Monthly Archives: September 2012

Critical evidence on polar bears in W. Hudson Bay is unpublished

In my last post, Western Hudson Bay polar bears are not like the others – Part 1 I stopped at the point where the following question arose: “The documented decline in cub survival and condition of females documented above occurred between 1985 and 1992 – what about now?

I promised to address that question in a separate post because it revealed some interesting issues that deserve star billing.

What I found might surprise you: apparently, virtually all of the data supporting a decline in the western Hudson Bay polar bear population since 1985 has been collected but has not been published. This revelation came from none other than the 2012 summary by Ian Stirling and Andrew Derocher that I’ve mentioned before here.

[updated Sept. 28, 2012 - reference added, see below]

continue reading

Western Hudson Bay polar bears are not like the others – Part 1

A review paper, purporting to list the “effects of climate warming on polar bears” (Stirling and Derocher 2012:2697), has this to say about the state of research in western Hudson Bay:

“The most comprehensive long-term research on polar bear demography, body condition, subpopulation size, abundance, and reproductive success has been conducted on the Western Hudson Bay subpopulation.”

This means that compared to all of the 19 subpopulations of polar bears (see fig. 1), the very best information we have is for Western Hudson Bay (WHB) bears (fig. 2).

But are western Hudson Bay polar bears biologically typical of all polar bears? In this post, I’ll begin to examine that question.

Continue reading

The slaughter of polar bears that rarely gets mentioned (ca. 1890-1930)

Chock this post up as another example of mind-blowing information you sometimes find while looking for something else.

In their dendrochronology paper on trees associated with polar bear dens in western Hudson Bay, Scott and Stirling (2002:157) reference an MA thesis in Geography by James Honderich (1991), in regards to a discussion of denning frequency during the period 1850-1899, “when polar bear hides were more or less traded consistently.”

It turns out the James Honderich’s thesis is actually a summary of polar bear harvests in Canada from about 4,000 years ago to 1935. The number of polar bears taken by Arctic explorers (1594 to mid-1900s), Hudson’s Bay Company fur traders (from 1670 to 1935) and Arctic whalers (1820s-1935) were calculated from a variety of historical sources. This post is a summary of the results for the period 1800-1935. It is likely you have never seen this astonishing information before and the implications for polar bear biology are substantial. Continue reading

Another polar bear advocate writes a book: Derocher and Lynch 2012

Polar Bears: A Complete Guide to their Biology and Behavior (2012) Text by Andrew E. Derocher, Photographs by Wayne Lynch, in association with Polar Bears International. Johns Hopkins University Press 264 pp. 153 color photos, 4 maps. 978-1-4214-0305-2    $39.95 hardcover

Here is the promotional description of this book:

“Derocher and Lynch have spent decades following polar bears, and this book offers the most comprehensive and readable review of their biology, ecology, behavior, and conservation.” From the JHUPress catalogue

This statement suggested to me that I would find Andrew Derocher’s new book upbeat and primarily concerned with explaining the biology, behavior and life history of polar bears, as the title suggests. I’d buy a book like that, I thought.

I was also eager to see how Derocher’s effort compared with Ian Stirling’s book that came out last year (2011), which I reviewed in July. The title of Stirling’s book – Polar Bears: The Natural History of a Threatened Species – did at least hint at the advocacy found within.

Would Derocher’s book be substantially different, despite his strident advocacy on display just last month in the press “Bleak future for polar bears, U of A scientists say” and in his most recent co-authored scientific paper (Stirling and Derocher 2012, now in print), that I discussed briefly in my first post? Continue reading

First month for Polar Bear Science – Aug, 2012

First posts went up July 26.

Total views @ Aug. 31 – 2454

Total views:
July 2012 -    567
Aug. 2012 – 1887

Over the last three weeks, views have been >600/week, an average of 91/day.

Largest spikes in readership were generated not by new posts (surprise!) but by media coverage:
1) television, newspaper and radio interviews associated with my lecture at the University of Toronto Aug. 14, “Polar Bears: Outstanding Survivors of Climate Change”;
2) one of my posts was featured at Climate Depote on Aug. 31.

I am happy to report that so far, all of the comments I have received via the “comments/tips” page have been positive.

No one has yet asked for references. So, just to be clear, I am happy to send pdfs of any references I cite in my posts (if I have them – not always available, e.g. book chapters). Simply use the “Requests” contact page. Just because you don’t have access to a university library should not mean you can’t get to the science. Don’t take my word for anything – if you have doubts about what the research papers say, go to the source. Just ask!

I felt one comment by a reader was worth posting, so with their permission, I added it to the post as an update. Another commenter sent me photos, which I happily added, noted as an update.

I’ve got some interesting posts lined up, including another book review – stay tuned.

Enjoy the rest of your long weeekend.

PS. Huge thanks to Tom Nelson for highlighting my posts and Hilary Ostrov for technical advice to this novice blogger.