The many layers of the tropical rainforest provide a vast amount of resources to support animal life.

The tall trees and their interwoven branches, which dominate the canopy, host various types of epiphytes. Bats and birds, seeking nectar and pollen, are attracted to the flowers that bloom throughout the year.

Creatures that spend their lives either looking for prey or hiding for predators can find countless walkways and hideouts in the understory.

Leaves and thickets on the forest floor provide a rich source of food as well as refuge for tiny animals. A quietly flowing river, itself full of animal life, often winds through the floor of the forest.

Animals need specialized features to exploit the many opportunities that the rainforest provides.

For example, the three-told sloth depends upon its hooklike feet to allow it to spend its entire life hanging upside-down beneath the forest's branches.

The most prolific adaptations are styles of locomotion. Except for birds, the only vertebrates capable of true flight are the bats. However, frogs, snakes, lizards and mammals have evolved membranes that enable them to glide from one place to another.

Many primates, as well as some anteaters, pangolins and a porcupine, have prehensile tails that function as an additional limb. The primates use their tails for rapid and agile passage through the branches, while anteaters use them for holding on to a tree as they tear at an ant or termite nest with their claws.

Though the general characteristics of the tropical rainforest habitat are the same everywhere, the way in which its inhabitants have adapted to them varies from one continent to another. The monkeys of Africa and Southeast Asia are born without prehensile tails and, as a result, they move by running along the upper surface of the branches, or by swinging beneath them.

Many animals of the tropical rainforest demonstrate parallel evolution: two unrelated species develop to the point where they resemble one another because they are doing the same job, even though they occur in two distinct geographical regions.

Thus, the forest hog in Africa resembles the peccary of South America, while the pygmy hippopotamus of Africa is similar to the capybara of South America.

The drifting apart of the continents caused dislocation in the spread of certain types of animal, but others have evolved to take their place.

The present distribution of some rainforest animals reflects the past movements of the earth's crust; the presence of the tapir in both Southeast Asia and South America suggests that it originated somewhere in the African/Indian region, but reached South America when the continent was joined to Africa.

Because these animals have such specialized features, they have difficult adapting to changes in their environment. As human beings disturb the rainforests, the animals that live in them have difficulty coping with the new conditions.