RANKIN INLET - It's come to be known as a grolar bear - the offspring of mating between a polar bear and a grizzly bear.

And during the past few months, stories of grolars running around the Kivalliq have grown in popularity.

Hunters and observers gather around a grizzly bear shot near Rankin Inlet in late April or early May 2009. -

However, there has been only one confirmed case of a grolar bear in the wild, and that was from Banks Island near Sachs Harbour in the NWT back in April of 2006.

Dr. David Paetkau is the president of Wildlife Genetics International, the Nelson, B.C., company that did genetic testing on the NWT bear.

Paetkau said if regional hunters are shooting bears thinking they're grolars, it's almost inevitable they're shooting grizzlies needlessly.

He said a grizzly breeding with a polar bear is very, very rare, if, indeed, there has been more than one.

"The Nunavut government, the NWT and the Alaskans have been out on the ice for years and years, and have caught thousands of bears," said Paetkau.

"We have genotypes on file for more than 2,000 polar bears and genetic data confirms they are strictly polar bears, not hybrids.

"So when you have sample sizes like that and none of them are hybrids, it says that it's a very rare event."

Paetkau said with a sample size of one confirmed grolar bear, you can explain the occurrence any way you want.

He said there's no way of knowing the biological meaning of the event.

"It could be something that's just happened from time to time throughout history because they don't have much reproductive success.

"Or, it could be something that does relate to more temporary circumstances (climate change).

"We just can't say with a sample size of one."

Polar bears and grizzlies are closely-related species.

They produce viable and fertile offspring in zoos, indicating no barriers exist from a physiological or genetic perspective.

However, behaviour comes into play in the wild and the chances are quite high the hybrids would not have the mating success necessary to perpetuate the breed.

Paetkau said his company's work on the grolar bear was not something it normally works on, and it's been as interesting to staff members as anyone else to see how it captured the public's imagination.

He said the response was far greater than he would have anticipated.

"I would caution people this is far too rare of an event to think you're going to be able to go out and find one deliberately, which is really a wrong-handed idea.

"The events will prove themselves too rare to do studies in any practical way, so we really wouldn't learn too much by pursuing the issue aggressively.

"Of more interest are the Northern occurrences of grizzly bears and the documenting of them, at seemingly higher frequencies, north of the mainland than has historically been the case.

"That's interesting in the context of quite a few species seeming to be rolling northward."