It's official: polar bears and grizzlies are interbreeding in the wild - and so are their offspring, according to DNA tests cited by TheStar.com. The offspring of a female polar-grizzly bear was discovered this month in Canada, proving that there are more of these hybrid animals in existence than the previously confirmed 17 located in zoos.

An Invuvialut hunter, David Kuptana, provided federal scientists with a sample of an unusual-looking bear that he shot during a hunting trip near Banks Island in Canada's Northwest Territories.

DNA tests have confirmed that the dead bear was the offspring of a female polar-grizzly mix and a male grizzly bear. The dead bear's DNA was compared to that of local polar bear and grizzly bear populations, and with that of another polar-grizzly hybrid, which was shot on Banks Island in 2006.

The 2006 specimen was the only other polar-grizzly bear ever confirmed outside of captivity. Scientists knew that these hybrid animals exist, but weren't sure whether they would be able to reproduce in the wild.

Polar-grizzly hybrids – sometimes called “grolar bears” - were first discovered when the two species, housed near each other in a zoo, got close enough to mate. Germany's Osnabruck Zoo, which is home to most of the 17 confirmed hybrid bears, is currently studying the mix.

Osnabruck's first polar-grizzly hybrid bears were born in 2004 after 25 years of cohabitation between the two species. It's unclear why the captive bears would suddenly start mating after so long, but the polar bear's changing habitat and subsequent moves further inland likely play a role in cases of wild interbreeding.

This rare breed is characterized by long necks and visible tails like their polar forebears, thick heads and shoulder humps from their grizzly forebears and long-toed feet partially insulated with hair which are a blend of traits from both species.

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