Three-Toed Tree Sloths: Bradypodidae

Physical characteristics: The brown-throated three-toed sloth is named for the brown fur around its throat. Chest fur is also brown, and adult males have a patch of yellow or orange fur on their backs between their shoulder blades. On this patch are thin stripes of black fur. These tree sloths have dark fur "masks" around their eyes and the area where fur covers their ears.

Other fur color varies, depending on where the sloths live and mate. Just as human parents pass along traits like eye color to their children, sloth offspring inherit the coloring of their parents. Brown-throated sloths may have grayish brown or reddish brown hair. While The algae growing on the brown throated three-toed sloth's fur helps to keep it hidden in the trees. (Michael P. L. Fogden/Bruce Coleman Inc. Reproduced by permission.) some have patches of white hair in their fur, other sloths are almost completely white.

These sloths range in length from 1.5 to 2 feet (45 to 60 centimeters) and weigh from 7 to 11 pounds (3 to 5 kilograms). They have tiny tails and three digits with claws on each of their four feet.

Geographic range: Brown-throated tree sloths live in Mexico, throughout Central America, and in parts of South America. They are found in Argentina, Bolivia, Brazil, Colombia, Costa Rica, Ecuador, El Salvador, Honduras, Nicaragua, Panama, and Paraguay.

Habitat: Brown-throated sloths adapt to a variety of habitats. They live in rainforests, evergreen forests, parks, and pastures. They may spend up to three days in a tree before moving to another tree.

Diet: Since people frequently saw brown-throated sloths in Cecropia (sih-KROPE-ee-uh) trees, it was thought that sloths only fed on these trees. However, the tree-toed sloths eat leaves and twigs from up to thirty different species of trees. Since the sloth learns feeding habits from its mother, it prefers to eat from the same type of tree that its mother does.

Behavior and reproduction: Three-toed sloths are also known as ai by the Guarani people of South America. The name comes from the noise made when sloths are in trouble—they make a whistling sound and hiss.

Brown-throated sloths are solitary except while they're breeding. Once they mate, the male leaves. The female gives birth in five to six months. The female typically has one young. However, there have been a few cases of twin births. At birth, a sloth weighs from 0.4 to 0.6 pounds (0.2 to 0.25 kilograms).

The mother sloth carries her baby on her stomach. The offspring nurses for about six weeks. After that, it feeds itself by reaching up for food in the trees where its mother lives. The young sloth also learns its range, the area where it will travel to live and feed. By the age of six months, the sloth keeps one foot on its mother while reaching for food. After about nine months, the mother leaves her offspring to live on its own.

Brown-throated three-toed sloths and people: Sloths are of interest to medical researchers because they heal quickly. The brown-throated sloths have also been hunted as food.

Conservation status: Brown-throated sloths are not threatened. ∎