In my last post, I went over some of the spin and misrepresentation of fact contained in the claim by leading polar bear biologists Steven Amstrup, Ian Stirling and Andrew Derocher (Amstrup et al. 2006; Stirling and Derocher 2012) that cannibalism is on the increase because of the effects of global warming on Arctic sea ice.
I’ve had an opportunity to follow up on three points that puzzled me. Three relate to the Amstrup et al. paper that described three cases of cannibalism in the southeastern Beaufort Sea in 2004 and one to the incidents in western Hudson Bay in 2009. In the process, I found at least three more misrepresentations of fact and gained some insight on why these incidents of cannibalism were hyped so enthusiastically when they were.
The Amstrup/Beaufort incidents (2004, reported 2006)
Sifting through more online news reports of the Beaufort cannibalism events from 2004 that Amstrup and colleagues described in 2006, I found this article: “It’s a bear-eat-bear world as climate changes: “Biologists count three cases of cannibalism in Beaufort Sea” from Nunatsiaq News (June 16, 2006; Jane George). In it there is this statement:
“The biologists admit that a single rogue polar bear, with a taste for his own kind, could have been responsible for the three incidents.” [my bold]
Funny, while that admission was made in the published paper, no other news report picked up on it, that I saw. Perhaps that’s because the journalist at the Nunatsiaq News knew it was pertinent and made sure to include it, while non-Arctic reporters did not.
But given that two of the three incidents described took place within days of each other (April 7 and April 10 – both near Herschel Island, Canada), and the other occurred 350 km or so west and several months before (January 24, just west of Prudhoe Bay, Alaska), a single rogue bear in the area indeed seems a plausible explanation – if not the most probable.
Here is exactly what Amstrup et al. (2006:5) said in their conclusions:
“The underlying causes for our cannibalism observations are not known. They simply could be chance observations of previously unobserved rare events, or even a single rogue male bear that adopted a survival strategy including cannibalism. Because we have not observed such events previously, however, we cannot overlook the possibility they may be related to the generally poorer condition we recorded for polar bears in the Southern Beaufort Sea compared to bears in adjacent areas to the north and west.” [my bold]
But the sentence that followed also caught my attention:
“Because adult male polar bears feed little during the spring when they focus on breeding, they enter summer in poor condition (Amstrup 2003). Therefore, adult males may be the first population segment to show adverse effects of the large ice retreats of recent years…” [my bold]
While it may be true that male polar bears may be too preoccupied during the mating season to eat much for a few weeks, I’ve never seen it put quite like that before. In other words, I’ve never seen that claim before. The reference provided for this statement [Amstrup 2003] is an encyclopedia-type summary of polar bear biology in a book called Wild Mammals of North America, not an original research report.
So I checked the 2003 edition of Wild Mammals of North America out of the library and read through the entire chapter on polar bears.
And guess what I found? No mention at all of a phenomenon whereby adult males feed little during the spring when they focus on breeding, or that they enter summer in poor condition.
It appears then that the claim made in the the Amstrup et al. paper that male polar bears are particularly at risk for cannibalism is not based on fact. That makes one clear misrepresentation of fact for this paper.
However, I did find something else interesting in Amstrup’s chapter on polar bears, at odds with his claim, quoted by the media, that he’d never seen a starving polar bear before the spring of 2004 (backup here).
Imagine my surprise to find this statement in the chapter on polar bears in Wild Mammals of North America written by Amstrup himself (2003:602):
“Starvation of independent young as well as very old animals must account for much of the natural mortality among polar bears… Also, age structure data show that subadults aged 2-5years survive at lower rates than adults (Amstrup 1995), probably because they are still learning hunting and survival skills.”
“I once observed a 3-year-old subadult that weighed only 70 kg in November. This was near the end of the autumn period in which Beaufort Sea bears reach their peak weights (Durner and Amstrup 1996), and his cohorts at that time weighed in excess of 200 kg. This young animal apparently had not learned the skills needed to survive and was starving to death.”[my bold]
So, subadult bears succumb rather often to starvation! Could it be that subadults made up most of the bears Amstrup and colleagues found in ‘lean’ condition in 2004?
We don’t know, because all they say is that “70 of 148 (47%) of bears captured as independent animals (i.e., not including cubs captured with their mothers) were in the lean condition classes 1 and 2.” No mention of age.
I call that one more misrepresentation of fact for this paper, for a total of two.
The Stirling-Derocher/Hudson Bay incidents (2009, reported 2009)
An astute reader of my last post commented to me that the eight incidents reported to occur in 2009 in western Hudson Bay by Stirling and Derocher (2012:2701 – “there were eight observations of cannibalism on the western coast of Hudson Bay,” see previous post here) sounded more like four incidents reported twice.
