polarbearscience

Polar bears in winter – a seasonal review of insights and research

Posted on December 16, 2014 | Comments Off

Here are summaries of my “Polar bears in winter” series. It’s an interesting recap of what polar bears do over the unimaginably cold and dark months of an Arctic winter.

Polar bear gives birth in Munich zoo, with photos and video (from January 8, 2014)

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Posted in History, Life History, Polar bear attacks

Tagged Arctic winteric, Barents, birth, body condition, De Veer, polar bear, polar bear attacks, polar bears in winter, shelter dens, survival, winter darkness

Hudson Bay sea ice well above average – excellent early December polar bear habitat

Posted on December 11, 2014 | Comments Off

Sea ice development for this date is well above average on Hudson Bay – even more so than last week – making three years in a row of average-to-above average ice habitat available to polar bears in early December (see last week’s ice summary here). Coverage for the week of 11 December from 1971 to 2104 below (from Canadian Ice Service):

More maps below (from CIS and NSIDC), see others here.

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Posted in Sea ice habitat

Tagged Canadian Ice Service, Churchill, Davis Strait, December, Hudson Bay, National Snow and Ice Data Center, polar bear habitat, polar bears, polar bears in winter, problem bears, sea ice, western hudson bay

W Hudson Bay polar bear mark-recapture study report 2013 – at last

Posted on December 10, 2014 | Comments Off

I have finally secured a copy of the 2013 Western Hudson Bay mark-recapture study produced by Environment Canada.

The pertinent figure is below: as you can see, there was no declining trend in Western Hudson Bay polar bears between 2000 and 2011. Click to enlarge.

I have relatives visiting so I don’t have time to do an in-depth summary but the report’s opening “Summary” is copied below and a pdf provided. More later when I have had time to look at it more closely. Background on the issue here.

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Posted in Advocacy, Conservation Status, Population

Tagged Canadian Wildlife Service, Environment Canada, Lunn, mark-recapture, misleading, Nunavut, polar bears, population estimates, Regehr, stable population, Stirling, western hudson bay, withholding data

Public misled about W Hudson Bay bears since November 2013

Posted on December 8, 2014 | Comments Off

Leading polar bear biologists knew by November 2013 that mark-recapture studies showed the Western Hudson Bay subpopulation had not changed appreciably since 2004 but none said so. This includes Steven Amstrup and Ian Stirling at Polar Bears International, Andrew Derocher (University of Alberta), and Nick Lunn (Canadian Wildlife Service), all of whom are (or have been) extensively involved in Western Hudson Bay polar bear research and have made recent statements to the media on this topic.

More details have emerged about the status of Western Hudson Bay (WHB) polar bears (reported a few days ago here), reported this morning in NunatsiaqOnline, excerpts below.

The story reveals that there are two Canadian Wildlife Service (Environment Canada) reports containing population estimates of Western Hudson Bay polar bears – one produced in 2011 and another in November 2013 (reversing the 2011 conclusion) – that have not been made public.

[In contrast, Nunavut Government reports on their 2011 population estimate, based on aerial surveys, were made public in both draft and final report formats (and have since been peer-reviewed and published)]

The conclusion of the 2013 report, quoted in this mornings article, suggests that some of our most vocal polar bear specialists have been misleading the public about the status of the Western Hudson Bay population for the last year.
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Posted in Advocacy, Conservation Status, Population

Tagged Amstrup, Canadian Wildlife Service, Derocher, Environment Canada, Lunn, mark-recapture, misleading, Nunavut, polar bears, population estimates, stable population, Stirling, western hudson bay, withholding data

Tracking polar bears in the Beaufort Sea – November 2014 map

Posted on December 7, 2014 | Comments Off

Here is the November 2014 follow-up to my post on the July 2013 track map for female polar bears being followed by satellite in the Beaufort Sea by the US Geological Survey (USGS) – “Ten out of ten polar bears being tracked this summer in the Beaufort Sea are on the ice.”

See that post for methods and other background on this topic, and some track maps from 2012 (also available at the USGS website here). The USGS track map for November 2014 is copied below.

Figure 1. Original caption: "Movements of 12 satellite-tagged polar bears for the month of November, 2014. Polar bears were tagged in 2014 on the spring-time sea ice of the southern Beaufort Sea. All twelve of these bears have satellite collar transmitters. Polar bear satellite telemetry data are shown with AMSR2 remotely-sensed ice coverage for 30 November, 2014." Click to enlarge, original here.

Original caption: “Movements of 12 satellite-tagged polar bears for the month of November, 2014. Polar bears were tagged in 2014 on the spring-time sea ice of the southern Beaufort Sea. All twelve of these bears have satellite collar transmitters. Polar bear satellite telemetry data are shown with AMSR2 remotely-sensed ice coverage for 30 November, 2014.” Click to enlarge, original here.

