The Chukchi Sea finally has a polar bear population estimate! According to survey results from 2016 only recently made public, about 2937 bears (1522-5944) currently inhabit the region, making this the largest subpopulation in the Arctic. This is exciting news — and a huge accomplishment — but the US Fish and Wildlife Service responsible for the work has been oddly mum on the topic.
Not only that, but an extrapolation of that estimate calculated by USFWS researchers for Chukchi plus Alaska (the US portion of the Southern Beaufort Sea subpopulation) was estimated at 4437 (2283-9527), although with “significant uncertainty.” Nevertheless, it means the 2016 estimate for Alaska could be roughly three times what it was in 2010: a whopping 1500 or so, up from about 450 (or about 225-650) for the same area estimated during the last survey (Bromaghin et al. 2015: Fig. 5a).
Even if the real number for Alaska is only twice as large (~1000), that’s still a huge improvement. It would eliminate the Southern Beaufort as the only polar bear subpopulation in the Arctic to have shown a significant decline blamed on human-caused global warming (Crockford 2018). If the recovery is real, it means the 2004-2006 decline was a temporary fluctuation after all, just like previous declines in the region. I expect, however, that it will take a dedicated SB population survey for officials to concede that point.
not yet now a detailed report to cite (Regehr et al. 2018 in prep, see update below), but the numbers were announced at the 10th meeting of the Russian-American Commission on Polar Bears held at the end of July this year (AC SWG 2018) by Eric Regehr (formerly of the US Fish & Wildlife Service, as of 2017 at the University of Washington). [h/t to G.H.] This was the same report that raised the quota for subsistence hunting in the Chukchi from 58 to 85, based on these new figures, as I discussed last week.
From “Military bases to open on Wrangel Island and Chukotka” 22 October 2015.
Regehr was quoted as saying:
“Chukchi bears remain larger and fatter and have not seen downward trends in cub production and survival, according to new preliminary information on the health and numbers of bears.”
UPDATE 15 November 2018: The scientific paper describing the entirely new method (yes, yet another one: see Bromaghin et al. 2015) used to estimate the size of the Chukchi Sea population is now available (University of Washington press release here), in an open-access paper: Regher et al. 2018. News reports (see one here) spin the positive outcome as something that researchers expected all along but that’s simply not true. They expected Chukchi Sea bears and Southern Beaufort Sea bears to respond similarly to reduced amounts of summer sea ice, as explained here and in Crockford 2017).
Posted in Conservation Status, Population
Tagged Alaska, body condition, Chukchi Sea, cub survival, fat bears, guesstimate, healthy, increase, polar bear, population, Regehr, sea ice, Southern Beaufort, thriving, triplets
This year’s baseless media frenzy over walrus survival and loss of summer sea ice blamed on human-caused global warming was initiated by a press release from US Fish and Wildlife last week (16 August 2017, pdf here: “Pacific walruses haul out near Point Lay earlier than in previous years“). Quote below, my bold:
In the first week of August, several hundred Pacific walruses were observed on a barrier island near the Native Village of Point Lay, a small, Iñupiaq community on the northwest coast of Alaska. This is the earliest date yet for the haulout to form…This year, sea ice has retreated beyond the continental shelf earlier than in previous years
But is this all true? In a word, no — and it didn’t take much research to uncover the truth.
UPDATE 24 August 2017: A few minutes after this post was published, I became aware that just yesterday, 20 conservation activist organizations, lead by the Center for Biological Diversity (who led the polar bear listing charge) issued a press release regarding a letter (pdf here) pressuring the US Fish and Wildlife Service to list Pacific walrus as threatened or endangered under the Endangered Species Act. Apparently, a decision must be made by the end of September on whether to actively list walrus or not. The text below has been amended to reflect this development.
Posted in Advocacy, Conservation Status, Summary, walrus
Tagged Alaska, Chukchi Sea, climate change, earliest, endangered, ESA, fact check, facts, global warming, haulout, hype, Point Lay, sea ice, summary, US Fish and Wildlife Service, video, walrus
The newest polar bear science paper making the rounds courtesy the US Geological Survey, is a perfect example of a statistically-significant result with no biological significance. While the results are rather lame, the paper is dangerous because it repeats the disingenuous claim (see Crockford 2017) that Southern Beaufort Sea polar bear numbers declined in recent years due to summer sea ice loss.
The USGS authors (Durner et al. 2017) know this harm-from-summer-ice-loss assertion is not true for the Southern Beaufort subpopulation but the more papers they can get into print that say so, the more likely it will be believed — and the less likely readers will check older literature that documents the recent decline in polar bear numbers was due to a three year period (2004-2006) when thick ice conditions in spring made seal hunting a challenge, a repeat of a well-known phenomenon (e.g. Stirling et al. 1980; Stirling 2002) unique to this region that has been documented since the 1960s.
The Durner paper (USGS press release “Increased Sea Ice Drift Puts Polar Bears on Faster Moving Treadmill” published online 6 June ahead of print) spins the research results as potentially significant bad news but in so doing reveals how desperate they have become to make the public and their biology colleagues believe that Southern Beaufort polar bears, among others, are being negatively affected by summer sea ice loss (as per Stirling and Derocher 2012).
