Researchers in the Arctic Basin yesterday spotted a hugely fat pregnant polar bear female on broken ice over water about 2,500 meters deep. Some people seem to find this surprising but it’s what I discussed last week.
Photo above by Tim Kenna from aboard the Coast Guard cutter Healy. Researchers are in the area as part of the “TRACES of Change in the Arctic” program. Another perspective on the bear and the location it was spotted on 24 August 2015 below, as well as some background on Arctic Basin bears.
Now, not so much. Here is a 16- year old CBC TV special on Churchill polar bears – listen to Ian Stirling and reporter Eve Savory use the early breakup of sea ice on Hudson Bay in 1999 to hype the alarm about Western Hudson Bay polar bears. Watch Stirling in action darting and measuring bears and bemoaning the good old days of the 1980s, claiming the “bears are sending a signal from the ecosystem.”
Watch this archived copy of “The Shrinking Bears of Hudson Bay” and compare his claims to what has actually happened in the 16 years since then. It runs just over 15 minutes.
“Just as the ice is shrinking in Hudson Bay, so are its polar bears. Climate change has shortened the season for winter ice, a crucial period for the bears to feast on seals and build up their fat reserves. And so, over the 18 years that wildlife biologist Ian Stirling has been studying them, the polar bears have become skinnier and their offspring fewer. In this 1999 report for CBC-TV’s The National, Stirling says once their habitat is gone, there’s nowhere else the Hudson Bay polar bears can go.” [my bold – see notes below]
• Program: The National [Canadian Broadcasting Company, CBC]
• Broadcast Date: Sept. 23, 1999
• Duration: 16:39
Stirling has continue to make these claims since 1999, yet no updated evidence has been provided. There is no plausible evidence that the decline of polar bear numbers in Western Hudson Bay was due to sea ice changes caused by human-caused global warming (Crockford 2015) or that continued declines in condition of bears or litter size have occurred. Note that the latest survey of Western Hudson Bay polar bears found no trend in either breakup or freeze-up dates since 2001 (Lunn et al. 2013) and that the population is now stable.
Ice coverage charts and breakup dates graph below, for context.
UPDATE ADDED – see below
Posted in Life History, Sea ice habitat
Tagged body condition, breakup, CBC, Churchill, climate change, freeze-up, global warming, Hudson Bay, litter sizes, polar bear, population estimate, sea ice, Shrinking Bears, Stirling, western hudson bay