A white bear with brown patches shot dead in northern Canada is the first grizzly-polar hybrid found in the wild, DNA tests have confirmed.
Canadian wildlife officials say it is the offspring of a male grizzly bear and a female polar bear.
There have long been stories of oddly coloured bears living in regions where the two territories overlap.
But until now, grizzly-polar hybrids, dubbed "grolar bears" or "pizzlies", have been found only in zoos.
The hybrid bear was shot last month by an American big game hunter on Banks Island, Northwest Territories, Canada.
His guide, Roger Kuptana, noticed the creature had the long claws and slightly humped back of a grizzly bear and thought it might be a hybrid.
The body was seized by officials, who sent a DNA sample for tests which confirmed its unusual origins.
"It's something we've all known was theoretically possible because their habitats overlap a little bit and their breeding seasons overlap a little bit," said Ian Stirling, a biologist at the Canadian Wildlife Service in Edmonton.
"It's the first time it's known to have happened in the wild."
Polar and grizzly bears have been bred together in zoos, but in the wild they rarely cross paths.
However, some grizzly bears have been seen venturing across the ice towards polar bear territory to search for food after emerging from hibernation. This might explain how the rare union occurred.
"In the limited area where the two species' ranges overlap, it is not entirely surprising that we might find a polar-grizzly hybrid," said David Field, Zoological Director of the Zoological Society of London.
"However, there are behavioural differences between the species, including timing of mating seasons, that make such hybrids highly unusual and it is unlikely that any resultant offspring would be viable."
Canadian wildlife officials are now thinking up a name for the creature. Some of the suggestions they have come up with so far are "pizzly", "grolar bear" or "nanulak", after the Inuit names for polar bear (nanuk) and grizzly bear (aklak).