Category Archives: Population

Polar bear researchers knew S Beaufort population continued to increase up to 2012

Why did the Southern Beaufort polar bear population survey stop in 2010? It’s clear that the recently-published and widely-hyped new study stopped before the population rebound from a known decline was complete.

USFWS 2013-2014 PB News_cover_PolarBearScience

The researchers of the recently-published paper knew before starting their mark-recapture study in 2007 that the population decline had taken place. They also knew why the numbers dropped and that previous declines, caused by similar conditions, had been followed by a full recovery.

Did they really think a full recovery in population numbers was possible in only three four years, when cubs born in 2007 would not yet have been old enough to reproduce?

In fact, a US Fish and Wildlife Service (USFWS) fall survey of Southern Beaufort polar bears in 2012 found numbers were higher than they had been in a decade.
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S Beaufort polar bears largely recovered from known 2004-2006 decline, says new study

A bit more good news about polar bear populations, this time from an abundance study in the Southern Beaufort Sea. A paper released yesterday showed a 25-50% decline in population size took place between 2004 and 2006 (larger than previously calculated). However, by 2010 the population had rebounded substantially (although not to previous levels).

All the media headlines (e.g. The Guardian) have followed the press release lead and focused on the extent of the decline. However, it’s the recovery portion of the study that’s the real news, as it’s based on new data. Such a recovery is similar to one documented in the late 1970s after a significant decline occurred in 1974-1976 that was caused by thick spring ice conditions.

Polar bear with collar and tag_USGS_labeled

The title of the new paper by Jeffery Bromaghin and a string of polar bear biologists and modeling specialists (including all the big guns: Stirling, Derocher, Regehr, and Amstrup) is “Polar bear population dynamics in the southern Beaufort Sea during a period of sea ice decline.” However, the study did not find any correlation of population decline with ice conditions. They did not find any correlation with ice conditions because they did not include spring ice thickness in their models – they only considered summer ice conditions.

I find this very odd, since previous instances of this phenomenon, which have occurred every 10 years or so since the 1960s, have all been associated with thick spring ice conditions (the 1974-76 and 2004-2006 events were the worst). [Another incident may have occurred this spring (April 2014) but has not been confirmed].

Whoever wrote the press release for this paper tried hard to suggest the cause of the 2004-2006 event might have been “thin” winter ice caused by global warming that was later deformed into thick spring ice, an absurd excuse that has been tried before (discussed here). If so, what caused the 1974-1976 event?

It seems rather unscientific as well as implausible to even try to blame this recent phenomenon on global warming. However, neither the authors of the paper or the press release writers seemed to want to admit that 2-3 years of thick ice development in the Southern Beaufort could have been the cause of the population decline in 2004 (as for all of the previous events). No, that wouldn’t do, not in the age of global warming.

So, we are left with this equally absurd conclusion from the author:

The low survival may have been caused by a combination of factors that could be difficult to unravel,” said Bromaghin, “and why survival improved at the end of the study is unknown.

I’ve summarized the paper to the best of my understanding (there was a lot of model-speak to wade through), leaving out the prophesies of extinction, which in my opinion don’t add anything.

UPDATE November 19, 2014: Don’t miss my follow-up post, with some startling new information, Polar bear researchers knew S. Beaufort population continued to increase up to 2012
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BBC provides a forum for desperate biologists: “Will polar bears become extinct?”

Yesterday, the BBC published a story that gave the two most alarmist polar bear researchers on the planet a forum to market their ‘polar bears are doomed’ message. This time the desperation shows: watch how these biologists move the goal-posts, make claims so misleading they border on lies, and pretend they don’t have big, big trouble with their predictive models.

Amstrup_only solution_with 2 cubs_Oct 8 2014

Amstrup photo that accompanied an interview last month.

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Polar bear specialist says there are 800 polar bears in W Hudson Bay, gov’t says ~1,000-1,500

Activist polar bear biologist Andrew Derocher (University of Alberta) may have gone too far this time. In an interview with Yahoo News, Derocher is quoted as saying:

“When I first started here about 30 years ago the population was about 1,200 bears and now we’re down to about 800,” team member Andrew Derocher, a biology professor at the University of Alberta, said in a phone interview from the tundra outside Churchill.”  [my bold]

Figure 4. Environment Canada's "Map 3: 2014 Canadian Polar Bear Subpopulation and Status Map," original here.

Environment Canada’s “Map 3: 2014 Canadian Polar Bear Subpopulation and Status Map,” original here. Click to enlarge.

However, the Polar Bear Technical Committee of Environment Canada says differently: it estimates there are ~1000-1,500 bears in Western Hudson Bay (WH) and that the population is probably stable, as their new status map (dated June 2014, copied above) shows. A recent (2014) peer-reviewed paper by Stapleton and colleagues (discussed here) provides the data for that estimate.
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Polar bear biologists doing mark-recapture work in Hudson Bay may have misled the world

What exactly are Western Hudson Bay (WHB) polar bear researchers hiding? Since 2004, research on the body condition and cub production of Western Hudson Bay (WHB) polar bears has been carried out but none of the results of these mark-recapture studies have been made public.

U Alberta student Mislan bio photos_PolarBearScience

The researchers all claim that WHB polar bears are struggling to survive because of recent sea ice changes but won’t release the 10 years worth of updated information they possess on the bears or the sea ice.

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Status of Canadian polar bear populations has been changed – more good news

According to maps dated June 2014, Environment Canada (EC) has changed the trend status of several Canadian subpopulations — without any announcement or publicly-available documents explaining the basis of the changes.

Figure 3. "Series of Circumpolar Polar Bear Subpopulation and Status Trend Maps 2010, 2013 & 2014" Note the asterisk below the 2014 map, which is dated "June 2014" and is different in its status assessment from the one released in February 2013 by the PBSG. Original here.

Figure 1. Environment Canada’s “Map 4: Series of Circumpolar Polar Bear Subpopulation and Status Trend Maps 2010, 2013 & 2014.” Original here.

And would it surprise you to learn that virtually all of these status changes reveal more good news about polar bears?
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Beaufort Sea polar bear subpopulation boundary has been changed

Environment Canada recently posted a set of maps on its website that show it has moved the boundary between the polar bear subpopulation it shares with the USA — without a word to the media or a note anywhere.

EC S_N Beaufort boundary change Sept 8 2014_cropped PolarBearScience

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