Monthly Archives: June 2016

USGS polar bear researchers publish their rebuttal to 2015 IUCN Red List assessment

Surprise! US Geological Survey polar bear specialists have just published another opinion-based model that concludes – yet again – that there is no hope for polar bears of the future unless the world drastically reduces fossil fuel use. This appears to be the Amstrup-led rebuttal to the hated 2015 IUCN Red List polar bear assessment I have been expecting, written in tandem with the Red List document by two of the same co-authors (Steve Amstrup and Todd Atwood).

Kaktovik female w cub_21 September 2015 USDA_med

Really, no surprises here – just more of the same overwrought fear-mongering about polar bears that we’ve been hearing from USGS since 2007. I saw Atwood and Amstrup last week in a British-made TV film that expressed the same sentiments (The Great Polar Bear Feast – it oddly featured dozens of fat/very fat Kaktovik polar bears while mostly USGS ‘experts’ talked about impending starvation). On camera, Atwood and Amstrup were almost indistinguishable in their statements of doom, and even though the film aired 6 months ago in the UK, it has so far not garnered the angst it seems to have intended.

Some folks may be even more convinced than ever by this new PR strategy [TV movie plus a published paper] that the polar bears are all going to die unless we (not they) change our wicked ways and stop using fossil fuels, but chances are that many more will detect the desperation in their escalated pitch and continue to refuse to buy what they are so frantically trying to sell.

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Polar bears and W. Hudson Bay sea ice breakup 2016

Breakup for Western Hudson Bay (WHB) is looking to be later than usual this year, given that the average breakup date since 1991 has been July 1 (using a 30% threshold) – only a few days from now – and the ice in WHB is nowhere near 50% coverage, let alone 30%.

Churchill_Polar_Bear_2004-11-15 Wikipedia

Note that few WHB bears come off the ice around Churchill – most come ashore along the southwest coast of Hudson Bay (almost into SHB) and make their way north over the course of the summer to meet the ice as it reforms in the fall north around Churchill – that’s why it’s called a “migration.”


There’s still a lot of ice left in Hudson Bay, as the Canadian Ice Service map for 29 June 2016 (below) shows: Sea ice extent Canada 2016 June 29 CIS

It seems to me that breakup for WHB this year is looking rather like 2014, which was something like a week later than the average since 1991, but time will tell. See below for comparison to 2009 (a late breakup year), 2015, and 2013 (lots of variability!), as well as a discussion of when bears come ashore in relation to this sea ice breakup benchmark.

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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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Five years of polar bear habitat at June 20 around the Arctic

Five years worth of sea ice maps for the same date is hard to come by in this country, since the Canadian Ice Service does not archive their daily sea ice maps. However, due to some forethought, I have at hand ice maps going back to 2012 for the longest day of the year for Canada and archives for other regions provide similar perspective at the solstice.

Polar_Bear_male on sea ice_Regehr photo_March 21 2010_lg

Few photos of polar bears in June likely exist – too early for most bears to come ashore and the ice too unstable for humans to be offshore [photo above is dated March].

Compare the five maps for Canada and eastern Alaska below. Notice the differences for Hudson Bay: it may seem ironic, but 2012 (which had the lowest September minimum since 1979 due to an August storm) had the most typical Hudson Bay breakup/melt pattern compared to previous years. [Keep in mind this recent post about how much ice can remain even when almost none is visible on the ice maps]

In many regions, polar bear hunting efforts are seldom successful after early June because young-of-the-year seal pups have taken to the water to feed, which means the only prey still on the ice are predator-savvy adults and subadults that have an easy time escaping in the rapidly breaking up ice fields. Bears that come ashore in June likely are not missing much – a little less ice than usual at this time of year is not going to make much difference.

Overall, despite doom and gloom predictions we heard in March 2016 (“wintertime extent hits another record low”), sea ice extent (courtesy NSIDC) at 20 June 2016 was the same at this date as it was in 2010 and 2012 at this time of year – which essentially marks the end of the primary feeding period for polar bears (except for those that live in the Canadian Arctic Archipelago, where seals give birth a bit later in the spring).

Sea ice at 20 June_2016 vs 2012 and 2010_NSIDC interactive

And did polar bears die in droves due to conditions in 2010 or 2012, in any subpopulation around the Arctic affected by low sea ice levels? No, they did not. In fact, the subpopulation that had the most recent survey done (Svalbard portion of the Barents Sea – 2015) was not only found to be thriving but numbers had increased markedly (42%) over 2004 levels. Now that’s resilience!