For example, the CBC news reports stated: “Four cases were reported to Manitoba Conservation and four to Environment Canada.” Hungry polar bears resorting to cannibalism” Thursday, December 3, 2009, CBC News. Backup here. [Churchill is in the province of Manitoba and would keep provincial records; Environment Canada is the federal agency that would also keep such a report on file]
However, the Polar Bears International press release (Nov. 27, 2009) – which was the source for all media information – actually says four (pdf here) and gives these details:
In addition, photographer Daniel J. Cox – who took many of the photos and the video footage released to the media, said on his blog [backup here]:
“It’s documented that this year in the Churchill region there have been four instances of male polar bears preying on cubs.”
So, I have to agree – that sounds like four incidents to me, not eight. And unless someone can produce a document showing that there were actually eight incidents of cannibalism in 2009, that makes four misrepresentations of fact in the Stirling and Derocher 2012 paper about cannibalism, not three (as detailed in my last post).
The oh-so convenient timing of the cannibalism hype
Amstrup and the ESA petition: By 2005, the Center for Biological Diversity (CDC) had filed a petition to have polar bears declared ‘threatened’ under the US Endangered Species Act. And given the global warming spin put on the 2004 Beaufort Sea incidents by Amstrup in his interviews with the media, it had to happen: a journalist at the Washington Post (Dan Joling, June 12, 2006) turned to the CDC for a comment. This is what the journalist reported:
“Cannibalism demonstrates the effect on bears, said Kassie Siegal, lead author of the petition.
“It’s very important new information,” she said. “It shows in a really graphic way how severe the problem of global warming is for polar bears.”
Deborah Williams of Alaska Conservation Solutions, a group aimed at pursuing solutions for climate change, said the study represents the “bloody fingerprints” of global warming.” [my bold]
So, given how the backers of the ESA petition felt about cannibalism after all the media hype in 2006, would it emerge as another documented impact of global warming on polar bears in the final ESA ruling?
Indeed it did: in the final ESA ruling issued in 2008 (pdf here), cannibalism is listed as a specific concern – even though the claim was based totally on three anecdotal reports and no baseline studies existed with which to compare those incidents.
Stirling and the UN Climate Change Conference: As one Dec. 8 2009 news report noted regarding the photos and video footage of the Hudson Bay polar bear consuming a cub:
“The release of the images comes as world leaders gather in Copenhagen for the United Nations Climate Change Conference.”
So, it seems that the imminent 2009 Climate Conference in Copenhagen in December could have been one reason why the incidents of cannibalism in western Hudson Bay were hyped so extensively. It would explain why Polar Bears International went to all the trouble to issue a press release, on November 27, to draw the world’s attention to it – the UN conference ran Dec. 7-18 and many cannibalism stories ran during the first week of December. The timing might also explain why four documented cases somehow morphed into eight: climate change proponents needed an emotion-laden issue, with gut-wrenching pictures, to help support their cause (and eight sounds like more of an increase than four).
Stirling-Derocher and the 2013 CITES meeting: And the 2012 paper by Stirling and Derocher, with FOUR misrepresentations of facts on cannibalism (on top of the “sea ice tricks” discussed here)? Was there convenient timing there as well?
Indeed there was. The paper was released without much fanfare a few months prior to the 2013 meeting of CITES, when the US Fish & Wildlife Department and several advocate groups were lobbying hard to have all international polar bear trade banned (see previous posts here and here). And it would be naive not to point out that the Stirling and Derocher paper was also published in time to be included in the next IPCC report (AR5), due later this year. Not so much hype but certainly a paper intended to be used as a supporting document for the claim that global warming is already having a negative effect on polar bear populations, which we now know contains many misrepresentations of fact.
In summary, by 2006, because of the hype generated over the Amstrup et al. paper on the Beaufort Sea cases, polar bear cannibalism was firmly accepted as an early manifestation of the horrors of global warming. Only one person may have actually said that cannibalism represented “the bloody fingerprints of global warming” but that is how it was used by the media and environmentalists. This strategy of hyping cannibalism in the media was shown to be effective in garnering the kind of emotional response that global warming advocates like Polar Bears International were seeking to support their cause – so they used it again in 2009.
Amstrup, S.C. 2003. Polar bear (Ursus maritimus). In Wild Mammals of North America, G.A. Feldhamer, B.C. Thompson and J.A. Chapman (eds), pg. 587-610. Johns Hopkins University Press, Baltimore.
Amstrup, S.C., Stirling, I., Smith, T.S., Perham, C. and Thiemann, B.W. 2006. Recent observations of intraspecific predation and cannibalism among polar bears in the Southern Beaufort Sea. Polar Biology 29, no. 11:997–1002. Pdf here.
Stirling, I. and Derocher, A.E. 2012. Effects of climate warming on polar bears: a review of the evidence. Global Change Biology 18:2694-2706. doi:10.1111/j.1365-2486.2012.02753.x
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