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.
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):
Quotes, map, and table from the Dyck et al. 2017 report (pdf here) are copied below.
Posted in Conservation Status, Population, Sea ice habitat
Tagged decline, Derocher, estimate, extirpated, facts, increasing, polar bear, population, significant, size, slight, stable, statistics, status, survey, western hudson bay
Comparing Churchill problem bear statistics over a few years provides some critical perspective: this year, the bears are causing much fewer problems.
This 2nd week in September is no exception, being the 9th week ashore in all cases: 2017 (4-10 September, where I think “total number of polar bear occurrence reports to date” should be 64, not 53, see week 7 report here), 2016 (5-11 September), 2015 (7-13 September), where there were about 1/2 the number of bears in “jail” this year compared to the last two years (i. e., 6 vs. 11 and 12) and slightly more than 1/2 the number of occurrence reports in 2017 than in 2016 and 2015 (64 vs. 107 and 99):
Now that all bears are ashore for the season, the folks at the Polar Bear Alert program in Churchill note in their report for week 7 (21-27 August, 2017) that the bears ashore are in excellent condition (confirming reports on the first bears ashore in July):
Rather marked contrast to the pessimistic spin on conditions from the field a few months ago:
[yes, a few bears fail to make it through the winter, especially young bears; but that has always been the case — it’s not a sign of human-caused global warming catastrophe]
Last week’s problem bear report also confirmed news from the Churchill Polar Bears website a few weeks ago that showed several images of very fat bears:
See below for last year’s report for week 7 and this year’s report for week 8 (28 August-3 September). Western Hudson Bay polar bears that come ashore near Churchill, Manitoba are starting their third month on land this week, out of the five months or so they have spent ashore in recent years (about 3 weeks more than in the 1980s, no longer than they did in 2004 — conditions have not been getting worse).
Posted in Life History, Sea ice habitat
Tagged alert, Churchill, Hudson Bay, ice-free, onshore, polar bear, problem bears, sea ice, summer, western hudson bay
Churchill, Manitoba Polar Bear Alert Program problem bear reports for weeks 3 (24 July – 30 July 2017) and 4 (31 July – 6 August 2017) show much less activity and fewer problems in this Western Hudson Bay location than were reported for the last two years (2016 and 2015) at the same time (relative to the first reports of the season):
Compare 2017 to last year (2016) at this time, where the problem bear report claims numbers were similar to 2015 (for which I don’t have a week 4 report), with more bears handled and placed in “jail”:
But most Western Hudson Bay bears are at their highest body weight when they come off the ice in early summer and present little risk to humans who keep their distance — few bears cause any real problems this time of year. Compare the above problem bear reports to the blog post from Seal River Lodge, just north of Churchill (5 August 2017, from Churchill Wild Eco-Lodge), which reports seeing 11 bears in one day of viewing. Great photos at this post confirm those bears are in good physical condition and interacting with each other without bothering people.
Just out from the City of Churchill: few polar bears reported onshore for the week of 17-23 July 2017 (week 2) but those seen “appear to be in great shape.”
Update 24 July 2017 12:20 PM: Just spotted this blog report from “Churchill Polar Bears” that I somehow missed last week, which includes what seems to be the first polar bear photo’s of the season (of a sow and two chubby cubs) that are also in fine condition.
The photos were taken by Churchill photographer and guide Alex De Vries on Thursday 13 July and I hope he doesn’t mind my including one of those here as documentary evidence of the good body condition of this mother and both her cubs — see more photos at the Churchill Polar Bears blog post dated 14 July here.
Compare last week’s PB Alert report above to last year’s (below):
The first activity report of the Churchill Polar Bear Alert Program has been released for 2017. It comes on the same week as last year’s (so about the same dates for first bears ashore both years), and reports pretty much the same activity.
Odd that this year’s report contains no mention whatsoever of the condition of the bears as did last year’s (see below), which may have brought criticism for spoiling the media ‘message’ that WHB bears are suffering because of reduced sea ice. Better no comment at all than good news, eh?
Sea ice for the week of 10 July off Western Hudson Bay this year consisted of a broad strip of thick first year ice (>1.2m thick) just off shore.
The ice charted above looked like this on a standard ice map:
There are no other reports that I could find of polar bears ashore along the coast of Western Hudson Bay, so these bears must be the first wave.