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Terrestrial food fight amongst polar bear researchers reflects political differences

With a few big guns on one side and some fringe folk on the other, a dichotomy of opinion has developed amongst polar bear researchers regarding whether or not consumption of land-based foods is making a difference to polar bear survival (or is likely to in the future).

Polar bears eating terrest foods WHB_Rockwell press release

It’s been going on for a while now. Last year, two US Geological Survey members of the IUCN Polar Bear Specialist Group (PBSG) apparently got fed up with the scatter-shot of papers promoting terrestrial foods as a possible salvation for polar bears (e.g. Iles et al. 2013;  Iverson et al. 2014; Rockwell and Gormezano 2013a, 2013b). In April, they published a canon volley of a paper meant to blow all that ‘polar-bears-might-survive’ talk out of the water once and for all (Rode et al. 2015).

Note that although the PBSG didn’t bother to update their website with the IUCN Red List assessment when it came out last November, they had a link up to the USGS terrestrial feeding paper within 16 days (with an editorial summary in the “NEWS” section as well as a listing of the paper in the “RECOMMENDED READING” section). As I suggest below, this difference in treatment may not be a coincidence.

However, another group of non-PBSG researchers  haven’t given up just yet, as shown by the title chosen for the most recent news report (Alaska Dispatch News, 16 June 2016) on the just-finished International Bear Conference:

Want to know how a changing climate is affecting polar bears? Look at what they’re eating.

Apparently, Jeff Welker, a University of Alaska Anchorage researcher who is co-author on two recent papers on the subject of polar bear consumption of terrestrial foods (Tartu et al. 2016 and Rogers et al. 2015), gave a presentation at the conference that raised this topic yet again. His talk came on the heels of an earlier presentation by Todd Atwood, who suggested Southern Beaufort polar bears might benefit from staying onshore to eat left-over whale scraps instead of staying on the sea ice during the summer (even though he had no data to support that opinion – as I discussed in this post).

Here’s the question: is this dispute really about what polar bears eat or don’t eat when they’re on land – or is it symptomatic of the underlying politics of polar bears? [CBC documentary video by that name here]
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PBSG failure to acknowledge 2015 IUCN polar bear update drives the public here

It is now past the 15 June 2016 mark and the IUCN Polar Bear Specialist Group (PBSG) has still not acknowledged the 2015 IUCN Red List update on the status of polar bears. See the screencap below, taken this morning.

PBSG at 16 June 2016

This notice has been up since 14 January 2016 and no reference or link to the November 2015 IUCN Red List update has been posted, even though PBSG members authored the report (pdf here)!

What they may not realize is that their silence just drives people who search the internet looking for up-to-date population and conservation status info on polar bears to this site. My posts on population size and conservation status have been the most popular posts since November.

It’s that kind of attention that has made this site so popular: PolarBearScience will reach 750,000 views within the next couple of weeks (see “Blog Stats” lower right) – that’s right, 3/4 million views in less than four years. More than 400,000 readers have come here since the end of July 2012 to find out what’s really going on in the world of polar bears. Continue reading

Polar bears are not bloodthirsty killers, says biologist [just don’t forget your gun]

According to records compiled by James Wilder, a US Forest Service biologist, there were only 20 fatal polar bear attacks (out of 73 total attacks) between 1870 and 2014.

That’s what the 14 June 2016 account in the Anchorage Daily News says (“Sea ice has been keeping polar bears and humans apart — until now”). But I think it’s kind of delusional to suggest that a list of recorded attacks, spanning 145 years throughout the Arctic (including Russia), have captured more than a fraction of all actual polar bear attacks – given that many Arctic communities didn’t have reliable communications in the 1970s (let alone the 1870s). How about all the Inuit and Siberian hunters over the years who failed to return home because they were killed and eaten by a polar bear – unbeknownst to anyone?

Alaska PB USGS_marked

Wilder presents these numbers as a basis for saying how concerned he is that a longer open-water season in the Arctic could increase the number of attacks by polar bears – and he’s right, that’s a valid concern now that the global population of bears is so high. Many polar bears plus people in a confined area is never a comfortable situation, as the people of Churchill, Manitoba have learned.

But declining sea ice is not the only scenario that could lead to an onslaught of hungry bears and a slew of fatal attacks, as my new science-based novel EATEN highlights. The truth is that if polar bears don’t get enough food in the spring – for any reason – the ice off the beaches of Arctic communities gives polar bears easy access to human prey. If that happens, people had better be prepared – because doors and windows won’t necessarily stop a determined polar bear.

EATEN ebook sale 2016 susancrockford_dot_com

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