The North American Black bear lives in temperate forests in Canada, Alaska and in patches over the United States and into Mexico. Estimated population of this North American bear is between 400,000 and 750,000.
Overview of the North American Black Bear
Black bears are most active at night and their diet consists of fruits, nuts, grass, insects, fish, rodents and carrion. It is classified as a carnivore; however, almost three quarters of its diet is plant matter. Current Taxonomy of the American Black bear is:
- Kingdom: Animalia
- Phylum: Chordata
- Class: Mammalia
- Order: Carnivora
- Family: Ursidae
- Genus: Ursus
- Species: U. americanus
While black bears generally forage for food alone, they often congregate around a large food source. Food availability partially determines their home range. A female black bear’s range is approximately 6.5 - 26sq km and a male black bear’s range is between 26 – 124sq km.
Female black bears reach sexually maturity between 3-5 months and mating occurs in the middle of summer. Males leave soon after mating and cubs are born at the end of winter. At birth, the cubs weigh between 240-330grams and leave the den at 5 weeks, thought they stay with their mother to learn foraging and climbing.
Black bears have short narrow claws compared with brown bears and their hind feet are also shorter. Tending to be lighter in weight than grizzlies and due to the design of their feet and claws, black bears are able to climb trees. It is thought that they do this primarily to avoid potential threats and dangers, but also for shelter, nursing, foraging and playing.
Cubs stay with their mother for up to 2 years and are driven away by aggressive males trying to court their mother when she is again ready to mate. Female black bears will mate every second year and have between 1-5 cubs.
The size of the adult black bear can vary considerably and can depend on the quality of food available, but adults generally grow to 1.3 – 1.8m (4.25 – 6ft) and weigh in at 100 – 270kg (220 – 594lb) and can live for 25 years.
Like other bear species, this North American bear goes into a ‘winter sleep’. Contrary to popular belief, bears don’t actually hibernate. They enter a state of ‘winter sleep’ in which their body temperature drops just a few degrees. Due to their large mass, bears can store energy reserves and go into winter sleep without the need to reduce their body temperature drastically. They will still wake up occasionally to eat or urinate.
Interesting North American Black Bear Facts
The North American black bear differs from other bears in its anatomical characteristics, particularly in comparison to brown/grizzly bears. Its narrow, shorter claws and generally lighter weight allows it to climb trees, which it is able to do from about 3 months of age. It also lacks the hump between the shoulder blades that brown bears have. Young brown/grizzly bears can climb trees but they lose this ability when they become sub-adults.
Research shows that while black bear attacks are seen more often than that of brown or grizzly attacks on humans, these attacks are less serious and so it is thought that black bears are less aggressive than brown/grizzly bears. The number of black bear attacks on humans is thought to be higher because black bears are willing to approach human inhabited areas to beg or steal food or go though the garbage.
Despite their name the black bear’s coloring can range from black to reddish brown, cinnamon and even pale tan and over short distances, it can run at speeds of up to 40km. Like many mammals, black bears tend to be more aggressive when threatened or when protecting cubs, and needless to say, climbing a tree to get away wont help much.
Resources and further reading: Aspects of Evolution and Adaptation in American Black Bears and Brown and Grizzly Bears of North America and American Black Bear.
Roberta Goli - Roberta has a Bachelor of Science Degree (Zoology), has worked with animals for over 10 years and enjoys writing short stories and flash ...
