Despite the public outcry last week over future polar bear survival, the polar-bears-are-doomed crowd can’t hide the fact that this year, spring sea ice habitat for polar bears worldwide has been excellent.
This year on 19 July, for example, Hudson Bay had greater than 150,000 square km more sea ice than there was in 2009 on that date (526.2 vs. 368.5 mkm2)(1992 was a particularly cold year and most bears left the ice as late in 2009 as they did in 1992).1 Conditions have also been excellent for pregnant females around Svalbard – Norwegian polar bear researchers recently reported a good crop of cubs this spring.
Worldwide, there was exactly the same amount of Arctic sea ice present on 18 July 2015 as there was back in 2006 (Day 199) – 8.4 mkm2. By 19 July (day 200), 2015 had more ice than 2006 (8.4 mkm2 vs. 8.3).
All this means that recent summer ice melt has not impinged on the spring feeding period that is so critically important for polar bears. So much ice left in early summer means there was lots of sea ice in the spring (April-June), even in the Southern Beaufort Sea.
The only region with sea ice coverage well below the last five years is the Chukchi Sea (see plots below, click to enlarge). So why aren’t we hearing the-sky-is-falling stories about Chukchi bears? Because biologist have already demonstrated that polar bears in the Chukchi do very well even with no summer sea ice.
Posted in Life History, Sea ice habitat
Tagged Chukchi Sea, Derocher, habitat, Hudson Bay, melt ponds, polar bear, polar bear science, sea ice, Southern Beaufort, spring ice conditions, summer sea ice, Svalbard, thick spring ice, tracking polar bears, walking hibernation
A polar bear paper just out in Science concludes the experts were wrong, polar bears are not “walking hibernators” – in summer, they slow down and live off their accumulated fat just like other mammals. Take home message: experts are not infallible and spring fat is critical for polar bear survival over the summer.
This paper presents no compelling evidence that Southern Beaufort polar bears, or those in any other region, lack the ability to survive predicted summer sea ice declines in future decades – although they claim it does. See what you think.
Posted in Life History, Sea ice habitat
Tagged Alaska, Amstrup, Arctic Fallacy, Beaufort Sea, Ben-David, fast, fat, hibernation, polar bear science, polar bears, Regehr, sea ice, Southern Beaufort, summer, temperatures, walking hibernator, Whiteman
If so, they’re not saying. This year, with higher-than-average sea ice, we’ve heard much less than usual about the location of tagged Hudson Bay polar bears. Odd, isn’t it?
By this time last year, Polar Bears International rep Alysa McCall had published two reports on the location WHB polar bears tagged by the University of Alberta research team led by Andrew Derocher (Fig. 1 below).
Figure 1. Sea ice coverage and locations of female polar bears with tracking collars for 30 June 2014 and 8 July 2014 (black, Western Hudson Bay bears; blue, Southern Hudson Bay bears), courtesy Alysa McCall, Polar Bears International. Click to enlarge.
This year, there’s been nothing: not a single PBI mention of WHB breakup. Derocher tweeted a track map on 6 July (2/9 bears ashore), with no updates since, but PBI’s “Bear Tracker” has not been updated since 2 July. Compare this year’s ice cover on Hudson Bay (and elsewhere in Canada) to last year on this date (14 July): quite a difference.
There is still a lot of sea ice in Hudson Bay, Foxe Basin, Davis Strait and Baffin Bay this week – more than average for this date – with slightly less than average in the Beaufort Sea. Past behaviour of Western and Southern Hudson Bay polar bears suggests the mean date that bears come ashore for the summer this year will be later than average due to the plentiful ice available, regardless of when polar bear biologists decide that “breakup” has occurred.
Hudson Bay, with almost 50% of the bay still covered in ice, has the third highest coverage this week since 1992 (after 2009 and 2004); Davis Strait has the highest coverage since 1992; and Foxe Basin and Baffin Bay have the highest coverage since 1998. For this week, the Beaufort Sea has the second highest coverage since 2006 (after 2013), and more ice than was present in 1971, 1982, 1987, 1988 and 1998 – among others.
Published data shows that most polar bears of Western Hudson Bay traditionally come ashore in July, but this year it might be late July or even August. Have a look at the charts below.
Continue reading →
Posted in Sea ice habitat
Tagged baffin bay, Beaufort Sea, breakup, Davis Strait, Derocher, females, Foxe Basin, Hudson Bay, ice coverage, leaving the ice, onshore, polar bear, polar bear science, sea ice, summer
Between-the-lines message of the recently released (and hyped to death) Conservation Management Plan for polar bears by the US Fish & Wildlife Service is that the bears really have nothing to worry about except human-caused global warming but it will cost tens of millions of dollars over the next five years to study and manage them.
So filled with double-speak, misinformation, and obfuscation [including the newly-invented term, “quasi-extinction floor”] that it’s no wonder some news outlets got it wrong (nowhere in this document does it say that “polar bears might go extinct within ten years“). The document does, however, lay out the FWS budget for polar bears over the next five years – and it’s a real eye-opener.
Posted in Advocacy, Population, Sea ice habitat
Tagged 5 year plan, Alaska, budget, Chukchi Sea, climate change, costs, global warming, greenhouse gases, habitat, management, polar bear, polar bear science, population estimate, science, sea ice, Southern Beaufort, US Fish and Wildlife Service, USGS
I’ve got an imitator! It appears that a recently created website promoting polar bear biologist Andrew Derocher’s lab at the University of Alberta just happens to have the same title as my blog: Polar Bear Science.
Oscar Wilde said:
“Imitation is the sincerest form of flattery that mediocrity can pay to greatness.”
Gosh, I’m seriously chuffed.
From the look of it, Derocher and his students would like to ride on the coattails of my online success and garner some Google-search views for themselves – check my blog stats, lower right: I’m coming up on half a million views in just under three years (since 26 July 2012).
Sadly for them, it does not appear to be working.
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