Polar bear biologist Andrew Derocher published a tracking map of his collared polar bear females that shows one bear (out of 11) still on the rapidly diminishing ice north of Churchill in Western Hudson Bay – and where there is a collared female, there is almost certainly other bears doing the exact same thing:
Without evidence to support such a claim, Derocher (below) assumes this collared female is probably hunting seals. In fact, last year he admitted that most bears on Hudson Bay from at least July onward are unlikely to be successfully hunting seals:
Contrary to all expert expectations, five female polar bears (45%) out of eleven that had tracking collars attached last year were still out on the sea ice that’s lingering along the western shore of Hudson Bay as of 7 August. And if five collared bears are out there, then there are almost certainly many more without collars doing the same thing. This pattern of bears staying out on the ice long after the so-called ‘critical threshold’ of 50% concentration has passed has been going on since at least 2015 and many bears on tracking maps in July and August appear to be on ice that doesn’t exist.
There are two explanations for this pattern and both are likely true: 1) much more ice actually exists on Hudson Bay than satellites can detect and 2) polar bear experts are wrong that Western Hudson Bay polar bears head to land soon after sea ice concentration drops below 50%. Models that predict a catastrophic future for Western Hudson Bay polar bears (Castro de la Guardia et al. 2013; Molnar et al. 2020) assume that ice coverage of less than 50% in summer greatly reduces polar bear survival. However, if polar bears do not always head to land when sea ice drops below 50% then the models cannot possibly describe their future accurately. In other words, depending on the discredited ‘worst case’ RCP8.5 climate scenario for the most recent polar bear survival model that extrapolates from Western Hudson Bay bear data to many other subpopulations, as I discussed previously, may not be its only fault.
Posted in Conservation Status, Life History, Sea ice habitat
Tagged assumptions, behavioural plasticity, breakup, contradictions, extinction, Hudson Bay, melt ponds, polar bear, predictions, RCP8.5, sea ice, western hudson bay
In something resembling a new pattern for Western Hudson Bay polar bears, most of the animals are still out on the ice in late July this year, just like they were in the 1980s. The same thing happened last year but was brushed off as a happy anomaly. However, after last fall’s 1980s-like early freeze-up, this makes the sixth year in a row of good to very good sea ice conditions for Western Hudson Bay polar bears. No wonder polar bear experts haven’t published these data: good sea ice conditions along with polar bears coming ashore fat and healthy are not just inconvenient – they threaten to destroy the extinction panic narrative that depends on Western Hudson Bay bears showing evidence of harm from reduced sea ice.
Fat mother and cub onshore at Wakusp National Park, Western Hudson Bay 18 July 2020, one of the first of the season.
Posted in Advocacy, Life History, Sea ice habitat
Tagged breakup, catastrophe, extinction, good years, Hudson Bay, models, polar bears, prediction, proxy, sea ice, trends, western hudson bay
Here is a quick compare and contrast of sea ice habitat for polar bears in Canada and the Southern Beaufort region of eastern Alaska near the end of June, 2012-2020.
Similarities between Hudson Bay ice/open water in the sea ice charts below are striking. Ice cover at the end of June shown in these charts since 2012 reinforces the fact, documented in the peer-reviewed literature, that there has been no continued declining trend in dates of sea ice breakup for Western and Southern Hudson Bay since 1998 at least (Castro de la Guardia et al. 2017; Lunn et al. 2016). WH bears are still on the ice.
As a consequence, recent declarations of impending doom for Hudson Bay polar bears, based on claims of reduced population size and health of these subpopulations – which in any case are statistically insignificant for WH and SH (Obbard et al. 2018; Dyck et al. 2017) – must be due to some other cause (Crockford 2020).
In all areas, winds rather than melt due to increased temperatures drive much of the expansion of open water at this time of year.
Posted in Conservation Status, Population, Sea ice habitat
Tagged Alaska, Beaufort, breakup, Canada, cause and effect, Hudson Bay, melt, polar bear, population decline, sea ice, western hudson bay
No early breakup of Hudson Bay sea ice again this year: there is still extensive thick first year ice over most of Hudson Bay and all female polar bears fitted with tracking collars in Western Hudson Bay are still on the ice:
W Hudson Bay polar bears still out on the ice that’s packed together by winds. AE Derocher, 12 June 2020
Breakup of Hudson Bay sea ice as it relates to polar bear movement to land has been about the same since 1999 (about 2 weeks earlier than in the 1980s) and this year is shaping up to be no different: there is still no declining trend in date of sea ice breakup in Western Hudson Bay despite repeated predictions of imminent doom. An especially ‘early’ breakup year would have bears ashore before 15 June. Last year (2019) the first WH bear onshore was caught on film 5 July and problem bears were not recorded onshore in Churchill until the 2nd week of July.
