Category Archives: Life History

Longest-swimming polar bear lost less weight than if she had stayed onshore

Posted on May 3, 2016 | Comments Off

Recent media hype over swimming polar bears in the Southern Beaufort has been quite spectacular (still going strong today at the Washington Post here) but a close look at relevant data shows the message is bogus. Researchers admit (in their methods section) they couldn’t tell if bears said to have swum “non-stop” actually hauled out for half a day or more to rest on small ice flows invisible to satellites and astonishingly, the bear getting all the media attention – who swam the longest of any bear – lost less weight than a bear would have done simply sitting on shore for the same length of time.

Washington Post_swimming polar bears_snapshot 21 April 2016

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Posted in Advocacy, Conservation Status, Life History, Sea ice habitat

Tagged Beaufort Sea, claims, facts, Hudson Bay, longest swim, media hype, melting ice, misinformation, non-stop swims, polar bear, sea ice, swimming, weight loss, without rest

Polar bear habitat update end of April 2016: Plenty of sea ice for feeding

Posted on April 28, 2016 | Comments Off

So, here we are near the end of the first month of the Arctic spring and there is still more ice than usual off Labrador and conditions in the Barents Sea are improving daily. The fear-mongers can blather all they like about the potential risks of bears swimming in summer – but spring is the critical season as far as sea ice is concerned for polar bears and all polar bear biologists know it. Polar bears consume 2/3 of all the food they need for the year during April-June and so far, ice conditions are looking just fine.

Cambridge Bay_we re OK_from Joe Prins

There is enough ice where there needs to be ice for polar bears to gorge themselves on new-born ringed and bearded seals – and that’s really all that matters. More ice off Labrador means more hunting ground for the Davis Strait polar bears that depend on the tens of thousands of young harp seals born this year off the Front.

Harp seal pup_DFO Newfoundland
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Posted in Life History, Sea ice habitat

Tagged bearded seal, facts, feeding, harp seal, hunting, Labrador, polar bear, polynya, ringed seal, sea ice, Southern Beaufort, Svalbard

Most Beaufort polar bears swim from ice floe to floe during breakup, study shows

Posted on April 19, 2016 | Comments Off

swimming3_USGS

You may have seen the headlines in Canadian news outlets over the last 2 days.
“Polar bears swimming farther as sea ice recedes, study shows”

“Melting sea ice forces polar bears to swim longer, farther: study” [“Bear biologist Andrew Derocher says the forced swims are particularly hard on mothers with young cubs”]

“Polar bears swimming longer, farther because of melting sea ice, study finds”

Oddly, none of the above news reports said where the paper was published or mentioned the name of the lead author – only University of Alberta co-author Andrew Derocher was interviewed (see the only press release I could find here, issued by the San Diego Zoo where the lead author is now employed).[update: CBC ran another story a day later that corrected these omissions]

But what did the study actually say?

Significantly, no bears died while swimming during the two lowest sea ice extent summers since 1979 and no evidence was presented that swims were “particularly hard on mothers with young cubs.” The quotes from the paper below sum it up for Beaufort Sea (BS) bears (the inclusion of Hudson Bay (HB) bears in this study seems gratuitous and potentially misleading, since only a few swam anyway – only 15 out of 59):

“….91% (91/100) of the swims in the BS occurred before the annual September minimum sea ice extent had been reached. …In the BS, 81% (29/36) of swims started and ended in pack ice…”

So, despite what may be implied during media moments, Beaufort Sea polar bears were not frantically trying to reach the sea ice from land so that they could attempt to keep feeding over the summer – most of their swimming was done during breakup in July and August from one bit of pack ice to another and they showed no evidence of harm from doing so. Map from the study and more quotes below.
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Posted in Life History, Sea ice habitat

Tagged Beaufort, Derocher, forced swims, Hudson Bay, mothers with young cubs, Pilfold, polar bear, receding sea ice, sea ice, summer, swim longer, swimming, swimming further

Tracking polar bears in the Beaufort Sea – new crop of tagged bears for 2016

Posted on April 9, 2016 | Comments Off

Five more bears were tagged near the Southern Beaufort Sea coast last month, all in the western portion of the coast where Chukchi Sea bears are often encountered. They join the one female who seems to have made a den way out over the continental shelf, where she’s been all winter.

putting_collar_on_polar_bear_slider_USGS

This is the March 2016 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.”

