American Black Bear Hybrids

American black bears are reproductive compatible with several other species of bears, and have often produce hybrid offspring. According to Jack Hanna's Monkeys on the Interstate, a bear captured in Sanford, Florida thought to be a offspring of escaped female Asian black bear and American black bear. In 1859, a black bear and a Eurasian brown bear were bred together in the London Zoological Gardens, but the three cubs did not reach maturity. In The Variation of Animals and Plants under Domestication Charles Darwin noted:

In the ninth-year report has found that the bears are seen in the Zoological Gardens to couple freely, but previously to 1848 most had rarely conceived In the Reports published since this date three species have produced young (hybrids in one case).

A huge black bear was shot in Autumn 1986 in Michigan, for which some thought was a hybrid of black bear and grizzly bear, due to its unusually large size and its proportionately larger braincase and skull. DNA tests failed to show whether it is a black bear or grizzly bear.