A few weeks into the Arctic summer (July-September), sea ice in the Beaufort and Chukchi Seas is dominated by thick, multi-year ice.
At this time of year, multi-year ice is an important refuge habitat for many polar bears when seasonal ice melts out. However, it provides few opportunities for hunting seals. In fact, it is nearly as devoid of food as is the shore during the melt season. Consequently, most polar bears eat little over the summer whether they are on land or on sea ice due to the scarcity of seals.
At this time of year, sea ice extent numbers are meaningless for polar bears. The extreme low September minimum of 2012 – when masses of polar bears didn’t die – showed rational people that this is true. Even the low 2007 summer extent, which hit earlier in the season than 2012, had little to no negative impact.
In late summer, bears outside the Canadian Archipelago either retreat to shore or stay on the sea ice as it retreats north into the Arctic Basin (see image below, click to enlarge). Most bears in the Archipelago have ice year round, so life doesn’t change much. This means that it does not matter to polar bears how much area the Arctic Basin ice covers in September – for their needs, 1.0 mkm2 would be plenty.
Still, Southern Hudson Bay polar bears had extended hunting opportunities in July this year (whether or not they hunted successfully) and for this date, Hudson Bay had more ice remaining than any year on record. Yes, more than even 1992 but only by a few percent. See charts and maps below.
Posted in Life History, Sea ice habitat
Tagged Arctic basin, fasting, habitat, Hudson Bay, MASIE, minimum, passive microwave, polar bear, sea ice, September, starving, summer, thin ice
Some polar bears may already be living mostly off the fat put on over the spring but others may catch a seal or two on the sea ice before the summer fast begins – since the ice hasn’t left the coast in most regions quite yet. Polar bears eat little in summer, whether they spend their time on land or on the sea ice.
Sea ice is still high over Hudson Bay – for this time of year, it hasn’t had this much polar bear habitat since 2009. Davis Strait and Foxe Basin are also above average – Davis Strait hasn’t had this much ice since 1992 (the Mt. Pinatubo cold year). Polar bear subpopulation refresher map below.
Posted in Sea ice habitat
Tagged Alaska, breakup, condition, Davis Strait, fasting, fat, habitat, Hudson Bay, polar bear, science, sea ice, Southern Beaufort, summer, Svalbard
In what looks like a follow-up to last week’s CBC documentary, The Politics of Polar Bears, the London (UK) based DailyMail published interviews with polar bear biologists Mitch Taylor and Andrew Derocher (September 9, 2014).
The CBC film did have a “one scientist vs. another” flavor about it and this article definitely echoes that approach. My comments below on Derocher’s insinuations and questions about starving bears and global warming.
Posted in Advocacy, Conservation Status, Sea ice habitat
Tagged caribou, conservation, DailyMail, Derocher, fasting, goose eggs, Gormezano, ice-free season, Mitch Taylor, polar bears, Rockwell, sea ice, sea ice decline, starving, survival, terrestrial foods, weight loss, western hudson bay
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.
Posted in Advocacy, Cannibalism, Polar bear attacks
Tagged Amstrup, Arviat, cannibalism, climate change, disappearing population, fasting, global warming, hibernation, human-bear conflicts, melting ice, polar bear, polar bear attacks, starving bears, Stirling
I guess Suzanne Goldenberg, writing for The Guardian, just couldn’t help herself with this latest story (November 4): “Polar bear attacks: scientists warn of fresh dangers in warming Arctic. Two people injured in latest attack as hungry bears deprived of access to sea ice increasingly look for food on land.”
Reporting on the attack is one thing — several papers covered this over the weekend (see Featured Quote #46, posted yesterday, for links to two of them). However, Goldenberg shamelessly makes this about global warming, aided and abetted by Polar Bears International (PBI) representative Steven Amstrup, a claim that doesn’t hold up to even minor scrutiny.
Posted in Cannibalism, Polar bear attacks, Sea ice habitat
Tagged Amstrup, bear-human conflicts, breakup, Churchill, fasting, freeze-up, global warming, Goldenberg, Guardian, hungry polar bears, National Post, polar bear, Polar Bears International, starving polar bears, western hudson bay