These tremarctine bears evolved from bears that had emigrated from Asia to the Americas 7–8 mya. pristinus, respectively) and the Florida spectacled bear ( Tremarctos floridanus). 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. These bears are usually transient and do not stay in the area for long.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). Dispersing juvenile bears have been sighted in many counties in South Carolina. In addition, juvenile bears, especially the males, must disperse to find new home territories. Black bears will travel large distances to find adequate food sources. A shortage of natural food sources and lack of rainfall can cause home ranges to vary greatly. Typically male bear home ranges can be 18 to 160 square miles, while home ranges for females are smaller, around 6-19 square miles. Home range for bears must include den sites, food, water and cover for adults and young. In South Carolina, there are two resident populations of black bears, one in the mountains and upper piedmont and one in the coastal plain. As long as they can find adequate food sources and have suitable den sites, black bears can be found in a variety of habitats.īlack bears can be found throughout North America. Wetlands such as swamps and bays also provide good habitat. Typically, black bears require large expanses of forest dominated by a diversity of mast-producing hardwoods and shrubs intermixed with early successional vegetation such as blackberries, pokeberries, etc. Black bears reach sexual maturity by 3 years and obtain most of their growth by 5 years. The average life expectancy is 18 years in the wild. The largest black bear recorded in South Carolina was 609 pounds. However, when food is plentiful, older bears have been documented at weights above 400-500 pounds. An average adult male black bear can weigh between 150 - 350 pounds while the female averages between 100 -250 pounds. Male black bears are generally larger than females. Black bears are excellent climbers and good swimmers and can be found in a variety of habitats. They have good eyesight and an incredible sense of smell. The rump of a black bear is higher than the front shoulders, and they do not have the prominent shoulder hump of the Grizzly and Brown bears. They have a broad head with rounded ears set well back on the head. The most common color phase is black or dark brown with light brown snout. They are covered in a long thick fur that can vary in color. Black bears are the largest land mammals in South Carolina.
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