Five tagged bears are relatively few compared to eight last spring, and thirteen in 2013 [added to 7 from the previous year for a total of twenty, which were down to 13 by June] but the same as five tagged in 2014. This spring, three of the USGS tagged bears have glue-on transmitters, which means they are either males or juvenile bears rather than females (which are fitted with collars):

“In collaboration with the U.S. Fish and Wildlife Service we are also experimenting with glue-on and ear tag satellite transmitters, which can be deployed on adult male bears and younger, still-growing bears.”

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Posted in Life History, Sea ice habitat

Tagged Barrow, Beaufort Sea, glue-on transmitters, ice thickness, sea ice, tagging, thick spring ice, tracking polar bears, USGS

Polar bear visits Newfoundland community of Goose Cove

Posted on April 8, 2016 | Comments Off

Goose Cove on the Great Northern Peninsula, western Newfoundland, had a polar bear visitor onshore yesterday. That’s typical for this region at the this time of year. The bear wasn’t seen, reported the Northern Pen (8 April 2016), but resident Jim Rice, who spotted the bear tracks in the snow, had this to say:

“I put my boot into one of the tracks, and I wear a size 12 boot, and it was the whole way around my boot,” said Rice. “So I didn’t stick around too long after that because I didn’t know if it was still in the area.”

Polar bear foot_USFWS_PolarBearNews2013

Goose Cove is featured in my polar bear attack thriller, EATEN in which polar bears come ashore much earlier than usual because their food source has failed – and terrorized the northern coast. A scarier story than well-fed bears ashore in April, after feeding for a month or so on harp seal pups.

Map below, from my novel, as well as sea ice conditions at the time.
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Posted in Life History, Polar bear attacks

Tagged attacks, Goose Cove, Newfoundland, onshore, problem bears, sea ice

Late winter surge in sea ice habitat and the resilience of Svalbard polar bears

Posted on March 31, 2016 | Comments Off

The Barents Sea – and Svalbard in particular – has had very little sea ice this winter but recent evidence suggests pregnant females adapted by moving east to Franz Josef Land to have their cubs. The surge in ice that’s come over the last few weeks will, however, be welcome habitat for the critical hunt of fat newborn seals that takes place primarily in April and May.

Svalbard polar bear_NP015991-isbjorn-JA

It was only last fall that Norwegian biologist Jon Aars (photo above taken by him in August 2015) was touting the fat condition of Svalbard-area polar bears he and his team saw in August and admitted the population had increased by a whopping 42% since 2004 – despite dire predictions of a drastic decline. In fact, 2014/2015 was a great year for the area’s polar bears.

However, in the fall of 2015 sea ice was so late forming around Svalbard that it seemed impossible that any females would get to traditional denning grounds on the east coast in time to give birth. There was no sea ice to speak of until late December, so it seemed virtually certain that all females had gone to Franz Josef Land further east (in Russia) – as they are known to do – to utilized its alternative denning sites.

It’s called resilience – the ability to shift behaviour in response to changing conditions. In this case, all indications are that shifting den locations to Franz Josef Land is a long-standing response of Svalbard area polar bears to low ice conditions. This shift does not even require a movement outside their subpopulation boundaries, let alone a movement outside the ill-defined “sea ice ecoregions” originally defined by Steven Amstrup and colleagues (2008) to support their prediction that polar bears will likely be extinct by 2100, taken up later by others since.

Some polar bear specialists appear to believe that if Barents Sea conditions are not precisely what they were in the 1980s (examples here and here), polar bears cannot possibly survive. But the bears are showing them otherwise – and demonstrating how they likely survived previous warm periods like the Holocene Optimum ~9,000 years ago and the Eemian Interglacial ~115,000-130,000 years ago (CERQA 2014:66) without population numbers getting anywhere near extinction levels.
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Posted in Life History, Sea ice habitat

Tagged Aars, Barents Sea, cubs, declining sea ice, ecoregrions, El Nino, extinction, facts, habitat, polar bear, sea ice, Svalbard, threatened

Condition of S Hudson Bay polar bears varies with freeze-up only says new study

Posted on March 23, 2016 | Comments Off

Despite the fact that the polar bears of Southern Hudson Bay (SHB) live further south year round than any others, a recent study found their average body weight has declined relatively little since the 1980s. There has been no decline in the size of the population over that time either. Perhaps that’s why there was neither a press release nor a massive media blitz when this paper came out earlier this month.

