Three-Toed Tree Sloths: Bradypodidae

The three-toed tree sloth family consists of four species, groups within the family that share similar characteristics. All species have eighteen peg-like teeth, slim bodies, long limbs, and tiny tails. Front limbs are longer than their back limbs.

Sloths' fur ranges in color from gray to brown. The brown-throated three-toed sloth has brown fur in its throat area and may also have white or red fur. The pale-throated sloth has dark fur on its back and lighter colored fur on its front. The maned sloth has long, black hair on its back and neck. The monk sloth has a tan face.

All species of sloths may have green in their fur. This is caused by algae (AL-jee), tiny water plants growing in sloths' hair. Algae are a food source, and sloths lick their fur when hungry. Sloths live in trees, and the green and brown in their fur helps them blend in with the trees and hide from predators, animals that hunt them for food.

The head and body length of three-toed tree sloths ranges from 15.8 to 30.3 inches (40 to 77 centimeters). Tail length ranges from 1.9 to 3.5 inches (4.7 to 9 centimeters). They weigh from 5.1 to 12.1 pounds (2.3 to 5.5 kilograms). The monk sloth is about 20 percent smaller than other sloth species.

Three-toed tree sloths have three long, hooked claws on the digits (toes) of each foot. Sloths use the claws measuring from 3.2 to 3.9 inches (8 to 10 centimeters) to hang upside down from tree branches. Sloths can see a great distance because sloths can turn their heads 270°. They can turn so far because sloths have eight or nine neck vertebrae (bone segments)—most mammals, including humans, have seven vertebrae.