Category Archives: Hybridization

BREAKING: DNA results prove so-called polar bear hybrid was a blonde grizzly

All the hubris last month about polar bear x grizzly hybrids, based on an unusual-looking bear killed near Arviat, has turned out to be wishful thinking by those who’d like to blame everything to do with polar bears on climate change. An awful lot of “experts” now have egg on their faces. That “hybrid” was just a blonde grizzly, as I warned it might.

grizzly-polar-bear-hybrid_Arviat 2016 Didji Ishalook

According to one report, Nunavut wildlife manager Mathieu Dumond said:

“Some otherwise pretty renown bear biologists jumped on the hybrid bear story without even knowing what they were talking about,” Dumond said.

“I think it was something blown out of proportion, with the wrong information to start.”

Gee, ya think? CBC ran a story too. But the CBC don’t really admit (see below) that they were the first out of the gate on this story and started the media madness. It was the CBC that relied on the opinion of a black bear expert from Minnesota (who likely only saw a picture) – but since he was willing to say it was a hybrid and that its presence was a sign of climate change, they went with it.  See “Grolar or pizzly? Experts say rare grizzly-polar bear hybrid shot in Nunavut: Expert says interbreeding may be happening more frequently due to climate change” (CBC 18 May 2016).

For background, see these recent posts on this putative hybrid and the issues on hybridization it spawned:
Another alleged grizzly-polar bear hybrid shot but it’s not a sign of climate change

Polar bear hybrid update: samples sent for DNA testing to rule out blonde grizzly

Five facts that challenge polar bear hybridization nonsense

Most polar bear hybrids said to exist have not been confirmed by DNA testing

Blonde grizzlies, like the one pictured below (which I posted the day the story broke), are actually a proven sign of natural variation within species – a critical lesson in biology that should be the take-home message here. [ADDED: 2007 Alaska Fish & Wildlife Service Newsletter article on colour variation in black and brown/grizzly bears. h/t Wayne D]

“Paging Professor Derocher”: PBSG biologist and University of Alberta professor Andrew Derocher gave so many interviews to the media on this issue I lost count – he fed the media frenzy almost single-handedly. Well, except for granddaddy of polar bear experts Ian Stirling, who said (via the Toronto Star)[update: Toronto Star published correction]:

“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.”

 

Grizzly light_NPS photo

Quotes from today’s story below.
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Most polar bear hybrids said to exist have not been confirmed by DNA testing

Although there are only two confirmed polar bear X grizzly hybrids (see recent posts here and here) – one in 2006 and a 2nd generation back cross in 2010 – there have been a few other unconfirmed sightings and/or hunters reports in addition to the Arviat animal shot last week, but how many?

Hybrid sightings Victoria Island spring 2012 Jodie Pongracz_GNWT

In a CBC radio interview today (27 May 2016), polar bear biologist Andrew Derocher claimed there have now been 9 polar bear/grizzly hybrids reported in Canada (with the Arviat animal shot last week being the 9th).

I think I’ve tracked down the details on those six unconfirmed Canadian sightings, plus another from Alaska. But as you will see, some of the reports are so vague it’s hard to know whether these are the animals Derocher counts as hybrids or not.
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Polar bear hybrid update: samples sent for DNA testing to rule out blonde grizzly

That putative polar bear hybrid shot in Arviat last week has been sent for DNA testing.

hybrid-bear_didji-ishalook-15 May2016_facebook

Just out from NunatsiaqOnline (24 May 2016): Nunavut biologist sends possible “grolar” bear DNA for analysis: Unusual bear killed in Arviat could just be a blonde grizzly bear

Additional details confirm the animal shot was a female, which could account for the fact it was described as “small”. The Nunavut biologist who sent in the sample for testing warned it could also be a blonde grizzly, as I pointed out last week.

UPDATE 24 May 2016: Comments added below from a Toronto Star news report below on the hybrid identity of this animal.

