Fast Facts:

Sloth Bear

Social Structure & Behavior:

Little is known about the social organization and behavior of sloth bears. Some research indicates that they are generally solitary and maintain small territories. Studies in Nepal indicated that while the bears displayed some territory marking behaviors such as clawing trees, individual bears usually did not react aggressively to other bears entering their marked area. Sloth bears have several vocalizations that range from roars and howls to softer huffs and gurgles.

Although females may begin breeding at 4 years of age, they do not necessarily produce cubs in their first breeding season.  Mating usually occurs between May through July. However, in Sri Lanka, sloth bears have been known to mate at all times of the year.

Mating pairs form for only 1-2 days, and gestation will last between 6 and 7 months. The gestation period includes time for the process of delayed implantation. After a successful mating and egg fertilization, the developing embryo stops developing and is not implanted in the uterus until later. Once implanted, the embryo resumes development.

Cubs are usually born between late December and early January – during the dry season. A female sloth bear usually gives birth to 2 cubs. The tiny cubs typically weigh only 11-18 ounces each and are kept in dens for protection. As the cubs grown older and gain strength, female sloth bears often carry the cubs on their back. They cubs hang onto the female's long, shaggy fur. Cubs usually stay with their mother for 2-3 years.

Threats To Survival:

Sloth bear populations are declining due to habitat loss and poaching for the medicinal market.  Bear gall bladder has been used by traditional Chinese doctors since the sixth century A.D. and is believed to help cure fever, intestinal, liver, and cardiac-related illnesses. Bear gall bladders have sold for as much as $20 (U.S. dollars) per gram - that's more than the price of gold (WWF).

Unfortunately for bears, a compound, ursodeoxycholic acid (UDCA), found in the bile salts contained in their gall bladders, has proven medicinal properties. In fact, a synthesized form of UDCA is manufactured and prescribed in the United States to dissolve gallstones. The synthetic UDCA provides an alternative to killing bears for their gall bladder bile salts.

Unfortunately, many traditional medical practitioners in the Orient view these substitutes as inferior to the real thing, and often continue to seek out bile salts from bears instead of the synthesized version. In Asia, bear farms have been established where bile is extracted from live bears through a tube inserted in the gall bladder. However, some groups question the conditions under which many of the animals are kept. Others would argue that by continuing to supply the market with bear bile salts, these farms are only encouraging the demand for these products and discouraging the use of alternative forms.

Efforts to save the Sloth Bear:

The American Zoo and Aquarium Association's SSPs (Species Survival Plans) are special programs designed by a team of zoo and wildlife professionals to help sloth bears, and many other endangered species. The SSPs outline breeding plans, work to increase public awareness and education, help conduct research, and in some cases, organize programs to reintroduce captive-bred wildlife into secure habitats. The sloth bears at Rolling Hills Refuge are part of the SSP for the species.