Durner, G.M., Douglas, D.C., Albeke, S.E., Whiteman, J.P., Amstrup, S.C., Richardson, E., Wilson, R.R. and Ben-David, M. 2017. Increased Arctic sea ice drift alters adult female polar bear movements and energetics. Global Change Biology. DOI: 10.1111/gcb.13746 http://onlinelibrary.wiley.com/doi/10.1111/gcb.13746/abstract [paywalled]
In fact, the Durner et al. paper does not document any harm to polar bears from the proposed ‘treadmill’ effect of more rapidly moving ice for the period 1999-2013 compared to 1987-1998, but instead uses models to suggest bears might have to eat one to three more seals per year to compensate for the extra energy needed to walk against the moving ice. That’s right: perhaps only 1 more seal per year out of the 50 or so they would usually consume (see Stirling and Øritsland 1995). In my opinion, that’s a pretty lame result for what one of the co-authors described as an immense amount of work.
News outlets have essentially used the USGS press release as a click-bait lede for another round of Trump-bashing with respect to the Paris climate change agreement, see here and here: the stories are hardly about polar bears at all. And predictably, polar bear activist and co-author Steven Amstrup (paid spokesperson for Polar Bears International, famous for their “Save Our Sea Ice” campaign) appears to be using the same approach: an up-coming call-in talk radio program at NPR’s Anchorage affiliate KSKA for Tuesday 13 June at 10:00 (Alaska time, see “Talk of Alaska”) is being billed as a discussion of “polar bears, climate change, and the Paris Accord” (h/t AK geologist). Continue reading
Posted in Advocacy, Conservation Status, Life History, Sea ice habitat
Tagged Alaska, Amstrup, Durner, endangered, energy, loss of summer ice, moving sea ice, polar bear, population decline, sea ice, seals, Southern Beaufort, spring feeding, summer sea ice, thick spring ice, threatened, treadmill, USGS
Two out of three polar bear females that were collared by USGS researchers near Barrow, Alaska last spring are hanging out on the northwest coast of Banks Island, Canada. The other bear (bright green icon) appears to have been collared on the ice off Prudoe Bay in April. And as I discussed last month, it’s unusual for bears from the western end of the Southern Beaufort subpopulation (or even the central region) to end up in the Northern Beaufort subpopulation territory.
Original caption: “Movements of 3 satellite-tagged polar bears for the month of October, 2016. Polar bears were tagged in 2016 on the spring-time sea ice of the southern Beaufort Sea. All 3 of these bears have satellite collar transmitters. Polar bear satellite telemetry data are shown with AMSR2 remotely-sensed ice coverage from 29 October, 2016.” See full resolution image here and close-up below.
Posted in Life History, Sea ice habitat
Tagged Alaska, Beaufort, denning, facts, females, freeze-up, ice growth, polar bear, satellite collars, sea ice, subpopulation boundaries, tracking, USGS
It appears that the male polar bear with a too-tight satellite radio collar that was photographed late last year near Kaktovik on the North Slope of Alaska has been captured and his faulty collar removed, says a statement posted on the University of Alberta website 25 August 2016. The animal was reported to be healthy and behaving normally.
As far as I can tell, no press release was issued and no media interviews have been conducted despite the strong interest in the fate of this bear last fall (previous reports here, here, and here) – I found the notice by accident while looking for something else.
Andrew Derocher and his research team from U of A have admitted they collared this bear and the Polar Bear Facts webpage where this recent statement appears was developed to deal with the many inquiries about the status of this bear (dubbed “Andy” by some).
Note the statement, copied below, does not confirm that this is indeed the same bear as was photographed last year – they just assume it is. No photo is provided of the rescued bear, although clearly some were taken. However, if it is not the same bear, then another subadult male spent the winter of 2015-2016 on the ice of the Beaufort Sea with a tight and non-functioning collar that was not about to fall off by itself.
Walrus researchers from the US Geological Survey have a new report on the history of walrus haulouts in the Chukchi and Bering Seas – yet their media efforts (via press release and interviews) fail to mention the relationship between fluctuating size of walrus haulouts and fluctuating walrus population size that is evident in that history. In fact, overall population size is not mentioned at all.
Two articles came out over the weekend that announced the results of this new joint US-Russian initiative [PBS, Walrus beaching in Alaska might not be as harmful as it looks. Here’s why – 31 July 2016 and ADN, Alaska and Russia join forces to create 160-year database of walrus haulouts – 31 July 2016]
But neither articles nor the new USGS paper they are touting (Fischback et al. 2016) mention the huge summer/fall haulouts of females, calves, and juveniles that were documented in the 1970s that coincided with the huge population size at that time, which crashed in the 1980s.
Only now has the population grown (to at least 200,000) to the point that huge haulouts are again being reported – conservation has done it’s job. But when walrus numbers get too high the animals out-strip their food source and numbers plummet, as they did in the 1980s (Fay et al. 1989; Garlich-Miller et al. 2011). See my fully referenced summary paper, Crockford 2014 (On The Beach: Walrus Haulouts are Nothing New).
Here’s the concern: When (not if) a population crash happens again, will it be blamed on global warming rather than natural causes? According to the PBS article:
“The database is supposed to help federal officials with conservation, especially as more ships start sailing through the newly open waters. The U.S. Fish and Wildlife Service is determining whether walrus should be listed as a threatened species.” [my bold]
My GWPF video on the issue (The Walrus Fuss) below:
See excerpts from the USGS database below, with a map:
Posted in Advocacy, Conservation Status, Sea ice habitat, walrus
Tagged Alaska, beaching, Bering Sea, change, Chukchi Sea, facts, Fischbach, global warming, GWPF, haul out, haulout, history, Point Lay, population size, report, St. Lawrence Island, threatened, USGS, video, walrus, Walrus Fuss