Tag Archives: ice-free season

Western & Southern Hudson Bay polar bears experience earliest freeze-up in decades

This is shaping up to be one of the shortest ice-free seasons in at least 20 years for both Western and Southern Hudson Bay polar bears.

Hudson Bay sea ice at 2 November 2020. NSIDC Masie chart.

Last week, sea ice started forming along the shore of Hudson Bay, from the north end all the way south into James Bay. So far, the shorefast ice that’s forming is only a narrow strip along the coast but is thickening and becoming broader each day, which means that unless something changes dramatically, the bears should all be on the ice at the end of the week, an exodus from shore that hasn’t happened this early in WH since 1993 (the earliest since 1979).

The last WH tagged polar bear didn’t leave the ice this year until 21 August, which means if it’s on the ice by the end of this week it will have spent only 11 weeks onshore – less than 3 months. Even the first bears that came ashore in mid-July will have only spent about 16 weeks on land – at least a month less than they did a decade ago (Stirling and Derocher 2012). Four months spent ashore was the historical average for Western Hudson Bay bears in the 1970s and 1980s (Stirling et al. 1977, 1999). This year, most polar bears will have spent only about 13-14 weeks on land because they did not come ashore until early August.

UPDATE 8 November 2020: Report from Churchill area polar bear guide Kelsey Eliasson, via Facebook Saturday 7 November: “Most bears have left on the ice – including peanut – but still some stragglers” [Peanut’ is a well-known female who has two cubs this year]. See below for sea ice chart for 8 November shows broadening band of grey ice clearly thick enough to support the weight of adult bears (and the same thing is happening in Southern Hudson Bay):

Hudson Bay North daily stage of development 2020 Nov 8_all grey ice

Continue reading

New model of predicted polar bear extinction is not scientifically plausible

Apparently, a prediction that polar bears could be nearly extinct by 2100 (which was first suggested back in 2007) is news today because there is a new model. As for all previous models, this prediction of future polar bear devastation depends on using the so-called ‘business as usual’ RCP8.5 climate scenario, which has been roundly criticized in recent years as totally implausible, which even the BBC has mentioned. This new model, published today as a pay-walled paper in Nature Climate Change, also did something I warned against in my last post: it uses polar bear data collected up to 2009 only from Western Hudson Bay – which is an outlier in many respects – to predict the response of bears worldwide. The lead author, Peter Molnar, is a former student of vocal polar bear catastrophist Andrew Derocher – who himself learned his trade from the king of polar bear calamity forecasts, Ian Stirling. Steven Amstrup, another co-author of this paper, provided the ‘expert opinion’ for the failed USGS polar bear extinction model featured in my book, The Polar Bear Catastrophe That Never Happened.

James Bay female and cub_Ontaro Govt

Well, these authors and their supporters got the headlines they crave, including coverage by outlets like the BBC and New York Times (see below) but I have to say that the combination of using out-of-date Western Hudson Bay information on when polar bears come ashore in summer and leave for the ice in fall (only to 2009) to make vague projections (‘possible’, ‘likely’, ‘very likely’) about all other subpopulations in addition to depending on the most extreme and now discredited RCP8.5 climate scenario (Hausfather and Peters 2020) for this newest polar bear survival model is all that’s needed to dismiss it as exaggerated-fear-mongering-by-proxy. Why would anyone believe that the output of this new model describes a plausible future for polar bears?

New York Times headline _climate change pushing pbs to extinction_20 July 2020
Continue reading

New Paper: Body condition of Barents Sea polar bears increased since 2004 despite sea ice loss

A recent paper that attempted to correlate pollution levels and body condition in Barents Sea polar bears reports it found body condition of female bears had increased between 2004 and 2017 despite a pronounced decline in summer and winter sea ice extent.

