What presents a bigger risk to current polar bear populations: natural hazards that have already proven deadly or potential, yet-to-be-realized threats prophesied to occur due to human activities? That’s a perfect question for International Polar Bear Day.
Dag Vongraven, chair of the IUCN Polar Bear Specialist Group, remarked last year that “until 2001, everything was fine.”
Polar bear researchers thus assume that 2001 was the year climate change became the new over-hunting – but is it true? What are the relative harms presented by proven natural causes, potential human-caused threats, and predicted threats due to sea ice declines blamed on global warming? Considered objectively, is climate change really the single biggest threat to polar bear health and survival right now?
Posted in Advocacy, Conservation Status, Population, Summary
Tagged climate change, Derocher, endangered, extinction, facts, forecast, global warming, hazards, International Polar Bear Day, IUCN, natural causes, natural variability, over-hunting, poaching, polar bear, prediction, sea ice, snow, Stirling, threatened, threats, Vongraven
The other day, I got a call from an international journalist who admitted he’d done no research into the polar bear issue but believed, based on media reports he’d heard, that there must only be about 100-200 bears remaining in the Arctic. I know he’s not alone.
This journalist was utterly astonished to learn that the IUCN Red List assessment in 2015 put the polar bear population total at 22,000-31,000 bears and demanded proof that this was true.
Here is a summary of the Red List report, with references and links to the report:
The 2015 IUCN Red List assessment update for polar bears (published 18 November 2015) states that the global polar bear population is 22,000 – 31,000 (26,000), that the current trend is ‘unknown’ and that there is only a 70% chance that polar bear numbers will decline by 30% in 35 years (with virtually zero chance that the numbers will decline by 80% or more by 2050) – in other words, zero chance of extinction. [Detailed in a document called 22823 Ursus maritimus]. It classifies the polar bear as ‘vulnerable’ to extinction based on predictions of future sea ice decline due to global warming [similar to ‘threatened’ by other organizations] Pdf here.
Below is a list of what truly worrying species declines look like: that is, animals whose numbers have actually declined, no prophesies involved (Adler 2008).
Posted in Advocacy, Conservation Status, Population, Sea ice habitat
Tagged Amur tiger, climate change, decline, elephant seal, endangered, extinction, facts, fur seal, global warming, gray whale, hooded seal, IUCN, polar bear, predictions, projections, prophesy, rare species, Red list, sea ice, sea otter, Siberian tiger, status, Steller sea lion, threatened, vulnerable
The IUCN Polar Bear Specialist Group admits its global population estimate is simply a qualified guess with a large potential error. So perhaps it’s time to acknowledge that for the purpose of comparing polar bears to other species of concern, the upper limit for polar bear numbers worldwide could be more than 30,000?
See previous posts on this global population size issue (here and here); updated information below, including the most recent IUCN PBSG statement.
UPDATE 1 September 2015: here is an updated graph of polar bear population numbers that undo the “subtractions” of the PBSG between 2001 & 2013, giving a final global estimate of about 26,000. Click to enlarge:
UPDATE 25 November 2015: The 2015 update of the IUCN Red List for polar bears essentially concurs with my assessment about polar bear numbers. They estimate the current global population is 20,000-31,000 (average of 25,500, see below, without considering the number of bears in the Arctic Basin, so not far off my assessment) but say the trend in the population is “Unknown.”
UPDATE 23 February 2017: A new population estimate update is available based on three new survey counts that add about 2,000 bears to the average total, bringing it to almost 30,000 (28,500). Details here.
Posted in Conservation Status, Population
Tagged Amur tiger, endangered, IUCN, PBSG, polar bear, Polar Bears International, polarbearscience, population estimate, science, Siberian tiger, snow leopard, threatened, white rhino
More bad science: US biologists successfully used a scientifically flawed model to get polar bears listed as ‘threatened’ and thus emboldened, went on to do the same for walrus.
The intricate US Geological Survey model of ‘expert opinion’ that was used to support the listing of polar bears as ‘threatened’ under the US Endangered Species Act (ESA) has been soundly rejected by the world’s leading conservation organization, the IUCN,1 which has has tightened its rules for using “future conditions” (e.g., effects of global warming) in generating Red List assessments. That IUCN condemnation means the USGS model was never “the best available science” for evaluating the status of polar bears ̶ it was (and still is) substandard, inadequate science that makes a mockery of serious conservation efforts.
However, not only has this flawed model continued to be used by the USGS for polar bears, it has also been used to assess the conservation status of Pacific walrus, which are now officially “candidates” for being listed as ‘threatened’ (US Fish and Wildlife Service 2011).2
Posted in Advocacy, Conservation Status, Sea ice habitat, walrus
Tagged Amstrup, Bayesian Networks, best available science, conservation, endangered, ESA, IUCN, model, polar bear, threatened, US Fish and Wildlife Service, USGS, walrus
Well, sort of — what they did was provide a logical fallacy reply to an almost incoherent comment by a PBI Facebook supporter who had watched the documentary and complained of bias (such a predictable response).
