Genus & Species: Choloepus didactylus
Listed as Least Concern on the IUCN Red List.
Nicaragua to Peru and central Brazil.
Lowland and upland tropical forest; montane forests to 7,000 feet.
Almost entirely nocturnal.
Head and body length is 22 to 30 inches and weight is 9 to 19 lbs.
10 to 30 years in captivity.
Diet in the Wild: Leaves, tender twigs, fruit
Diet in the Zoo: Greens, “leaf-eater” biscuit, and vegetables, including raw and cooked sweet potato, yams, broccoli, and green beans.
Fur consists of long guard hairs and short underfur. The body fur coloration is grayish brown and the facial fur a lighter tan. The shoulders and the top of the head are the darkest. The coat often has a greenish cast, produced by alga growth on the fur. There are 2 digits on each forefoot and they are closely bound together with skin for their entire length. Each digit is armed with a large hook-like claw about 3 inches in length. The hind feet have 3 toes, each with its own claw. The forelegs are approximately equal in length to the hindlegs. No tail is present.
Gestation: Estimated 11.5 months.
Offspring: 1 young. Weight is 12 to 16 ounces.
Parental Care: The young sloth hooks its tiny claws into the long hair of the mother’s breast and abdomen where it clings while the mother climbs or rests. The young first hangs upside down at 20 to 25 days and regularly feeds away from the mother at 5 months.
- Ecology, Adaptations, Etc:
Almost their entire life is spent upside down in the canopy layer of trees including eating, sleeping, mating, and giving birth. Once per week they descend to the ground to defecate. Sloths bury their fecal waste which in turn fertilizes the tree upon which they have been feeding. Females tend to gather in groups but males are solitary. Home range is 5 to 7.5 acres. Unlike most mammals, the body temperature of the sloth varies depending on the temperature of their surroundings. Sloths of the genus Choloepus have the lowest and most variable body temperature of any mammal, ranging from 75°F to 91°F. Since they have very little muscle mass, sloths cannot shiver to produce heat and so are limited to warm climates. The hairs are grooved to encourage colonization by algae; the green algae color may benefit the sloth in providing camouflage. Sloths lack incisors and true canines. Their first premolars have a sharp fang-like cusp that give the appearance of canines and enable the sloth to inflict a serious wound. The molars are peg-shaped for grinding. All teeth lack enamel and grow continuously. Sloths spend 15 to 18 hours of every 24 sleeping. The remainder of the time is spent eating and slowly digesting their meal (it may take up to 1 month) in a large compartmentalized stomach containing cellulose-digesting bacteria. They obtain water from their diet and by licking moisture off leaves. The metabolic rate is low – about 40 to 45% of a comparably sized terrestrial mammal.
Sloths are hunted by jaguars, harpy eagles, and humans.