All twelve bears (all females) are finally visible on this map, confirming my suspicion that two were so close together they overlapped. Three out of the twelve “Southern Beaufort” bears were in the Chukchi Sea at the end of November (west of Point Lay, see discussion here). If you missed it, my October 2014 post on the progress of these bears has some maps from previous years that are worth reviewing.

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Posted in Sea ice habitat

Tagged Alaska, Beaufort Sea, Chukchi Sea, polar bear habitat, polar bear movements, polar bears, satellite collars, sea ice, Southern Beaufort, tracking polar bears, USGS

Western Hudson Bay polar bear population is stable: press release

Posted on December 5, 2014 | Comments Off

Slowly but surely, word is leaking out: the Western Hudson Bay polar bear population is stable at ~1000 bears, confirming the good news contained in maps posted on the Environment Canada website a few months ago (discussed by me here and here). Environment Canada has apparently been giving presentations in local Western Hudson Bay communities relaying their decision.

Courtesy IUCN PBSG

Yesterday, a press release was issued by one of the official Inuit organizations in Nunavut announcing the new official status of the Western Hudson Bay polar bear population.
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Posted in Conservation Status, Population

Tagged Arviat, climate change, Environment Canada, healthy polar bears, Inuit, Nunavut, polar bear, population status, western hudson bay

Hudson Bay sea ice above average for this date – more good news for polar bears

Posted on December 4, 2014 | Comments Off

It’s only the 4th of December and Hudson Bay ice formation is way up over late 2000s coverage for this date — and higher than 2012, which had the lowest overall September ice extent for the Arctic since 1978.

This means boom times for Western and Southern Hudson Bay polar bears as sea ice formation is several days to a week ahead of last year. And as I mentioned in my last post, average November ice coverage across the Arctic this year was higher than 2003. Don’t forget that 2/3’s of the world’s polar bears live in Canada (see recent status update here; map below).

Figure 4. The Davis Strait (DS) subpopulation region runs from just below the Arctic Circle at the north end to at least 470N in the south. About half of DS lays at the same latitude as Western Hudson Bay (WH). Courtesy Environment Canada.

Polar bear population status in Canada. Courtesy Environment Canada.

More maps and charts below.
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Posted in Sea ice habitat

Tagged baffin bay, CIS, Davis Strait, Foxe Basin, freeze-up, historical sea ice record, Hudson Bay ice formation, ice extent, NSIDC, polar bear, polar bear habitat, sea ice, Southern Hudson Bay, western hudson bay

Polar bear habitat update – November 2014 average sea ice levels higher than 2003

Posted on December 3, 2014 | Comments Off

Average polar bear habitat for November 2014 was well within two standard deviations¹ and higher than 2003, according to the November report from the National Snow and Ice Data Center (line and labels added, below).

Notice that the lowest average November level occurred in 2006 — not 2007 (after the second lowest September extent since 1978) and not 2012 (after the lowest September extent since 1978). Take note that the scale on the graph above does not go to zero but to a whopping ~9.5 million square km!

Quotes from the NSIDC monthy report and sea ice maps for November 2014 and 2 December 2014 below.

UPDATE 3 December 2014: CIS has issued a new ice map corrected for ice level on Hudson Bay – new map below.
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Posted in Sea ice habitat

Tagged arctic sea ice, Chukchi Sea, CIS, Davis Strait, Hudson Bay, NSIDC, polar bear, polar bear habit, sea ice extent, September ice minimum, standard deviation

Amstrup knows his polar bear predictions are flawed – but continues to promote them

Posted on November 29, 2014 | Comments Off

The largest conservation organization in the world says that predictive models developed by polar bear biologist Steven Amstrup are utterly unsuitable for scientifically estimating future populations. Earlier this year, mathematical modeling experts at the International Union for the Conservation of Nature, who maintain the Red List of Threatened Species, made it clear that Amstrup’s models (used in 2008 to convince the US Fish and Wildlife Service to list polar bears as ‘threatened’ due to predicted global warming) do not meet IUCN standards.

I’d say this makes Amstrup’s polar bear projections (Amstrup et al. 2008, 2010) no more scientifically useful than a crystal ball prophesy, but you wouldn’t know it by his recent actions — or the silence of his fellows.

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Posted in Advocacy, Conservation Status, Sea ice habitat

Tagged Amstrup, Bayesian models, conservation, crystal ball, data deficient, ESA, extinction, IPCC, IUCN, models, PBSG, polar bear, Polar Bear Specialist Group, predictions, Red list, Resit Akçakaya, sea ice, threatened, vulnerable

Davis Strait polar bear habitat – the sea ice is forming, but it’s late!

Posted on November 29, 2014 | Comments Off

Since 1971, there have been only two years with as little sea ice in Davis Strait as there was this year at this time – 2003 and 2010. But the ice is forming rapidly and history shows it will likely catch up enough by next week to allow most Davis Strait polar bears to start hunting seals except along the Labrador coast.