https://www.thestar.com/news/c...lar-bear-hybrid.html



Did Nunavut hunter shoot grizzly-polar bear hybrid?

Many grizzly bears with polar bear ancestry in their genes survive, researcher says. But the opposite is almost never true, perhaps because polar bears must be all-white to hunt and survive.



By ALLAN WOODSQuebec Bureau
Mon., May 23, 2016


When Didji Ishalook spotted the animal on the crest of a hill during a recent hunt in Nunavut he thought he had either an Arctic fox or a polar bear in his sight.

Only when the 25-year-old approached his kill did he realize he might have something even rarer.

“They’re saying it’s a grizzly-polar bear hybrid,” he said in an interview from his home in Arviat, 250 kilometres north of Churchill, Manitoba.

Known either as a grolar or a prizzly depending on whether the father is a grizzly or polar bear, the find — which can only be confirmed through genetic testing—is so rare that only a half-dozen or so kills have been confirmed in the last decade.

“I think it’s 99 per cent sure that it’s going to turn out to be a hybrid,” said Ian Stirling, an emeritus research scientist with Environment Canada and adjunct professor at the University of Alberta.

Ishalook’s bear, which was caught in accordance with laws that allow Inuit to practice subsistence hunting, has now been skinned and the fur is sitting in his freezer, though he plans to send it to a taxidermist. Photos of the freshly killed animal were posted to Facebook earlier this month, picked up by the CBC and are now buzzing through international scientific circles.

They are attracting attention not only for the rarity of the potential find — the first confirmed polar-grizzly hybrid in recent memory was trapped in 2006 — but for what it might tell us about bear evolution and adaptation in the face of climate change.

“The unusual thing here is how did a male grizzly bear bump into a female polar bear,” said Andrew Derocher, a biology professor at the University of Alberta who studies the effects of climate change on polar bears.



“Most of the mating activity of polar bears is occurring out on the sea ice, so there’s a spacial discontinuity between where a grizzly bear would be in the spring and where a polar bear would be in the spring.”

He said that Ishalook’s bear does not appear to be an albino grizzly. If it is just a very blonde grizzly it would be the palest he has ever seen. But its claws appear to be longer and more “grizzly-like” than other hybrids that have been caught and examined.

“We haven’t done the genetics on this and, until we do, we won’t really be able to say anything conclusively,” Derocher said.

In most cases, hybrids are the result of male grizzly bears travelling and mating with female polar bears. This occurs because male grizzlies emerge earlier from winter hibernation and head out in search of food while female grizzlies tend to stay close to home.

Warmer temperatures in the Arctic may be one reason that grizzly bears are wandering north, bit it’s not the only one. Improved population-management techniques and strict hunting quotas have also allowed the grizzly populations to grow and forced them to seek out new territory.

David Garshelis, a bear specialist and adjunct professor at the University of Minnesota, said there have been documented cases of grizzlies and polar bears feasting together on a whale carcass in the area of Hudson Bay.

This sort of intermingling is necessary because it takes several days of contact to induce ovulation in female polar bears.

“The fact that a grizzly and polar bear are mating tells you that they’re hanging out,” said Stirling, a specialist in polar bear behaviour. “This isn’t just a casual one-night stand kind of thing.”

It also points to the historical and genetic links between the species, as does the fact that the cubs can themselves go on to reproduce.

The offspring of these unions can vary quite a bit. Derocher said that one set of sibling grolars found several years ago with their polar bear mother looked nothing alike: one resembled a polar bear while the other was more like a grizzly.

But the survival of hybrid cubs depends greatly on what species they act like, said Beth Shapiro, an associate professor at the University of California Santa Cruz specializing in genome evolution and ancient DNA.

In her studies of bear hybrids, Shapiro has discovered many grizzly bears with polar bear ancestry in their genes. But the opposite is almost never true. This suggests that such offspring just don’t survive as polar bears in the Arctic, Shapiro said.

“Being white is obviously absolutely critical to both hiding and hunting (in the Arctic),” explained Stirling, who has worked with Shapiro. “For a grizzly bear that’s feeding on vegetation or in the salmon stream, it really doesn’t matter what colour it is. There’s no disadvantage to being black or white or whatever.”

Finding the genetic material of polar bear in grizzly bears has all sorts of possible implications in the face of a changing climate and warming Arctic, which is causing sea ice to melt and could put the polar bear populations at risk.

