Black bears (Ursus americanus) are the most abundant and widely distributed of the three species of North American bears. They have been recorded in all states except Hawaii. In Alaska, black bears occur over most of the forested areas of the state. They are not found on the Seward Peninsula, on the Yukon-Kuskokwim Delta, or north of the Brooks Range. They also are absent from some of the large islands of the Gulf of Alaska, notably Kodiak, Montague, Hinchinbrook and others, and from the Alaska Peninsula beyond the area of Lake Iliamma. In Southeast Alaska, black bears occupy most islands with the exceptions of Admiralty, Baranof, Chichagof, and Kruzof. These are inhabited by brown bears. Both species occur on the southeastern mainland. Black bears are most often associated with forests, but depending on the season of the year, they may be found from sea level to alpine areas.
General description: Black bears are the smallest of the North American bears. Adult bears stand about 29 inches (.73 m) at the shoulders and measure about 60 inches (1.5 m) from nose to tail. The tail is about two inches long. Males are larger than females. An average adult male in spring weighs about 180-200 pounds (81.8 to 90.9 kg). They are considerably lighter when they emerge from winter dormancy and may be 20 percent heavier in the fall when they are fat.
The color of this bear over its entire range varies from jet black to white. A very rare white or creamy phase occurs on KermodeIsland and vicinity in British Columbia. Three colors are common in Alaska. Black is the most often encountered color, but brown or cinnamon bears are often seen in southcentral Alaska and the southeastern mainland. The rare blue (glacier) phase may be seen in the Yakutat area and has been reported in other parts of Southeast Alaska. Only the black color phase is seen on the islands of Southeast. Black bears may have a patch of white hair on the fronts of their chests.
Black bears are most easily distinguished from brown bears by their straight facial profile and their claws which are sharply curved and seldom over 1½ inches in length. Positive identification can be made by measuring the upper rear molar which is never more than 1¼ inches long in the black bear and is never less than that in a brown bear. Black bears have adequate senses of sight and hearing. They do have, however, an outstanding sense of smell.
Life history: Mating can take place anytime from June through July. Apart from that time, black bears are usually solitary, except for sows with cubs. The fertilized egg will not implant in the uterus until the fall. The cubs are born in their dens following a gestation period of about seven months. The cubs are born blind, nearly hairless, and weigh under a pound (.4 kg). Upon emerging from the den in May, they may weigh about 5 pounds (2.3 kg) and are covered with fine wooly hair. They are able to follow their mothers quite well. One to four cubs may be born, but two is most common. Cubs apparently remain with their mothers through the first winter following birth. Bears mature sexually at 3 to 6 years of age, depending upon their environment. In their more southern ranges they will breed every other year unless a litter is lost early during the first summer, then the sow will breed again that year. In more marginal environments such as northern Alaska, black bears keep their cubs with them an extra year and will breed every third year.
Food habits: Black bears are creatures of opportunity when it comes to food. There are, however, certain patterns of food-seeking which they follow. Upon emergence in the spring, freshly sprouted green vegetation is their main food item, but they will eat nearly anything they encounter. Winter-killed animals are readily eaten, and in some areas black bears have been found to be effective predators on newborn moose calves. As summer progresses, feeding shifts to salmon if they are available. In areas without salmon, bears rely primarily on vegetation throughout the year. Berries, especially blueberries, are an important late summer-fall food item. Ants, grubs, and other insects help to round out the black bear's diet. Male bears may occasionly prey on their own young.