Posted in Conservation Status, Life History, Sea ice habitat
Tagged breakup dates, declining population, early breakup, Hudson Bay, polar bear, sea ice, threatened, trends, western hudson bay
Here are ice conditions at the end of May, which signals the near-end of the critical spring feeding period for polar bears. This is because young-of-the-year seals take to the water to feed themselves, leaving only predator-savvy adults and subadults on the ice from some time in June onward (depending on the region).
Spring is the critical feeding period for polar bears (Crockford 2019, 2020; Lippold et al. 2020; Obbard et al. 2016):
“Unexpectedly, body condition of female polar bears from the Barents Sea has increased after 2005, although sea ice has retreated by ∼50% since the late 1990s in the area, and the length of the ice-free season has increased by over 20 weeks between 1979 and 2013. These changes are also accompanied by winter sea ice retreat that is especially pronounced in the Barents Sea compared to other Arctic areas. Despite the declining sea ice in the Barents Sea, polar bears are likely not lacking food as long as sea ice is present during their peak feeding period. Polar bears feed extensively from April to June when ringed seals have pups and are particularly vulnerable to predation, whereas the predation rate during the rest of the year is likely low.“ [Lippold et al. 2019:988]
Posted in Life History, Sea ice habitat
Tagged Beaufort, Chukchi, feeding, Hudson Bay, open water, polar bear, polynya, sea ice, seals, spring, summer
The chart below shows what sea ice thickness over Hudson Bay was like at the first week of May in a so-called a ‘good year’ (2019) – when polar bears came off the ice in excellent condition late in the summer and left early in the fall (‘thick first year ice’ is dark green and indicates ice greater than 1.2m thick):
Hudson Bay ice conditions this year appear to be shaping up to be as good or better than last year for polar bears yet specialist researchers and their cheerleaders have still been claiming that bears in this region – Western and Southern Hudson Bay – are doomed because of poor ice conditions. It’s no wonder they still haven’t published the data they’ve been collecting on polar bear body condition and cub survival over the last 15 years or so (Crockford 2020). With most field work cancelled for this year, what’s their excuse for not getting that done?
Arctic sea ice at the middle of winter (January-March) is a measure of what’s to come because winter ice is the set-up for early spring, the time when polar bears do most of their feeding on young seals.
[Mid-winter photos of polar bears are hard to come by, partly because the Arctic is still dark for most hours of the day, it’s still bitterly cold, and scientists don’t venture out to do work on polar bears until the end of March at the earliest]
At 12 February this year, the ice was similar in overall extent to 2013 but higher than 2006.
Polar bears leaping on the backs of belugas off Seal River, in western Hudson Bay, is being falsely promoted by the BBC’s new “Seven Worlds: One Planet” TV special as an unprecedented effect of climate change.
More specifically, the Daily Mail (30 November 2019) this morning quoted the documentary, narrated by Sir David Attenborough, as saying:
‘This extraordinary behaviour has only been recorded here, in this remote corner of North America, and only in the last few years.’
Poppycock. More climate change hyperbole from Attenborough’s seemingly never-ending litany of nonsense that’s easily refuted. There is scientific literature documenting such behaviour in Canada’s far north in the 1980s, which I included in the blog post I wrote about this phenomenon a few months ago (after National Geographic published a similar scare-story), which I have reposted below.
And from the sounds of it, there was no mention in the BBC special that freeze-up along western Hudson Bay was early again this year: for the third year in a row. So if the footage was filmed any time since 2017, the claim of accelerating sea ice loss in this region and bears on land for longer than ever is pure fantasy. PS. Fat bears are not ‘starving’.
Posted in Advocacy, Conservation Status, Life History, Sea ice habitat
Tagged Attenborough, BBC, beluga, climate change, Hudson Bay, hunting, polar bear, sea ice, Seven Worlds One Planet, shore, starving
This is the third year in a row that freeze-up of Western Hudson Bay (WH) ice has come earlier than the average of 16 November documented in the 1980s. Reports by folks on the ground near Churchill confirm polar bears are starting to move onto the sea ice that’s developing along the shore after almost 5 months on land. After five good sea ice seasons in a row for WH polar bears, this repeat of an early freeze-up means a sixth good ice season is now possible for 2019-2020.
Sadly for the tourists, however, it means the polar bear viewing season in Churchill will be ending early this year, just like it did last year and the year before.
Polar bear family on the ice off Churchill Manitoba (taken from a helicopter), courtesy Explore.org
When mothers with cubs are out on the ice (see photo above), it’s pretty certain the mass movement from land to sea ice is well underway because these family units are usually the last to leave.
UPDATE 19 November 2019: Polar Bear Alert report for 11-17 Nov (week 20) confirms that freeze-up is underway, bears are heading out on the ice and problem bears held in the ‘jail’ were released 13 November. See below.