Monthly Archives: April 2013

Cannibalism update and insight on the timing of media hype

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. Continue reading

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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The two faces of polar bear biologists – Zac Unger interviews Amstrup and Stirling

Former firefighter Zac Unger has been in the news quite a lot over the last few months, promoting his new book, “Never Look a Polar Bear in the Eye” (see Zac’s website here, where you’ll find a list of some of the articles he’s written; the Canadian Geographic one is very good (“The truth about polar bears”) and was the one that originally caught my attention in early December 2012. One article that I’ve read is missing from that list, “Are Polar Bears Really Disappearing?” (Wall Street Journal, Feb. 8, 2013). There is a book review in the Winnipeg Free Press here (Feb. 2, 2013) and on climate scientist Judith Curry’s blog (Dec. 21, 2012), and an interview with Globe and Mail columnist Margaret Wente here from Feb. 23, 2013).

I’ve mentioned bits from some of these articles previously: Featured Quote #32 (Feb. 23, 2013) and in my Dec. 16, 2012 post, ‘Species-threatening’ population declines vs. polar bear declines.

In my last post, I promised a follow-up discussion on cannibalism in polar bears, as it has been promoted by polar bear biologists. I recalled a discussion of this by Unger, which I think makes a nice lead-in for my own essay, which I should have up in a few days.

Here is the money quote from Unger (with a link to the NBC interview with Amstrup and Stirling he is talking about). A lengthy excerpt from the article is below, for the context – it’s well worth a read:

[In 2008, after watching polar bear biologist Dr. Steve Amstrup give an interview on NBC News explaining “the evidence behind the decision to list the polar bear as threatened. Evidence like cannibalism.”] “Wait a second. Hadn’t Amstrup just finished telling me that the cannibalism thing was getting too much play by a bloodthirsty media?” Zac Unger, PS Magazine, Dec. 17, 2012 [2:40 min. NBC News video here]

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Collapse of polar bear snow dens – Stirling and Derocher’s anecdotal evidence

In their summary of facts supposedly supporting the premise that global warming is already having an impact on polar bear populations (discussed previously here, here, and here), biologists Ian Stirling and Andrew Derocher (2012:2700) include a list of incidents of warm winter weather and/or “rain on snow events” that have led to the collapse of polar bear maternity dens and ringed seal birthing lairs.

Stirling and Derocher state that both polar bears and ringed seals (their primary prey) have a demonstrated

high vulnerability …to increased mortatily resulting from warm temperatures and rain. Such rain on snow events are predicted to increase as the climate warms in the Arctic (Hansen et al. 2011).”[my bold]

However, their so-called evidence for polar bears and ringed seals having a proven vulnerability to these events comes not from scientific studies but what they admit outright are anecdotal reports.

They describe four incidents, including one case of a maternity den collapse (involving a 6 yr old, probably first-time mother and two, 3-4 week old cubs) in the southern Beaufort in 1989, apparently caused by a bit of warm weather followed by heavy snow in late January (a picture of the dead bear is included, see below, just so we don’t forget that a bear died).

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Misleading “State of the Polar Bear” graphic still not fixed

UPDATE FEBRUARY 19, 2014The misleading “State of the Polar Bear” graphic is now GONE (as of January 31, 2014). A new 2013 status table is offered by the PBSG here. It has detailed text explanations and harvest information, with references, hyperlinked to each subpopulation entry (“Press the subpopulation hyperlink and more information will appear“) and may have replaced the “State of the Polar Bear” graphic that the PBSG commissioned for upwards of US$50,000, although the PBSG website says it is being “updated [A pdf copy of the 2013 colour table is here, and my commentary on it is here.] I have left the original post as is, below.

This is an update regarding the IUCN Polar Bear Specialist Group (PBSG)’s fancy, multilevel State of the Polar Bear web graphic that I discussed previously here, here, and here.

To refresh your memory, two points about this graphic stand out, both regarding polar bear population estimates:

1) The population estimates listed on the Nations map (copied below) add up to 22,600-32,000 – far higher than the official estimate of 20,000-25,000 polar bears worldwide.

2) The population estimates listed on the upper layer of the Subpopulation map add up to just 13,036 – not even close to the official estimate of 20,000-25,000 polar bears worldwide.
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