In a just-released Discovery News piece, Kieran Mulvaney (4 November 2015, “In the polar bear capital, an uncertain future”) repeated three misleading statements about Western Hudson Bay polar bears that keep making the rounds, despite the fact they have been laid to rest by the latest scientific reports on (Lunn et al. 2013, 2014; Stapleton et al. 2014). I reviewed these just a few weeks ago.
Western Hudson Bay bear, Wakusp National Park, August 2011.
1) “Climate change is causing the bay’s ice to melt earlier and freeze later, causing bears to spend longer a shore.”
Not true. Lunn and colleagues stated explicitly that there has been no trend in either break up or freeze-up of WHB sea ice since 2001. Although there has been large variability in dates, that lack of trend that has continued to this year.
2 & 3) “As a consequence, Churchill’s polar bears are decreasing in number (from approximately 1,350 three decades ago to roughly 900-1,000 now) and in physical condition.”
This deliberately misleading statement avoids the fact that the latest surveys found roughly the same number of bears in 2011 as in 2004 (the estimate used by the IUCN Polar Bear Specialist Group for WHB is 1030) when different counting methods were taken into account. The ~900 bear estimate came from the mark-recapture survey, which left out a portion of the range that the aerial survey covered, hence the official estimate of 1030.
In addition, there has been no scientific assessment of body condition or cub survival since before the last population estimate in 2004 – polar bear “experts” keep telling journalists there are declines but have yet to produce any data to support those claims. The latest surveys did not collect data on body condition or cub survival.
Mulvaney’s misinformation is almost certainly the result of spending time in Churchill with activist Polar Bears International spokesperson Steve Amstrup and activist climate scientist Katherine Hayhoe doing webcasts (e.g. “Challenges of communicating climate change”).
Mulvaney is clearly not a journalist or a science writer: if he was, he would do some research of his own and stop believing as gospel every word that activist scientists feed him. They are using him as a mouth-piece and sadly, Discovery News is buying it all and presenting it as science.
[Hayhoe, by the way, blocked me on twitter earlier this morning for making one observational comment, my first-ever to her account, in response to a conversation about polar bear population numbers. This is what I said that Hayhoe does not want her followers to know:
“Stop wanton slaughter, #’s go up, works for all species. S Beaufort #polarbear #s dipped due to thick spring #seaice”
Both statements are true and supported by scientific literature. But Hayhoe is all about “climate communication” which appears not to allow science to intrude.]
References
Lunn, N.J., Regehr, E.V., Servanty, S., Converse, S., Richardson, E. and Stirling, I. 2013. Demography and population assessment of polar bears in Western Hudson Bay, Canada. Environment Canada Research Report. 26 November 2013. PDF HERE
Lunn, N.J., Servanty, S., Regehr, E.V., Converse, S.J., Richardson, E. and Stirling, I. 2014. Demography and population assessment of polar bears in Western Hudson Bay, Canada. Environment Canada Research Report. July 2014. PDF HERE [This appears to be the version submitted for publication]
Stapleton S., Atkinson, S., Hedman, D., and Garshelis, D. 2014. Revisiting Western Hudson Bay: using aerial surveys to update polar bear abundance in a sentinel population. Biological Conservation 170:38-47. http://www.sciencedirect.com/science/article/pii/S0006320713004618#
The significant information contained in this paper is breakup and freeze-up dates and length of the ice-free period data for 2010-2015, which has been unavailable until now. More excerpts and comments below, including Figure 3 with its caption. Continue reading
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