The American black bear lived during the same period as the giant and lesser short-faced bears ( Arctodus simus and A. From the Holocene to the present, American black bears seem to have shrunk in size, but this has been disputed because of problems with dating these fossil specimens. The earliest American black bear fossils, which were located in Port Kennedy, Pennsylvania, greatly resemble the Asian species, though later specimens grew to sizes comparable to grizzly bears. The American black bear then split from the Asian black bear 4.08 mya. The ancestors of American black bears and Asian black bears diverged from sun bears 4.58 mya. vitabilis an "apparent precursor to modern black bears", it has also been placed within U. Although Wolverton and Lyman still consider U.
abstrusus may be the direct ancestor of the American black bear, which evolved in North America. Ī small primitive bear called Ursus abstrusus is the oldest known North American fossil member of the genus Ursus, dated to 4.95 mya. According to recent studies, the sun bear is also a relatively recent split from this lineage. American and Asian black bears are considered sister taxa and are more closely related to each other than to the other modern species of bears. Other characteristics such as diet, behavior, and habitat use are even less reliable because black bears and grizzly eat similar food, display similar behaviors, and occupy much of the same areas in some provinces and states.American black bear head, Cincinnati Zoo and Botanical Gardenĭespite living in North America, American black bears are not closely related to brown bears and polar bears genetic studies reveal that they split from a common ancestor 5.05 million years ago (mya). Even under the best of conditions you’ll find it’s nearly impossible to judge the size and weight of a bear in the wild. And just in case it isn’t difficult enough yet, try to imagine yourself distinguishing a juvenile dark-haired grizzly from an adult cinnamon-colored black bear in the dim light of an early morning or the long dusky shadows of an early fall evening. Then too, an adult male black bear will be much heavier and taller than a young grizzly.
An adult black bear, which can easily weigh 200-300 pounds, may not only weigh the same as a female grizzly but also be about the same height (3–3½ feet at the shoulder). A typical adult female grizzly weighs 200-350 pounds and adult males weigh 300-650 pounds. Most people tend to overestimate the weight and size of bears. Just like color, body size is also not a reliable indicator for identifying bears. Just like hair color, body size is unreliable for identification Black bears have a flatter, “Roman-nose” profile, larger ears, no visible shoulder hump and smaller claws. Grizzlies have a concave or “dished” facial profile, smaller ears and much larger claws than the black bear. The grizzly bear has a pronounced shoulder hump, which the black bear lacks. The best indicators are the size of the shoulders, the profile of the face and the length of the claws. Male black bears in Manitoba’s Riding Mountain National Park, for instance, can weigh up to 800 pounds in the fall, and female grizzly bears on Alberta’s Eastern Slopes can weigh as little as 250 pounds in the spring. Although grizzly bears are, on average, significantly larger than black bears, size is not a good indicator of which species is which. Grizzlies, likewise, may range in colour, from black to blond. It is also extremely important to know which species is which when you encounter a bear in your community or in the backcountry.īlack bears can be black, blue-black, dark brown, brown, cinnamon and even white. Why is this important? Every year, black bear hunters kill several grizzly bears by mistake, which can have dire consequences for local grizzly bear populations. Despite apparent differences in size and colour, grizzly vs black bear are often difficult to tell apart.
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