Polar bears and melting ice: three facts that shouldn’t surprise you

If I was invited by USA TODAY to discuss how climate change is affecting polar bears now – summed up in three talking points – this is what I’d say. I’d use some meaningful images rather than cute pictures of cuddly bear cubs and I’d provide links to my work with references and details to back up my answers.

Compare my responses to those supplied by Steve Amstrup in his capacity as spokesperson for Polar Bears International (“Save our sea ice!”) to Jolie Lee at USA TODAY last week, who’s word is expected to be taken as gospel.

AK PB N Shore-USFWS Barrow_labeled

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W Hudson Bay mark-recapture studies of polar bears were invalid, says peer-reviewed study

“Our results suggest that mark–recapture estimates may have been negatively biased due to limited spatial sampling. We observed large numbers of bears summering in southeastern WH, an area not regularly sampled by mark–recapture.” Stapleton et al. 2014.

Polar bear at Wapusk National Park (just south of Churchill) in August 2011. Courtesy Parks Canada.

Polar bear at Wapusk National Park in August 2011. Courtesy Parks Canada.

We’ve seen the results of this 2011 study before, in government report format. But now it’s been revamped, peer-reviewed and published in a respected scientific journal – it actually came out in February, without fanfare, but I’ve only just come across it.

Some excerpts below, with conclusions that should raise some eyebrows.

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Counting bears from space can be just as accurate as by helicopter, claims new study

Satellites images might be able to replace aerial counts of polar bears in some places — if there are no clouds. But it seldom distinguishes cubs and can’t tell males from females, found a 2012 study of Foxe Basin bears that’s just been published.

Foxe Basin polar_bears_rowley_island_Stapleton 2012 press photo labeled sm

Note: This is my 200th post since July 26, 2012!

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Breakup date average for W. Hudson Bay is July 1 – this year, it’s late again

In the last few days, ice coverage on Western Hudson Bay finally dropped below the 30% level that now defines ‘breakup’ for polar bears: a few bears near Churchill started to come ashore late last week but most will stay on the ice until the end of July. That means breakup this year was unofficially July 8th, a week later than average (July 1) for the third year in a row.
Sea ice extent Canada 2014 July 7 CIS

Don’t’ tell that to the folks at Polar Bears International, though, because they’re busy telling people that the ice-free season for Western Hudson Bay bears is now longer than it was before the 1990s. What they mean is that the overall trend is toward early breakup dates.

But what they don’t admit is that over the last 44 years, breakup was a full two weeks earlier than average for Western Hudson Bay only six times and only three of those early breakups occurred within the last 13 years. See the calculations below and see what you think.

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Are Polar Bears Really Endangered?

Christina Wu at the Urban Times (July 3, 2014) recently asked this question. She came up with a surprisingly balanced argument but some predictable responses from IUCN Polar Bear Specialist Group (PBSG) biologists. As a consequence, she overlooked some critical facts that make a big difference to the answer.

Figure 1. Are polar bears really endangered? The US Fish and Wildlife Service thinks so, but only because Steven Amstrup, based on a computer model projecting sea ice out to 2050, said so (Amstrup et al. 2007). This information has been used by the Center for Biological Diversity and other NGOs, like WWF and Polar Bears International (where Amstrup is now employed), to solicit donations.

Figure 1. Predictions of polar bear population declines by 2050 are being used by the Center for Biological Diversity, WWF and Polar Bears International to solicit donations.

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Tracking polar bears in the Beaufort Sea: June 2014 map

Here is the June 2014 follow-up to my post on the July 2013 track map for female polar bears being followed by satellite in the Beaufort Sea by the US Geological Survey (USGS) – “Ten out of ten polar bears being tracked this summer in the Beaufort Sea are on the ice.”

See that post for methods and other background on this topic, and some track maps from 2012 (also available at the USGS website here).

The USGS track map for June 2004 is copied below (Fig. 1).

Compare this to May’s map (Fig. 2) – the 20 bears from last month are down to 14, and all seven of the bears outfitted with glue-on satellite transmitters in April [either males or subadult animals] have either moved out of the area or their tags have fallen off or stopped transmitting. This means that all of the bears shown on the June map below are females with satellite radio collars.
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Polar Bear Specialist Group just had another secret meeting

Well, well, well — it looks the Polar Bear Specialist Group (PBSG) just had itself another secret meeting with some extra special guests.

pbsg logoPolar bear scientists and PBSG-approved activists got together a few weeks ago (June 9-13), with no notice beforehand, to continue discussions how (sic) to solve issues of future capacity.”

This was their “second intersessional members-only meeting in a row” (the first one was in October 2012), but they still haven’t had their regular, now long-overdue, “working meeting.” [they had the last one in 2009].

I came upon a notice about this meeting on the PBSG website, which apparently went up June 26, while looking for something else. There has been nothing about it in the media that I’ve seen.

And guess who were “invited specialists” at this meeting of “members-only,” called “to discuss internal matters crucial for the future functioning and capacity of the group”?

Three “climate scientists“!

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