Daily Archives: April 10, 2013

Cannibalism in polar bears: spin and misrepresentation of fact galore

In my next to last post, I discussed some of the anecdotal reports of den collapses included in the peer-reviewed summary of facts presented by biologists Ian Stirling and Andrew Derocher (2012) that supposedly support the premise that global warming is already having an impact on polar bear populations (discussed previously here, here, and here), prophesied to be even greater in the future. While they admit that such reports are not based on scientific studies, they nevertheless include them in their published list of global warming impacts, and not surprisingly, that is how others have interpreted them.

The same is true for their treatment of the phenomenon of cannibalism in polar bears. In that same paper, Stirling and Derocher (2012:2701) have a section called “Anecdotal observations consistent with predictions of the effects of climate warming.” This section begins with a discussion of cannibalism:

“There have been several well-publicized observations that are consistent with predictions of the effects of climate warming on polar bears, but cannot be statistically linked. For example, intraspecific aggression and cannibalism were predicted to increase in polar bears with climate warming (Derocher et al. 2004, Table 1). Observations of infanticide and cannibalism by thin adult males on land during the open water period have been documented (e.g., Lunn & Stenhouse, 1985; Derocher & Wiig, 1999; Amstrup et al., 2006; Stone & Derocher 2007). Such events have been known to occur for many years and, although their significance is unclear, there is some evidence suggesting the frequency of occurrence is increasing in areas where bears fast on land for extended periods. ” [my bold]

And this is the evidence for the supposed increase in occurrence:

“For example, in late summer and autumn 2010 [sic], there were eight observations of cannibalism on the western coast of Hudson Bay compared to one or two in the previous 5 years (I. Stirling, unpublished data).” [my bold; 2010 should be 2009 – more on this later.]

Were these observations of cannibalism made by polar bear researchers or someone else? Were there as many observers in the area in each of the five years prior to the year they occurred, as there were when these incidents were observed? We don’t know, because it’s unpublished data.

Stirling and Derocher have again included critical information in their list of facts that has not been published. I guess I’ll have to add “evidence for cannibalism” to my previous list of “Critical evidence on polar bears in W. Hudson Bay is unpublished” (see also “Stirling and Derocher’s sea ice trick) [there is more information available, but it’s not from peer-reviewed sources – more on this below]

In this post, I take a look at some of the evidence that is published, some of the media interviews and reports that followed, and the information that came from a press release issued by an advocate group. I’ve made a table summarizing the details of all recent papers and reported incidents, and some of them are described in more detail. In a footnote, I have a brief summary of why polar bears kill and eat each other.

These details reveal some rather shocking evidence of scientists misrepresenting evidence – in their peer-reviewed papers and in interviews with the media – and bathing their global warming prophesies in the blood-lust of cannibalism. It’s past time to shine a big bright light on the cannibal issue, so pardon the length of this post.

[See followup post April 19 here]

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