Ursus americanus Pallas
A medium-sized bear, black or brown in color; snout brownish in the black color phase; front claws slightly longer than the hind claws, curved, adapted for climbing; profile of face nearly straight, not "dished-in" as in the grizzly; fur long and rather coarse. Dental formula: 1 3/3, C 1/1, Pm 4/4, M 2/3 X 2 = 42. External measurements; total length, about 60 inches (1,500 mm.); tail, 5 inches (125 mm.); hind foot, 7 inches (175 mm.); height at shoulder about 25 inches (625 mm.). Weight usually from 200 to 300 pounds (100 to 150 kg.); occasionally as much as 500 pounds (225 kg.).
Black bears have been restricted by the inroads of "civilization" to the more remote, less accessible mountainous areas or to the nearly impenetrable thickets along watercourses. Only in places that have a low human population or an enlightened public have black bears been able to cope successfully with humans.
Largely creatures of woodland and forested areas, black bears are more at home on the ground than they are in the trees. They are expert climbers, however, and, especially when young, often seek refuge in trees. Ordinarily they are shy and retiring and seldom are seen. In the Guadalupe Mountains of western Texas, a group of us camped in a clearing through which bears passed each night, as evidenced by their tracks in the trails, yet in a period of 6 weeks none of us saw a bear. They appear to use definite travelways or runs, which habit is frequently taken advantage of by hunters. In spite of their large size and reputed clumsiness, bears are fleet- footed.
In the colder parts of their range, black bears "hole up" in a windfall, at the base of a tree, under a shelving rock, or in some other suitable site, and are inactive for a part of the winter. They do not exhibit the characteristics of true hibernation; their temperature does not drop markedly nor are the heart beat and respiratory rate materially reduced. Often the bears are nearly fully exposed to the winter weather during their prolonged sleep. They may awaken and become active during a warm spell in midwinter and return to the nest to sleep again when the temperature drops.
Their food is extremely varied as reflected by the crushing type of molar teeth. They are known to feed upon nest contents of Wild bees, carpenter ants, other insects; manzanita berries, coffee berries, Wild cherry, poison oak, apples, pine nuts, acorns, clover, grass, roots; fish, carrion and garbage about camps. Occasional animals become killers of livestock and young deer.
The one to four young (usually two) are born in January or February, while the mother is "hibernating" after a gestation period of 210 to 217 days. The breeding season is in June or July. At birth the young are blind, covered with a sparse growth of fine hair, and almost helpless. They weigh less than one pound (500 g.) and are about 6 inches (15 cm.) long. They grow rather slowly at first; their eyes open in about 6 weeks. By the time the mother is ready to leave her winter den they are strong enough to follow. The cubs remain with her until the fall of their second year when they venture forth on their own. By that time, the female is preparing for her next family. Normally, old females mate every other year, and young females do not mate until 2 years or more of age.
Bears have few enemies other than man. Their chief economic value is as a game animal. Their pelts have little value on the fur market, but they are prized as trophies.