North American Bear Program (sample photographs and notes)
All North American bears descended from Etruscan bear stock in Asia.
First to arrive in North America 2.5 million years ago was the black bear.
Brown bears made their way to North America 300,000 years ago by way of the Aleutian land bridge.
DNA evidence confirms the polar bear evolved from the brown bear 150,000 years ago.
There are grizzly bear hybrids, where a polar bear and grizzly have produced offspring.
In North America there are an estimated 750,000 black bears, 60,000 brown bears and 25,000 polar bears.
Read More First to arrive in North America 2.5 million years ago was the black bear.
Brown bears made their way to North America 300,000 years ago by way of the Aleutian land bridge.
DNA evidence confirms the polar bear evolved from the brown bear 150,000 years ago.
There are grizzly bear hybrids, where a polar bear and grizzly have produced offspring.
In North America there are an estimated 750,000 black bears, 60,000 brown bears and 25,000 polar bears.
Bears will mate in late spring through early summer but the embryo does not implant into the uterus wall until November. This delayed implantation will not allow embryo development unless the female has enough fat reserves. The development of the embryo is complete in January or February and the cubs are born. Polar bear mating and embryo implantation occurs a few months earlier than that of the black or brown bear. scottdavisphotos.com
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