UPDATE 28 May 2016: See this 27 May 2016 follow-up post (Most polar bear hybrids said to exist have not been confirmed by DNA testing) for details on unconfirmed sightings or reports of hybrids.
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Five facts that challenge polar bear hybridization nonsense

It was inevitable, I suppose, that the putative hybrid shot in Arviat, Nunavut last week (see my post here) would initiate the global warming blame game.

Hybrids again_Washington Post 23 May 2016_title screencap

Washington Post, 23 May 2016, Adam Popescu: “Love in the time of climate change: Grizzlies and polar bears are now mating

Here are the five points you need to know about polar bear hybridization, as there are several nonsense statements contained in this Washington Post article.

UPDATE 24 May 2016: References adding below regarding grizzly sightings south of Churchill on the west coast of Hudson Bay (H/T Doug Clark).

UPDATE 28 May 2016: See this 27 May 2016 follow-up post (Most polar bear hybrids said to exist have not been confirmed by DNA testing) for details on unconfirmed sightings or reports of hybrids.

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Another alleged grizzly-polar bear hybrid shot but it’s not a sign of climate change

CBC News this morning (“Grolar or pizzly? Experts say rare grizzly-polar bear hybrid shot in Nunavut: Expert says interbreeding may be happening more frequently due to climate change“) suggests that a putative grizzly x polar bear hybrid bear shot outside Arviat in Western Hudson Bay is a sign of climate change, based on an interview with a black bear expert from Minnesota.

Hybrid pb shot in Arviat_CBC 18 May 2016

This bogus claim has been busted so many times it’s a wonder it still arises – even polar bear specialist Ian Stirling has said flat out that such hybrids are not due to climate change. On top of that, some of the details regarding this putative hybrid make me want to wait for confirmation from DNA testing before adding it to the roster of known hybrids.
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Ancestor of the polar bear by any name: grizzly vs. brown bear monikers explained

Apparently, all media outlets (except Fox News) so confused the distinction between the two common names used for the ancestor of polar bears, Ursus arctos, that they got the point of a recent news story totally wrong. An Alaskan journalist explains.

Coastal brown bears from Admiralty Island, southeast Alaska. See previous post here.

Coastal brown bears from Admiralty Island, southeast Alaska (courtesy Jim Baichtal, US Forest Service, Alaska). See previous post here.

Tundra grizzly from the Yukon (courtesy Government of Yukon Territory). These bears also occur across the north slope of Alaska and are the bears that occasionally hybridize with polar bears, as explained here.

Tundra grizzly bear from the Yukon (courtesy Government of Yukon Territory). These bears also occur across the north slope of Alaska and are the bears that occasionally hybridize with polar bears this time of year, as explained here.

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New genetic study confirms polar bears survived several warm Interglacials

There is a new polar bear genetics paper out in the Journal of Heredity, by University of Alaska Fairbanks genetics professor Matt Cronin and colleagues. Matt Cronin, in case you didn’t know, was the first to pick up the close genetic relationship between polar bears and grizzlies, as a result of research he and colleagues did back in the early 1990s (Cronin et al. 1991).

Figure1 from Cronin et al. 2014 (in press) showing the locations of bear samples used in their genetic study. MT, Montana; AK, Alaska; Polar bear samples were from the Chukchi, Beaufort and Barents Sea populations.

Figure 1 from Cronin et al. 2014 (in press) showing the locations of bear samples used in their genetic study. MT, Montana; AK, Alaska; Polar bear samples were taken from the Chukchi, Beaufort and Barents Sea populations.

While no earth-shattering new information was revealed in this new study, reported over the weekend by the Alaska paper SitNews (March 15), it used a more detailed method to confirm the results of previous work – that polar bears have been around long enough to have survived several past Interglacial periods that were warmer than today (with less ice in the Arctic) and are genetically distinct from grizzlies.

A feature that really set this work apart was how it was promoted.
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