Large margins of error in polar bear population estimates means the conservation status threshold of a 30% decline (real or predicted) used by the US Endangered Species Act and the IUCN Red List is probably not valid for this species.
Several recent subpopulation estimates have shown an increase between one estimate and another of greater than 30% yet deemed not to be statistacally significant due to large margins of error. How can such estimates be used to assess whether population numbers have declined enough to warrant IUCN Red List or ESA protection?
What do polar bear population numbers mean for conservation status, if anything?
Posted in Conservation Status, Population
Tagged baffin bay, declining, Derocher, errors, ESA, estimate, facts, IUCN Red List, numbers, polar bear, population, science, significance, statistics, Svalbard, western hudson bay
Polar bear specialists Andrew Derocher and Steven Amstrup recently spent inordinate energy trying to refute the opinion piece I’d written for the Financial Post in celebration of International Polar Bear Day last month, ignoring my fully referenced State of the Polar Bear Report for 2017 that was released the same day (Crockford 2018) and the scientific manuscript I’d posted last year at PeerJ Preprints (Crockford 2017).
Their responses use misdirection and strawman arguments to make points. Such an approach would not work with the scientific community in a public review of my paper at PeerJ, but it’s perfect spin for the self-proclaimed “fact-checking” organization called Climate Feedback. The result is a wildly ineffective rebuttal of my scientific conclusion that Amstrup’s 2007 polar bear survival model has failed miserably.
This is Part 2 of my expose, see Part 1 here.
Posted in Conservation Status, Population, Sea ice habitat, Summary
Tagged Amstrup, bearded seal, Beaufort, Chukchi Sea, Climate Feedback, damage control, Derocher, ESA, fact checker, failed predictions, ice-free, observations, polar bear, predictions, ringed seal, sea ice, spin, spring, Stirling, summer, survival, thick ice, threatened
It’s been more than a year since I first published my scientific manuscript at PeerJ Preprints (a legitimate scientific forum) on the failure of Amstrup’s 2007 USGS polar bear survival model (Crockford 2017), a year waiting in vain for the polar bear community to comment. They either couldn’t be bothered or knew they couldn’t refute it – I haven’t known for sure which. But I do now.
Polar bear specialists didn’t comment because they couldn’t refute it in the scholarly manner required by PeerJ: all they could do is tear it down with derision, misdirection and strawman arguments.
I know this because the damage control team for the polar-bears-are-all-going-to-die-unless-we-stop-using-fossil-fuels message wasn’t activated over my fully-referenced State of the Polar Bear Report for 2017 (Crockford 2018) released on International Polar Bear Day last month, but for a widely-read opinion piece I’d written for the Financial Post published the same day (based on the Report) that generated three follow-up radio interviews.
By choosing to respond to my op-ed rather than the Report or my 2017 paper, biologists Andrew Derocher and Steven Amstrup, on behalf of their polar bear specialist colleagues1, display a perverse desire to control the public narrative rather than ensure sound science prevails. Their scientifically weak “analysis” of my op-ed (2 March 2018), published by Climate Feedback (self-proclaimed “fact checkers”), attempts damage control for their message and makes attacks on my integrity. However, a scientific refutation of the premise of my 2017 paper, or The State of the Polar Bear Report 2017, it is not (Crockford 2017, 2018).
Derocher further embarrasses himself by repeating the ridiculous claim that global polar bear population estimates were never meant for scientific use, then reiterates the message with added emphasis on twitter:
Just as the badly written Harvey et al. (2017) Bioscience paper said more about the naked desperation of the authors than it did about me or my fellow bloggers, this attempt by the polar bear community’s loudest bulldogs to discredit me and my work reveals their frustration at being unable to refute my scientifically supported conclusion that Amstrup’s 2007 polar bear survival model has failed miserably (Crockford 2017).
