Asian black bear
Along with sun bears, Asiatic black bears are the most typically used species in areas where bears are either used in performances or as pets. Asian black bears have an outstanding learning ability in captivity, and are among the most common species used in circus acts. According to Gary Brown:
American black bear
Generally, American black bears are largely crepuscular in foraging activity, though they may actively feed at any time. Up to 85% of the American black bear's diet consists of vegetation, though they tend to dig less than brown bears, eating far fewer roots, bulbs, corms and tubers than the latter species. When initially emerging from hibernation, they will seek to feed on carrion from winter-killed animals and newborn ungulates. As the spring temperature warms, American black bears seek new shoots of many plant species, especially new grasses, wetland plants and forbs. Young shoots and buds from trees and shrubs during the spring period are also especially important to American black bears emerging from hibernation, as they assist in rebuilding muscle and strengthening the skeleton and are often the only digestible foods available at that time. During summer, the diet largely comprises fruits, especially berries and soft masts such as buds and drupes. During the autumn hyperphagia, feeding becomes virtually the full-time task of American black bears. Hard masts become the most important part of the American black bear's diet in autumn and may even partially dictate the species' distribution. Favored masts such as hazelnuts, oak acorns and whitebark pine nuts may be consumed by the hundreds each day by a single American black bear during the fall. During the fall period, American black bears may also habitually raid the nut caches of tree squirrels. Also extremely important in fall are berries such as huckleberries and buffalo berries. American black bears living in areas near human settlements or around a considerable influx of recreational human activity often come to rely on foods inadvertently provided by humans, especially during summertime. These include refuse, birdseed, agricultural products and honey from apiaries.