“There have been warm spells in the Arctic before — warmer than it is right now — and there wasn’t a lot of ice around. One of the questions has always been how these bears survived” said Stirling. “It seems like to some degree hybridization may have been part of the process that was involved in maintaining the polar bear gene through warmer periods.”

Both Stirling and Shapiro said governments should consider protecting the rare hybrid bears because of the clues they may yield about polar bear evolution and how the species is affected by and responds to climate change.

“The more we learn about evolution and DNA, we learn that (hybrids) aren’t at all unnatural,” Shapiro said.

“This is maybe an evolutionary mechanism for polar bear DNA to stick around even if polar bears can’t because of climate change.”

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Very interesting stuff. Thanks for posting. Brian

"Thought he had an Artic Fox,or a Polar Bear in his sight"............What did he do shoot a Cub ?

In 2011, we hunted caribou in norther Manitoba very close to the border with Nunavut. Even though we were over 100 miles away from the ocean, we were warned to watch out for polar bears. They had been spotted in the area and had taken downed caribou from hunters. I do not at all doubt there are some mixes.

There was a hunter a few years ago who shot a polar grizzly cross near TUK that the game dept DNA tested and found to be a half and half. Hunter was allowed to keep it.
2010 polar grizzly hybrid

This is nothing new. There have been several instances of hunters killing the polar/grizzly crosses. Last time I hunted in the Arctic there was a life size mount of one of these bears in the remote airport servicing the community.

The barren ground grizzlies are expanding their range. They have been seen a long ways north in the Arctic islands and down into Manitoba as far south as York Factory.

Polar bears do range quite far inland from Hudson's Bay. From the northern Arctic coast line on the mainland of Canada there have been polar bears that wandered a long ways from the coast.

Anyways, cross breeds in the area of Arviat is just not much of a surprise really, as it is prime habitat for polar bears and barren ground grizzlies.

Nope just a Blonde Grizzly

It turns out an odd-looking bear shot and killed by a hunter in Arviat, Nunavut, last month wasn't a hybrid of a polar bear and a grizzly bear — it was a blond grizzly.

Experts say rare grizzly-polar bear hybrid shot in Nunavut

The hunter, Didji Ishalook, described the animal as being shaped like a grizzly, but with the colouring of a polar bear. "It turned out to be a grizzly half-breed," he said at the time.

But Nunavut's Department of Environment (DOE) has confirmed that the "unusual" bear is not a hybrid.

"DOE submitted a tissue sample to a genetics lab for DNA analysis in order to verify the ancestry of the harvested bear," Carrie Harbidge, an environmental education specialist, told CBC News.

"The DNA lab concludes that the animal was a blond grizzly bear, and it does not have a polar bear parent. Therefore, the harvested bear was not a hybrid."

People got 'carried away'

"From people on the ground, in the field, it was somewhat obvious that the results would come [out] that way," says Mathieu Dumond, a wildlife manager for Nunavut's environment department. "I think the excitement of a few hybrids found in the western part of Nunavut and in N.W.T ... got people carried away a little bit."

Ishalook had consulted with elders in Arviat before concluding the bear he'd shot was a mix. At the time, CBC News also spoke with a Minnesota-based leading bear expert, who concurred.

Grizzly-Polar Bear Hybrid
Nunavut's environment department says this 'unusual' looking bear is a blond grizzly bear and not a grizzly-polar bear mix, as some first believed. (Submitted by Didji Ishalook)

Dumond says that's why it was important to verify the assessment with genetic testing, especially since there have been two or three confirmed cases of grizzly-polar bear mixes.

"It's so rare that unfortunately I think nobody has a lot of experience in identifying a hybrid from the first sight."

Blond grizzlies are far less rare, he adds: "While it's not maybe the most common colour for the fur ... it's not something extraordinary. Every year we see some that are blond."

Unless you have spent a massive amount of time spent looking at both types, grizzly and polar, I don't think the average once or twice in a lifetime could tell the difference between a white grid and a plan bear bear and the hunter shouldn't be crucified for shooting. I'm hunting in a snow/ice covered world and a white colored bear walks by,who wouldn't have fired the shot...by the looks of the photo I'd pushed the safety off !

One genetically verified hybrid has been harvested. It was in a post here a couple years ago.

Saw a documentary on TV about it...just goes to show ya everything's possible !