Svalbard polar bear Jon Aars_Norsk Polarinstitutt

“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” [Lippold et al. 2019:988]

Continue reading

Fat healthy polar bear update: hundreds of not-starving bears attracted to dead whale

Are the hundreds of polar bears spending the summer on Wrangel Island in the Chukchi Sea starving and desperate for any scrap of food? Hardly! Photos taken by Russian tourists on a cruise ship (19 September 2017) show a huge number of already-fat, healthy bears converging on a dead bowhead whale washed up on a beach. Most of these bears would have been without food since at least early August, when the last sea ice disappeared around the island, and will return to the ice by November.

Wrangel Island bears on whale_29 Sept 2017 SUN

This is what The Sun reported (29 September), based on a Siberian Times story (my bold):

The extraordinary sight was witnessed by tourists on an Arctic cruise aboard the Finnish-built MV Akademik Shokalskiy.

A source at Wrangel Island Nature Reserve said: “There were at least 230 polar bears, including single males, single females, mothers with cubs and even two mothers with four cubs each.”

Experts called the sight of so many polar bears together “unique”.

The huge number could in fact amount to as much one per cent of the entire world’s population of the creatures.

Tourists initially thought the bears were a flock of sheep after viewing them from a distance, The Siberian Times reports.

But as the boat drew closer, the lucky holidaymakers realised what they were witnessing.

Fat cubs of the year are seen in the photo below, from the Siberian Times story:

Wrangel Island bears on whale_29 Sept 2017 Siberian TimesA self-proclaimed science-based news site (LiveScience, 29 September) that picked up the story of this unique event had the temerity to suggest the bears might have been “hungrier than usual” due to global warming.

It deliberately conflates predictions of future starving bears due to low sea ice levels with this observation of many obviously not-starving bears checking out an attractive food source (my bold):

“It’s unclear, however, whether climate change had made these particular bears hungrier than usual. The frequency of starving polar bears is expected to increase as the climate warms and sea ice declines — not just because of climate change directly, but because ice loss is taking away seals, their main food source, Steven Amstrup, chief scientist at Polar Bears International, a nonprofit research organization dedicated to studying polar bears, told Live Science in 2015.”

Except that there is no evidence that ice loss is “taking seals away” — certainly not in the Chukchi Sea. Chukchi Sea seals have been found to be doing better with less ice than they were when there was more ice in the 1980s.

More below, including the location of Wrangel Island and sea ice maps.

UPDATE 2 October 2017: Sea ice in the Chukchi Sea has been lower this summer than over the last few years but the polar bears spending the ice-free season on Wrangel Island are still in good to excellent condition:

r02_Chukchi_Sea_ts_4km at 2017 Oct 1

Continue reading

Problem polar bears in Churchill at this date show 2017 less than 2016 and 2015

Comparing Churchill problem bear statistics over a few years provides some critical perspective: this year, the bears are causing much fewer problems.

This 2nd week in September is no exception, being the 9th week ashore in all cases: 2017 (4-10 September, where I think “total number of polar bear occurrence reports to date” should be 64, not 53, see week 7 report here), 2016 (5-11 September), 2015 (7-13 September), where there were about 1/2 the number of bears in “jail” this year compared to the last two years (i. e., 6 vs. 11 and 12) and slightly more than 1/2 the number of occurrence reports in 2017 than in 2016 and 2015 (64 vs. 107 and 99):

2017 week 9 Sept 4-11 may be typo

2016-sept-5-11_week-9.jpg

2015 Sept 7-13_at Sept 14

 

 

Churchill polar bear report 17-23 July 20: those ashore appear to be in great shape

Just out from the City of Churchill: few polar bears reported onshore for the week of 17-23 July 2017 (week 2) but those seen “appear to be in great shape.”
Churchill PB reports_week 2_ July 17-23_2017

Update 24 July 2017 12:20 PM: Just spotted this blog report from Churchill Polar Bears” that I somehow missed last week, which includes what seems to be the first polar bear photo’s of the season (of a sow and two chubby cubs) that are also in fine condition.

ChurchillPolarBearsDotOrg_July 14 2017 Alex De Vries photoThe photos were taken by Churchill photographer and guide Alex De Vries on Thursday 13 July and I hope he doesn’t mind my including one of those here as documentary evidence of the good body condition of this mother and both her cubs — see more photos at the Churchill Polar Bears blog post dated 14 July here.

