According to Jack Hanna's Monkeys on the Interstate, a bear captured in Sanford, Florida was thought to have been the offspring of an escaped female Asian black bear and a male American black bear. Hybrids Ī possible American black bear- grizzly bear hybrid in the Yukon Territory, CanadaĪmerican black bears are reproductively compatible with several other bear species and occasionally produce hybrid offspring. After these prehistoric ursids became extinct during the last glacial period 10,000 years ago, American black bears were probably the only bear present in much of North America until the migration of brown bears to the rest of the continent.
However, both Arctodus and Tremarctos had survived several other, previous ice ages.
The American black bear's generalist behavior allowed it to exploit a wider variety of foods and has been given as a reason why, of these three genera, it alone survived climate and vegetative changes through the last Ice Age while the other, more specialized North American predators became extinct. The giant and lesser short-faced bears are thought to have been heavily carnivorous and the Florida spectacled bear more herbivorous, while the American black bears remained arboreal omnivores, like their Asian ancestors. 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. 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).
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