James Bay female and cub_Ontaro Govt

Remarkably – despite what we are told about how critical breakup dates are to polar bear health and survival in Hudson Bay – this study found that for SHB bears, the small decline in body condition index correlated only with freeze-up dates, not breakup dates or length of the ice-free season. They also found that regional breakup and freeze-up dates relevant to polar bears in this area was the day when ice cover reached 5% (not 50%).

In other words, SHB polar bears left the ice (or returned to it) when the average ice cover near the coast was about 5%. This finding is yet more evidence that the meteorological definition of “breakup” (date of 50% ice cover) used by many researchers (see discussion here) is not appropriate for describing the seasonal movements of polar bears on and off shore.

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Posted in Life History, Sea ice habitat

Tagged body condition, breakup, defining breakup, facts, freeze-up, Obbard, polar bear, sea ice, Southern Hudson Bay

Polar bears onshore in winter – will more bears mean more deadly attacks?

Posted on March 19, 2016 | Comments Off

Incidents of polar bears causing problems onshore this winter (January & February) – including one that killed a horse in Greenland and another that threatened a resident in western Hudson Bay (only weeks after several incidents in southern Labrador) may be the tip of a very scary iceberg. I’ve taken a look at what records exist of this phenomenon, which in the past often involved deadly attacks. The large number of reports this winter appears to be a real increase, which is a rather terrifying prospect indeed.

Doug Clark photo polar bears onshore in Feb 2013 Wapusk NP

In winter, all polar bears except females in dens nursing newborn cubs are presumed by biologists to be on the sea ice hunting but it turns out that is not quite true. Although relatively rare over the last twenty years or so, it appears that in some areas, bears are now coming ashore in winter.

The photo above shows a polar bear photographed by a remote camera installed at Broad River Camp, Wapusk National Park, western Hudson Bay on 7 February 2013. It was visible to the camera for 40 minutes but apparently caused no trouble (camera installed and maintained by associate professor Doug Clark from the University of Saskatchewan and colleagues).

Given the fact that there are now many more polar bears than there were in the 1970s as well as more people living in many coastal Arctic communities, problems with bears in winter are likely to increase, as this winter’s events show. More bears out on the ice in winter (January-March) will almost certainly create more competition for the little bit of food that’s available (seals are hard to catch in winter), which means some bears might increasingly be looking for alternate sources of food onshore.

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Posted in Life History, Polar bear attacks, Population

Tagged attacks, conflicts, consequences of conservation, hungry, killing, onshore, polar bear, population increases, problem bears

Worrywart biologists fuel media fearmongering over winter sea ice levels

Posted on March 8, 2016 | Comments Off

Have you heard the old adage, “Don’t buy trouble”? I’m thinking we could use a lot more of that attitude from polar bear and Arctic seal biologists these days.

Gulf St Lawrence ice conc 7 March 2016_CIS

In an interview with CBC News yesterday, Department of Fisheries and Oceans Canada (DFO) seal specialist Mike Hammill fed the fear the media wanted to hear while admitting this year’s low ice levels in the Gulf of St. Lawrence will not affect harp seal numbers significantly (7 March 2016, “Lack of ice means fewer seal pups off the Magdalen Islands this year: Researcher says impact on overall herd limited, but ice patterns over time could be concern”).

Harp sea newborn_wikipedia

And University of Alberta’s Andrew Derocher has been busy tweeting his heart out that slightly lower than average sea ice levels this winter could mean a “challenging” spring for some polar bears – as if spring isn’t always challenging for some bears (especially young bears that are inexperienced hunters and low in the social hierarchy – meaning bigger, older bears often steal their kills – and old bears that are running out of steam).
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Posted in Advocacy, Life History, Sea ice habitat

Tagged buying trouble, Derocher, facts, Gulf of St. Lawrence, Hammill, harp seals, Labrador Sea, Newfoundland, polar bear, sea ice, spring ice conditions, winter maximum

Polar bear habitat update: Labrador sea ice highest in 20 years

Posted on February 26, 2016 | Comments Off

Sea ice off the southern Labrador coast hasn’t been this high for this date in 20 years: that’s great news for the harp and hooded seals that will give birth at the Front in another few weeks – for a while anyway, because a bumper crop of baby seals is also good news for the polar bears who gather there to eat them.

Sea_ice_near_coast_of_Labrador_-a_wikipedia sm