Tag Archives: estimates

Polar bear population numbers are for kids, says specialist Andrew Derocher

Polar bear specialists made global population numbers the focus of the world’s attention when they predicted a dramatic decline and possible extinction of the species. But now that the numbers have increased slightly rather than declined, the same scientists say global numbers are meaningless: the public should give those figures no credence and anyone who cites global population numbers should be mocked.

NBC 2015_3 there will soon be a big decline in polar bear numbers snap

See the screen shot from a 2015 NBC news video above and another from the science journal NATURE in 2008 below (Courtland 2008):

Courtland 2008 headline

Yet, below is a recent message from one of the world’s most vocal polar bear specialists, four years after a similar incident raised the public’s ire:

Derocher tweet 2018 Feb 28 quote

However, you can’t make a plausible prediction of future survival without an estimate of present population size: not even today’s worst journalists would buy it, nor should they.
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Polar bear numbers not declining despite media headlines suggesting otherwise

In scanning comments generated by the recent flurry of internet interest in polar bears and blogs I noticed that a good many people, fed alarming media stories, are still convinced that polar bear numbers are declining rapidly when nothing could be further from the truth.

Crockford 2017_Slide 12 screencap

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Franz Josef Land is a sea ice refugium for most pregnant Barents Sea polar bears

Consensus polar bear expert Andrew Derocher has been busy over the last few weeks, expounding a story of doom regarding Svalbard area polar bears (e.g. here and here), ridiculing the suggestion that Franz Josef Land is viable alternate habitat for Barents Sea bears, especially pregnant females looking for a place to den and give birth. But the facts say otherwise.

Svalbard polar bear_Aars August 2015-NP058930_press release

Below are the long answers, with references and ice maps, to the questions Derocher asked in his 21 December 2017 tweet (above), a refreshing change from the ‘take my word for it, I’m the official expert’ answer one gets from him, along with derogatory slurs directed at those who don’t share his pessimism.

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Scientists and media continue to spread misinformation about polar bears & walrus

“Lies” might be a better word to characterize the misinformation that scientists and the media have been busy spreading to the public over the last few weeks. The information is either known to be false (by scientists whose job it is to relay facts honestly) or is easily shown to be false (by journalists whose job it is to fact-check their stories).

Churchill polar bear and walrus 2017

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Polar bear counts for W Hudson Bay: ‘core’ area numbers are not comparable

Polar bear population estimates for Western Hudson Bay have recently become contentious because one specialist has been making statements that confuse the issue. As we all wait for the release of the report on the WHB aerial survey of 2016, it’s worth going over the recent history of these counts and what they have revealed.

Churchill_Polar_Bear_2004-11-15 Wikipedia

The official count for bears in WHB (used by the IUCN Polar Bear Specialist Group, the IUCN Red List, and Environment Canada) is 1030, based on an aerial survey of the entire region conducted in 2011 (Stapleton et al. 2014).

Since last year, Andrew Derocher (University of Alberta) has been telling any media pundit who will listen that WHB polar bears have declined from about 1200 bears in the 1980s to only 800 or so bears today (one example here) — a statement that is clearly not true.  In recent months, however, whether due to complaints from the public or from his colleagues, he’s qualified that statement by saying it’s the number of bears in the “core” area of WHB that has declined.

But is Derocher’s revised statement a clear scientific interpretation of the facts? Have a look at the details below and see if you come to the same decision I have: that it’s not possible to compare WHB ‘core’ area polar bear population estimates over time.

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