally at home on the ground and in the branches.

Their claws, however, are sharp and massive like crampons. The soles of their hands and feet are extremely rough, so that there is maximum fiction for gripping branches.

Because the animals of the understory must maneuver among tangled branches, they tend to be small and light.

Some, such as the tree kangaroo, and the larger cats, such as the jaguar, are restricted by their size to the thicker branches.


Few understory animals have prehensile tails, which are common among canopy-dwelling South American monkeys.

The loris has no tail at all.

Most species have tails that are often long, bushy and distinctively marked, such as those of the coati and several species of lemur.

They use their tails to balance themselves when they are sitting and eating, or when they are leaping from branch to branch.

The tree kangaroo and the aye-aye have tails almost one and a half times as long as their bodies.

The aye-aye wraps its tail around its body when it is asleep. It may do this in order to keep warm.