Part 1 of my detailed, fully referenced responses to their “analysis” of my op-ed are below. Part 2 to follow [here]. Continue reading
Posted in Conservation Status, Scientists hit back, Sea ice habitat, Summary
Tagged Amstrup, critique, damage control, Derocher, endangered, ESA, fact checker, facts, feedback, polar bear, predictions, sea ice, spin, State of the Polar Bear, threatened, USGS
The administrative reports used in 2007 to support the decision to list polar bears as ‘threatened’ under the US Endangered Species Act (ESA) in 2008 disappeared from the US Geological Survey website several years ago. I have archived them here in pdf format to make them easy to find for anyone wishing to access the accuracy of the models, data, and assumptions made in 2007.
Steven Amstrup in 2005, then lead USGS polar bear biologist, with triplet cubs, Prudhoe Bay, AK.
This is a housekeeping post meant for future reference. I’ve included citations for the relevant sea ice projection papers used in the models presented in the 2007 documents and a few other related reports from the same time period. Continue reading
Posted in Conservation Status, Sea ice habitat
Tagged ACIA, Administrative report, Amstrup, Beaufort Sea, Bergen, DeWeaver, Durner, ESA, Executive Summary, Hassol, Holland, Hunter, listing decision, Obbard, polar bear, projections, Regher, Rode, Schliebe, Science Strategy to Support, sea ice, Solomon, Stirling, US Fish and Wildlife Service, us geological survey, USGS, Zhang
In early October, the US Fish & Wildlife Service reversed its 2011 decision to list Pacific walrus as ‘threatened with extinction’, saying they could not “determine with certainty that walruses are likely to become endangered “in the foreseeable future.” [details below]
I have argued that the 2008 decision by the USFWS to list polar bears as ‘threatened’ is similarly lacking in certainty (Crockford 2017) and as for walrus, the previous determination of ‘threatened’ for polar bears was premature and should be reversed.
A prominent biology colleague and I recently put it this way in a newly published essay:
“Is it ethical or fair to the many citizens impacted directly and indirectly by the 2008 polar bear ruling for the FWS to allow polar bears to remain on the Endangered Species List?”
Read our piece in the winter 2018 issue of RANGE Magazine (open access), authored by myself and Dr. Valerius Geist, professor emeritus of environmental science at the University of Calgary, Alberta.
Crockford, S.J. and Geist, V. 2018. Conservation Fiasco. Range Magazine, Winter 2017/2018, pg. 26-27. Pdf here.
PS. You’ll find an excellent piece on wildfires by biologist Jim Steele in the same issue.
See also Crockford, S.J. 2017. Testing the hypothesis that routine sea ice coverage of 3-5 mkm2 results in a greater than 30% decline in population size of polar bears (Ursus maritimus). PeerJ Preprints 2 March 2017. Doi: 10.7287/peerj.preprints.2737v3 Open access. https://doi.org/10.7287/peerj.preprints.2737v3
Details on the USFWS decision on the walrus is below. Note that like the walrus, if ESA protection on the polar bear was reversed, the bears would still be strongly protected under the Marine Mammal Protection Act (as they have been since 1972), and like the walrus, polar bears have shown an ability to adapt that was not foreseen in 2007 (as evidenced by their failure to die off droves in response to recent sea ice declines).
Posted in Conservation Status, Sea ice habitat, walrus
Tagged conservation, endangered, ESA, essay, global warming, polar bear, sea ice loss, threatened, USFWS, 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).
Posted in Advocacy, Population, walrus
Tagged conservation, ESA, estimates, ethics, journalist, polar bear, population, scientist, sea ice, status, threatened, USFWS, walrus, western hudson bay
“U.S. Fish and Wildlife Service officials said they cannot determine with certainty that walruses are likely to become endangered “in the foreseeable future,” which the agency defines as the year 2060.”
(CBC, 4 October 2017).
“The agency said in 2011 that walruses deserve the additional protection of being declared threatened, but delayed a listing because other species were a higher priority.
The agency revised the decision based on new information, said Patrick Lemons, the agency’s marine mammals management chief.
“Walrus demonstrated much more ability to change their behaviours than previously thought,” Lemons said. Their ability to rest on shorelines before swimming to foraging areas makes the threat of less sea ice uncertain, he added.”