Even though it is well known that subadult male polar bears (≤ 4 years old) continue to grow in mass and bulk as they mature – so that their thick necks get even larger – in recent years Andrew Derocher and his students at the University of Alberta potentially endangered the lives of many subadult males in the Southern Beaufort in the process of learning relatively little they didn’t already know.
Money quote from a just-accepted paper by Master’s student Jody Pongracz and supervisor Derocher (“Summer refugia of polar bears (Ursus maritimus) in the southern Beaufort Sea” Polar Biology, in press 2016):
“The number of bears tracked varied over time due to collar design, deployment, and both planned and unplanned collar retention.”
So, how much “unplanned collar retention” issues [collars that did not fall off as expected] went on during this 2007-2010 study? They don’t say.
Is this paper saying U of A researchers knew they had ‘collar retention’ issues as far back as 2010 but continued to deploy them on subadult males after that study was over? It seems so, because they had an issue with just such a bear last year.
The bear with an apparently tight collar that was photographed last fall (see photo above) went out onto the ice and no one knows what happened – there has been no more information on him since, although researchers have apparently been watching for him, updated just yesterday). The University of Alberta statement says (under the June 2 update):
“Ongoing research at the University of Alberta is shifting to ear tag radios as required”
So now they realize that putting collars on subadult males is not such a good idea. Brilliant!
CBC News (28 October 2015): “Photo shows polar bear injured by tight radio collar“. See previous posts here and here. In a Global News interview (23 November 2015), Derocher admitted his team had “likely” put the collar on that bear, prompting the University of Alberta to issue a “Q & A” statement on the incident – which continues to insist that failure of collars to release is “rarely seen.”
Posted in Life History, Sea ice habitat, Uncategorized
Tagged Andy, Derocher, failures, problems with collars, satellite collars, sea ice, Southern Beaufort, subadult males, thick spring ice, tight collar, University of Alberta
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?
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.
Posted in Conservation Status, Hybridization, Sea ice habitat
Tagged Alaska, Canada, Derocher, grizzly, grolar, hybrid, pizzly, polar bear, sightings
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.
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.
Posted in Conservation Status, Hybridization, Sea ice habitat
Tagged Amstrup, Arviat, climate change, Derocher, global warming, grizzly, grolar bear, hybrid, northward expansion, Nunavut, pizzly, polar bear, range contraction
[Reposted today from earlier this year in support of the 2 May release of the intentionally funny documentary, Climate Hustle (across the US and a few Canadian locations) because host Marc Morano knows that polar bear numbers have not declined as people have been led to believe, see the trailer below]
Grim predictions of the imminent demise of polar bears – their “harsh prophetic reality” as it’s been called – have been touted since at least 2001. But such depressing prophesies have so widely missed the mark they can now be said to have failed.
While polar bears may be negatively affected by declines in sea ice sometime in the future, so far there is no convincing evidence that any unnatural harm has come to them. Indeed, global population size (described by officials as a “tentative guess“) appears to have grown slightly over this time, as the maximum estimated number was 28,370 in 1993 (Wiig and colleagues 1995; range 21,470-28,370) but rose to 31,000 in 2015 (Wiig and colleagues 2015, pdf here of 2015 IUCN Red List assessment; range 22,000-31,000).
Here are the failed predictions (in no particular order, references at the end):
Posted in Advocacy, Conservation Status, Population
Tagged Amstrup, Climate Hustle, declining population, Derocher, facts, failed prophesies, polar bear, population size, predictions, Red list, sea ice, Stirling
The air is thick with desperation on the polar bear front:
“[Andrew] Derocher said the polar bear population in the Beaufort Sea has fallen more than 50 per cent in the past 10 years.
“So it is a concern that this is probably one of the factors associated with the population decline,” he said.
As the CBC report in which this quote appears states immediately afterwards, there is no evidence for such a thing in the paper under discussion:
“The study found no direct evidence of that – all polar bears appeared to survive the swims recorded in the study.”
There is no truth to Derocher’s first statement either. Desperation – you don’t have to be a scientist to sense it. And the media wonder why people don’t trust them…
Posted in Uncategorized
Tagged Beaufort Sea, Derocher, desperation, Earth Day, facts, hype, Michaels, polar bear, population crash, sea ice, swimming
You may have seen the headlines in Canadian news outlets over the last 2 days.
“Polar bears swimming farther as sea ice recedes, study shows”
“Melting sea ice forces polar bears to swim longer, farther: study” [“Bear biologist Andrew Derocher says the forced swims are particularly hard on mothers with young cubs”]
“Polar bears swimming longer, farther because of melting sea ice, study finds”
Oddly, none of the above news reports said where the paper was published or mentioned the name of the lead author – only University of Alberta co-author Andrew Derocher was interviewed (see the only press release I could find here, issued by the San Diego Zoo where the lead author is now employed).[update: CBC ran another story a day later that corrected these omissions]
But what did the study actually say?
Significantly, no bears died while swimming during the two lowest sea ice extent summers since 1979 and no evidence was presented that swims were “particularly hard on mothers with young cubs.” The quotes from the paper below sum it up for Beaufort Sea (BS) bears (the inclusion of Hudson Bay (HB) bears in this study seems gratuitous and potentially misleading, since only a few swam anyway – only 15 out of 59):
“….91% (91/100) of the swims in the BS occurred before the annual September minimum sea ice extent had been reached. …In the BS, 81% (29/36) of swims started and ended in pack ice…”
So, despite what may be implied during media moments, Beaufort Sea polar bears were not frantically trying to reach the sea ice from land so that they could attempt to keep feeding over the summer – most of their swimming was done during breakup in July and August from one bit of pack ice to another and they showed no evidence of harm from doing so. Map from the study and more quotes below.
Posted in Life History, Sea ice habitat
Tagged Beaufort, Derocher, forced swims, Hudson Bay, mothers with young cubs, Pilfold, polar bear, receding sea ice, sea ice, summer, swim longer, swimming, swimming further
According to sea ice experts, winter sea ice habitat for polar bears is not expected to decline at all by 2050 and the critical spring sea ice that polar bears need for gorging on young seals and for mating is not predicted to change much (Durner et al. 2007, 2009), which is why computer modelled predictions about the dire future for polar bears only assessed the potential future effects of declining summer sea ice (e.g. Amstrup et al. 2007; Stirling and Derocher 2012). Note spring is April-June.
See if that fact is clear in the interview responses by out-spoken polar bear biologists that has just been published in the polar bear portion (“Beyond the polar bear”) of this year’s University of Alberta magazine spring climate change feature. If you can get past the “canaries in the coal mine” opener…
Posted in Advocacy, Sea ice habitat
Tagged advocacy, Derocher, facts, interview, polar bear, predictions, sea ice, spring sea ice, starving polar bears, Stirling, summer sea ice