Tag Archives: misdirection

Biologists spreading misinformation: hybridization with grizzlies not due to polar bears moving inland

A paper published last week in the journal Science, written by a team of biologists and atmospheric scientists, expounds on a possible dire future for a range of Arctic animals. It’s called, “Ecological consequences of sea-ice decline” and surprisingly, polar bears are discussed only briefly.

However, with the inclusion of one short sentence, the paper manages to perpetuate misinformation on grizzly/polar bear hybridization that first appeared in a commentary essay three years ago in Nature  (Kelly et al. 2010)1. The Post et al. 2013 missive contains this astonishing statement (repeated by a Canadian Press news report):

Hybridization between polar bears and grizzly bears may be the result of increasing inland presence of polar bears as a result of a prolonged ice-free season.

Lead author of the paper, Professor of Biology Eric Post, is quoted extensively in the press release issued by his employer (Penn State University, pdf here). In it, Post re-states the above sentence in simpler terms, removing any doubt of its intended interpretation:

“… polar and grizzly bears already have been observed to have hybridized because polar bears now are spending more time on land, where they have contact with grizzlies.

Both statements are patently false. All recent hybridization events documented (2006-2013) occurred because a few male grizzlies traveled over the sea ice into polar bear territory and found themselves a polar bear female to impregnate (see news items here and here, Fig. 1 below). These events did not occur on land during the ice-free season (which is late summer/early fall), but on the sea ice in spring (March-May).

Grizzlies have been documented wandering over the sea ice of the western Arctic since at least 1885 (Doupe et al. 2007; Fig. 2, below) and the presence in this region of hybrid grizzly/polar bear offspring is not an indicator of declining summer sea ice, whether due to global warming or natural causes, or some combination thereof.

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Is there insufficient ice for polar bears to den offshore?

In an earlier post (July 26), I had some critical things to say about an article in the Edmonton Journal (July 17, 2012) by veteran Arctic science writer and photographer Ed Struzik called “Bleak future for polar bears, U of A scientists say“, which was picked up by news outlets across Canada.

The Struzik article publicized a summary academic paper written by polar bear biologists Ian Stirling and Andrew Derocher (a former Ph.D. student of Stirling) that appeared “in press” behind the paywall at the journal Global Change Biology on July 9.

The academic paper is a summary of Stirling and Derocher’s dire predictions on the future fate of polar bears as a result of melting of Arctic sea ice over the next few decades, one of the prophesied catastrophes of anthropogenic global warming. These views mirror to a large degree the chapter on “climate warming” in Ian Stirling’s book on polar bears released in 2011, which I reviewed recently here.

Let’s look at one of the statements made in the Struzik article:

In Alaska, many bears are denning on land because there is insufficient ice for them to give birth offshore.

Update added Aug. 28, 3:35 PM  below the post
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Cooling the polar bear spin

I’ve had quite enough of the obfuscation of facts and model-based extrapolations into the future with regards to polar bears. I’m pretty sure I’m not the only one who is interested in what polar bears are doing now and, as much as can be determined, get some understanding of what the biological, geological and evolutionary history of polar bears and their habitat looks like. Spare us the emotional media hype, icon-peddling and fear-mongering about the future — we’d just like some information about the bears!

Polar bears at the Stanley Park Zoo, Vancouver, taken with my first camera in the early 1970s.

I’ve been looking at the scientific literature produced by polar bear and Arctic seal biologists for some time and I’ve found it contains some rather interesting and potentially important facts that are being left out, glossed over, or misrepresented in statements and publications generated by polar bear advocates of all kinds. It’s past time for these issues to be brought to light and publicized in one easily-accessible, up-datable forum. Hence, PolarBearScience.com — a new blog in which I discuss the science of polar bears while throwing cold water on some of the spin. Continue reading

Ian Stirling’s new polar bear book: a review

This review was originally posted June 30, 2012 at my evolution blog here

It was picked up as a guest post at Hilary Ostrov’s blog “The View from Here” July 1, 2012 under the title Of polar bears, polemics and climate warming


I recently came across a review of Ian Stirling’s latest book Polar Bears: The Natural History of a Threatened Species (2011, Fitzhenry & Whiteside) in the March 2012 issue of the journal Arctic, written by Arctic biologist Steven Ferguson. What is remarkable about Ferguson’s review is not what he says about the book but what he does not: lavish praise for Stirling’s polar bear stories but barely a mention of the book’s dismal predictions for the future. To be fair, all of the photographs in this book are outstanding (some are truly stunning) and the polar bear stories and life history information make for a fascinating read.

However, in reality this is not just a book about polar bears but a polemic discussion about the future of Arctic sea ice. Readers of Ferguson’s review might be surprised to find that there is an entire chapter dedicated to “climate warming” (“the game changer in polar bear conservation” according to Stirling). The climate warming chapter is as eye-catching in its own way as the rest of the book: who could miss the enormous, scary-looking graph predicting summer sea ice declining to zero within the next 90 years (described as a “NSIDC & NASA sea ice decay projection,” taken from Stroeve et al. 2007)? Or the two large photos, from different angles, of a bear that died in 1989 when its winter den collapsed? Oddly, such in-your-face photos and graphics seem not to have impressed Ferguson enough to warrant more than a few words in a list of topics covered (“models of future Arctic change”).

In contrast to Ferguson’s benign and somewhat fawning overview, my impression of the book was quite different.
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