Black Bear Research Paper

Age and Sex Specific Seasonal Variations in Weight of Black Bears in Pakistan Bears Sanctuary

Little is known about the natural ecology and behavior of the Asiatic bear. Their diet varies depending on the season but, in common with most other bears, they are predominately herbivorous feeding on acorns, beech and other nuts as well as fruits and berries (Burnie,D. 2001). These bears spend around half of their time in the trees (Animal Diversity Web, July 2002) and construct platforms from branches and vegetation upon which they rest and feed (IUCN/SSC Bear and Polar Bear Specialist Group 1998). Females give birth to a litter of around 2 cubs in the safety of a winter den (Burnie, D. 2001). It often located within a tree hollow (IUCN/SSC Bear

At the northern extreme of its range, black bears may go into hibernation to survive the cold winters, although further to the south, bears migrate to warmer areas and thus avoid the need for hibernation (Animal Diversity Web July, 2002).

Hibernation

Denning and hibernation among black bears varies with latitude, from 5 to 7 months in northern Canada and Alaska to a week or so in northern Mexico. In areas with mild climates, bears may den for 3 to 4 months. However, some bears–particularly males–may remain active all or most of the winter, especially in mild or snow-free years. In one Massachusetts study, bears denned for about 4 months in 1980-81 and about 5 months in 1981-82. Several studies have concluded that den entry is dependent on fall food supply. Bears remain active longer when food is abundant, but enter the den earlier when food is scarce and fruitless searching results in a negative energy balance. However, gravid females may den as soon as they have accrued sufficient fat reserves for reproduction. The cumulative effects of increasing precipitation and lower temperatures may also play a role in the onset of denning. In Ontario, den entry dates ranged between September 20 to November 29 over a 5-year period,

They are excellent climbers and easily ascend trees by hooking or gripping them with their short, narrow claws. Cubs are capable of climbing as soon as they exit their natal den and readily climb in response to intrusion by strange bears or humans. The sow does not need to signal the cubs to climb, although she may readily do so. Cubs can easily climb to 100 feet or more. Black bears of all ages retain the climbing ability, although some old, large males may be reluctant to do so. The bears climb not only to escape a threat but also to rest, sleep, play, nurse, obtain food, or attain shelter (Bray and Barnes, 1967)

Good Swimmer

Black bears are also good swimmers and do not hesitate to enter water, whether to cross a waterway or to bathe or wallow. Two bears translocated to a small island in Newfoundland swam at least 0.6 mile through salt water to return to the capture site. Bears have also been seen swimming in Yellowstone Lake, Wyoming, “miles from shore”. In Massachusetts, bears regularly swim across the Connecticut River. (Bray and Barnes, 1967)

Diseases affect the health of black