See what you think, screen-cap below (taken September 3, 2014 at about 2PM Pacific Time.
[UPDATE added September 4, 2014 at 8:30PM Pacific, see below]
Posted in Advocacy, Conservation Status, Sea ice habitat
Tagged Derocher, documentary, endangered, Environment Canada, Facebook, IPCC, IUCN, logical fallacy, man behind the curtain, Polar Bear Specialist Group, polar bears, Polar Bears International, politics of polar bears, sport hunting, threatened, trophy bears
Umbrage alert! Last night, a half-length short form of the powerful and balanced documentary “The Politics of Polar Bears” aired across Canada on the CBC’s flagship TV news program, The National.
Right after it aired, they followed up with a lengthy online summary by the producer of the film, Reg Sherren (“Polar bears: Threatened species or political pawn?”, September 2, with video of the 19 minute short program). Check out the comments below it! Excerpts and my comments below.
[Links to the full length film here and in my previous posts here and here]
UPDATED April 27 2015: Video now available on Youtube, imbedded below Full length video no longer available, short one at CBC here.
Posted in Advocacy, Conservation Status, Population
Tagged CBC, Derocher, documentary, endangered, global warming, Mitch Taylor, polar bear, politics of polar bears, population estimate, predictions, Reg Sherren, sea ice, The National, threatened, video, warm interglacials, western hudson bay
The CBC in Canada is pretty much a mirror image of the BBC in the UK, ABC in Australia and PBS in the US. So you might appreciate my shock at the almost unbelievable balance contained in the recently broadcasted CBC documentary, “The Politics of Polar Bears: Tracking the Celebrity Bear.”
The film is a profound change from the hype and pessimism that has dominated the polar bear issue in Canada and abroad, supported unchallenged by the CBC. Finally, TV viewers were given some decently balanced perspective on the status of polar bears in Western Hudson Bay.
If the take-away message tipped towards reason and optimism rather than panic over the status of polar bears, it’s because the evidence was strongly in that direction.
Posted in Conservation Status, Population, Sea ice habitat
Tagged Churchill, declining sea ice, Derocher, endangered, he who must not be named, Mitch Taylor, PBSG, polar bear attack, polar bears, population estimate, qualified guess, sea ice models, Steve McIntyre, threatened, western hudson bay
“Our results suggest that mark–recapture estimates may have been negatively biased due to limited spatial sampling. We observed large numbers of bears summering in southeastern WH, an area not regularly sampled by mark–recapture.” Stapleton et al. 2014.
Polar bear at Wapusk National Park in August 2011. Courtesy Parks Canada.
We’ve seen the results of this 2011 study before, in government report format. But now it’s been revamped, peer-reviewed and published in a respected scientific journal – it actually came out in February, without fanfare, but I’ve only just come across it.
Some excerpts below, with conclusions that should raise some eyebrows.
Posted in Conservation Status, Population, Sea ice habitat
Tagged aerial survey, early breakup, endangered, invalid methods, later-than-average breakup, mark-recapture, polar bear, population estimate, Seth Stapleton, Southern Beaufort, Southern Hudson Bay, threatened, US Fish and Wildlife Service, Wapusk National Park, western hudson bay
In 2008, polar bears in the United States were declared ‘threatened’ under the Endangered Species Act (USFWS 2008). The IUCN (to which the Polar Bear Specialist Group (PBSG) belongs) lists the polar bear as “vulnerable” (IUCN Red List 2012). In Canada (where 60% of the world’s polar bears reside), the polar bear is listed as a ‘species of special concern’ (COSEWIC 2008:iii).
As Jonathan Adler pointed out in an excellent article that appeared on the heels of the American ESA listing decision (Adler 2008:112), “Insofar as the listing is based upon climate models, ice-melt projections, and assumptions about the effects of habitat loss on the bear’s prospects for survival in the wild, its scientific basis is quite speculative.” These are also, as I understand it, unprecedented criteria for ESA listing – no other species has been listed as endangered or threatened based on such speculation of future conditions.
So what do actual polar bear population declines look like?
The Western Hudson Bay, Canada (WHB) subpopulation is the only one that has recently declined by a statistically-significant amount. [see previous post here on the status numbers] The WHB polar bear subpopulation makes up 3-5% of the global total for the species, currently estimated at 20,000-25,000 animals.
In this post, I’ll compare the documented WHB population decline to the declines seen in a few truly endangered animals, just to put the much-bandied about numbers into some perspective. Continue reading