Compare last week’s PB Alert report above to last year’s (below):

2016 July 18_24_week 2

Western Hudson Bay polar bears reportedly still on ice as of 17 July 2017

Today, polar bear biologist Andrew Derocher posted a progress report via twitter on the annual journey ashore of the Western Hudson Bay bears tagged by his University of Alberta research team that shows virtually all of the bears are still out on the sea ice.

Churchill_Polar_Bear_2004-11-15 Wikipedia

After months of gloomy reports on the state of the Hudson Bay sea ice, it’s clear from the map Derocher posted (below) that only one bear out of 12 still transmitting has come ashore so far, although he comments that “some tags haven’t reported lately” (the purple icons are ear tags put on males &/or young bears while the blue icons are collars put on adult females):

Oddly, the same comment was made almost a month ago about these same bears and the suggestion was made that these animals “may be swimming to shore”:

Money quote: Today Derocher remarked that “bears may be shifting behaviour to stay out on less ice” to explain why the tagged bears have still not come ashore as he expects them to do.

Perhaps if he used a different ice chart, it might make more sense (see below). However, the same thing has been happening year after year: WHB polar bears stay on the ice much longer than Derocher predicts but he does not change his expectations or the type of ice chart he uses to track the bears.

As I’ve pointed out before (because this is what field researchers have stated), polar bears have a tough time catching seals after about mid-June or so but they may still prefer to be on the sea ice than on land, even if it’s low concentration ice.

Continue reading

Labrador polar bears face a longer ice-free season than Hudson Bay bears, but do well

Pretty typical ice levels in both regions for this time of year – Davis Strait polar bears (especially those in Labrador) are still onshore while Hudson Bay bears (even those in the south) have their sea ice hunting platform back.

Davis Strait Hudson Bay freeze-up at Nov 25 2014_PolarBearScience

Funny thing is, the Davis Strait subpopulation may still be increasing despite a longer ice-free season than Western Hudson Bay. And bears in the south of that region – who spend the summer onshore in Labrador – have the longest ice-free season of all1 yet according to the latest survey they were even doing better than bears in northern Davis Strait.

That apparent paradox has an easy explanation – sea ice extent in late summer/early fall (length of the ice-free season) has much less of an impact on polar bear health and abundance than the state of the food supply in the spring. More seals in spring, polar bears do well; few seals in spring, polar bears starve.

Continue reading

“Meltdown: Terror at the Top of the World” — new book exploits polar bear attack to sell fear of sea ice decline

The polar bear attack that was all over the news last summer is now an ebook about global warming. The Maine lawyer who was mauled by a bear while on a hiking trip to Labrador (and lived to tell the tale) has allowed his story to be co-opted by an activist journalist to promote fears of sea ice decline, polar bear extinction, and man-made global warming.

Melt-down_Terror at the Top of the World_Nov 12 2014 press release book cover

The press release issued yesterday by the news group that published the book and employs author Sabrina Shankman (InsideClimateNews), described it this way:

“A riveting new e-book about the battle between man, beast and Nature in a warming world. Called Meltdown: Terror at the Top of the World, the e-book tells the story of the hikers’ harrowing encounter with a polar bear; of the plight of the polar bear in general, facing starvation and extinction as the sea ice melts and its habitat disappears; and of the Arctic meltdown, the leading edge of man-made climate change.”

I have little doubt the man mauled by the bear was indeed terrified and that his companions were as well. However, that horror is exploited shamelessly in this book as a means to promote anxiety over the future survival of polar bears and instill panic over a prophesied Arctic “meltdown.”
Continue reading

Polar bear attacks on humans – an evolutionary perspective

What with polar bear populations higher than they were 50 years ago and with many bears onshore during the ice-free season, a few polar bear attacks are to be expected – but how does the behaviour that drives those attacks compare with their closest evolutionary cousin, the grizzly?

Polar bear grizzly profiles_composite_Sept 15

I’ve done some summer reading on this topic, which I’ve summarized below. The results may surprise you.
Continue reading