Tag Archives: survey

Breaking: 2016 W. Hudson Bay polar bear survey shows the population is still stable

A just-released report on the most recent (2016) survey shows Western Hudson Bay polar bear numbers were still stable despite predictions that this subpopulation would be wiped out completely (reduced to zero) due to low Arctic sea ice.

Churchill_Polar_Bear_2004-11-15 Wikipedia

The authors of the report on the August 2016 aerial survey of the Western Hudson Bay polar bear subpopulation (Dyck et al. 2017) state clearly that the only trends they could find were that the number of adult males increased somewhat over 2011 estimates and the number of females either declined or remained stable. The overall population estimate was a bit lower (11% less) compared to the 2011 survey but the difference is not statistically significant. Therefore, the population status must be stable.

2011 estimate: 949 bears (using comparable data, range 618-1280), litter size 1.43

2016 estimate: 842 bears (using comparable data, range 562-1121), litter size 1.63

[cf. Foxe Basin [stable], from 2009-2010 survey (Stapleton et al. 2016) litter size was 1.54]

An 11% decline in WH numbers since 2011 is most definitely NOT the decline to ZERO (extirpation) we were told to expect with Arctic sea ice as low as it has been since 2007 (Crockford 2017, see list of annual minimum extents 2007-2017 here).

Note: The percentage decline from 2011 to 2016 for Western Hudson Bay polar bears is 11%, NOT 18% as claimed recently by Andrew Derocher on twitter: it is not appropriate to compare the official 2011 estimate of 1030 (Stapleton 2014) to the 2016 estimate of 842 because the methods used to generate the estimates were different (Dyck et al. 2017). The authors of the report state that the estimate for 2011 that’s comparable to 2016 is 949.

An 11% decline from 1030 would be 917 bears, a statistically insignificant decline that is also biologically insignificant and therefore, so slight as to indicate a stable population.

Predicted sea ice at 2050 and 2080 shown below (see Crockford 2017 for details):

Crockford 2017 sea ice graphic

Quotes, map, and table from the Dyck et al. 2017 report (pdf here) are copied below.

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IUCN PBSG insists the 2015 Barents Sea polar bear count was not an increase

Similar to the spin on the 2013 Baffin Bay/Kane Basin polar bear population survey, the IUCN Polar Bear Specialist Group now insists the latest count of the Barents Sea subpopulation is not evidence of an increase in numbers since 2004, as the leader of the study announced in 2015.

Svalbard polar bear_Aars August 2015-NP058930_press release

This is Part 2 of the big surprises in the latest version of the polar bear status table published by the IUCN Polar Bear Specialist Group (PBSG) on 30 March 2017. See last post here regarding the PBSG population size estimates that no longer concur with the 2015 Red List assessment, including the global total — even though PBSG members wrote the report (Wiig et al. 2015, and its Supplement).

Here I want to focus on the results of subpopulation surveys that were made public after the 2015 Red List assessment was published, particularly the Barents Sea estimate.

While the 2013 Baffin Bay and Kane Basin estimates (SWG 2016) have been added to the new PBSG table, any suggestion that these might indicate population increases are strong discounted. Similarly, contrary to initial reports by the principal investigators of the survey, the PBSG insist that the Barents Sea population has not actually increased since 2004, which you may or many not find convincing.

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W. Hudson Bay had 1030 polar bears at last count and that is the official number

The IUCN Polar Bear Specialist Group, the IUCN Red List, and Environment Canada (see below) agree that the population size of Western Hudson Bay subpopulation is 1030 or about 1000 bears, based on surveys conducted in 2011.

western-hudson-bay-surveys-2011-compared_polarbearscience-16-dec-2016

For the last few months (most recently, here and here), Andrew Derocher has been telling anyone who will listen that that the number is 800. And no one challenges him – not a single reporter asks where the number comes from, not a single research colleague who knows the truth has publicly stated that Derocher is spreading misinformation.

UPDATE 16 December 2016, half an hour after posting: Add The Atlantic to those accepting Derocher’s misinformation on WHB polar bear numbers without question, and failing to see that because patrols in Churchill were stepped up considerably after a serious mauling occurred in 2013 (because several bears got through their Halloween dragnet), more “problem” bears in Churchill since then only mean the Polar Bear Alert folks are doing their jobs.

But what does The Atlantic conclude, after talking to Derocher?

The Churchill bears…are probably doomed.

Never was a rational book on the science and conservation status of polar bears more desperately needed – it will be available soon.
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Western Hudson Bay polar bear numbers are stable, no trend in ice breakup or freeze-up

This needs saying again: the latest study on Western Hudson Bay polar bears reveal the population has been stable since 2004 and there has been no significant trend in either breakup or freeze-up dates since 2001.

Triplets in Wapusk NP from McCall webpage 2013

Environment Canada and the IUCN Polar Bear Specialist Group concur that the current size of the WHB subpopulation is about 1030 bears. Documents found online indicate a new version of the 2013 WHB mark-recapture report (Lunn et al. 2013) is now available (Lunn et al. 2014) and that a new population survey is planned for 2016. A 2013 story based on false information produced by The Guardian that is still in circulation should be retracted.
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Faux polar bear figures – my editorial in the National Post

Published in the Business section (Financial Post “Comments”) of the National Post this morning:

Paul J. Richards/AFP/Getty Images [NP story]

Paul J. Richards/AFP/Getty Images [from original NP essay]

“Faux polar bear figures” [not my choice of title, by the way]

In which I conclude:

We admire polar bear biologists for their professional dedication to this iconic species, and rightly so. However, while it’s understandable that polar bear biologists are conservation-minded, the public and policy makers need them to be scientists first and advocates for polar bear protection second. Polar bears are currently doing well – data shenanigans to keep them classified as “threatened” undermine the whole point of doing science.”

I have written extensively about the Southern Beaufort issue — below are links to some of these, which have links to the rest. References are included in these individual posts. Contact me if there is a reference you cannot find: Continue reading

Polar bear female with cubs fights off adult male – photos from W Hudson Bay

Discovery News ran a photo feature yesterday (January 28, 2014), courtesy Mike Lockhart from Polar Bears International, of an interesting incident Lockhart witnessed while was working with a government (Manitoba Conservation) research team surveying bears of Western Hudson Bay in the fall of 2013.

Figure 1. Female with 2 cubs turns on an adult male (far right) that she had been happily feeding with moments before. Mike Lockhart photo, Polar Bears International and Discovery News.

Figure 1. Female with 2 cubs turns on an adult male (far left) that she had been happily feeding with moments before. This is the 3rd photo in the sequence; see description and photo 4 below. Mike Lockhart photo, Polar Bears International, Discovery News story.

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