A recent study by Norwegian biologist Karen Lone and colleagues, who tagged 57 polar bear females with sensors around Svalbard, discovered that polar bears can dive to a maximum depth of 13.9m and can swim long distances across open water without rest. Contrary to previous claims, polar bears are excellent divers and their breath-holding ability did not seem to limit how deep they could dive.
From the abstract of the new paper by Lone and colleagues (Lone et al. 2018):
“Some bears undertook notable long-distance-swims. Dive depths up to 13.9 m were recorded, with dives ≥5 m being common. The considerable swimming and diving capacities of polar bears might provide them with tools to exploit aquatic environments previously not utilized.”
Compare the above statement to one made by Stirling and van Meurs (2015), after describing a 3 minute dive video-taped during an aquatic stalk of a bearded seal, also in the Svalbard area:
“…increased diving ability cannot evolve rapidly enough to compensate for the increasing difficulty of hunting seals because of the rapidly declining availability of sea ice during the open-water period resulting from climate warming.” [my bold]
These two papers really show the difference between using anecdotal accounts as if they were evidence of species-wide physical abilities and doing a scientific study on the physical ability of interest.
Posted in Advocacy, Life History, Sea ice habitat
Tagged continuous swims, depth, dive, harbour seals, polar bear, Spitsbergen, stalk, Stirling, Svalbard, swimming, underwater
A dead polar bear was found on the shore of northeastern Newfoundland yesterday but the cause of death has not yet been determined.
From the local Telegram (5 June 2017):
“[Ann] Peddle of Bristol’s Hope was out for her morning walk when she came across the carcass of a polar bear that had washed ashore. The carcass had drifted between the rocks near the wharf in Bristol’s Hope, according to Peddle.
Peddle took some quick photos of the bear to post to social media before contacting the wildlife department at around 8:30 a.m.”
Ann Peddle took the photo below, which was printed with the above story:
See the map below for the location of Bristol’s Hope in NE Newfoundland, along the west shore of Conception Bay (see map at end of post for the names of the bays):
Was this a death by drowning or some other, more likely cause?
Posted in Life History, Sea ice habitat
Tagged ashore, Bristol's Hope, Conception Bay, death, drowning, injury, Newfoundland, polar bear, sea ice, starvation, swimming, walking
A polar bear female accompanied by a cub recently attempted to board a small sailboat anchored in a remote harbour off central Labrador – giving the two American boaters below deck a mighty big surprise.
‘He said ‘it’s a bear, it’s right on the boat, make some noise.'” – Nancy Zydler
The encounter occurred south of the same national park where a much-publicized attack occurred in July 2013 (see previous posts here and here) but had a happier ending. See more below from a CBC report released this morning (based on a radio interview) and some ecological context for the sighting not mentioned by the reporter.
Posted in Polar bear attacks, Population, Sea ice habitat
Tagged attacks, Davis Strait, encounters, harp seals, Labrador, Meltdown, polar bear, prey, problem bears, sailboat, sightings, summer, summer fast, swimming, Torngat Mountains National Park
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.
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
Just look at the polar bear on the cover of my new novel (right sidebar) and image that bear coming towards you with no intention of stopping. That’s what a Newfoundland RCMP officer faced yesterday – and he did what he had to do.
This is the usual time for polar bear visits to northern Newfoundland but this one had a sad ending. The bear that came ashore at Deep Cove (where some of the action in my novel EATEN takes place, near the artist studio pictured in the photo shown above) on Fogo Island (map below) was killed by RCMP due to fears for public safety when it kept approaching officers even after warning shots were fired.
Maps and quotes from the 2 May CTV report below:
UPDATE 4 May 2016: more detailed (and accurate) information added below from a new CBC report – apparently, the bear was a large juvenile male, not an adult as originally reported, and was larger than initial reports indicated.
Posted in Polar bear attacks, Sea ice habitat
Tagged attack, Davis Strait, Eaten, Fogo, Newfoundland, polar bear, problem bears, RCMP, sea ice, swimming
The air is thick with desperation on the polar bear front:
“[Andrew] Derocher said the polar bear population in the Beaufort Sea has fallen more than 50 per cent in the past 10 years.
“So it is a concern that this is probably one of the factors associated with the population decline,” he said.
As the CBC report in which this quote appears states immediately afterwards, there is no evidence for such a thing in the paper under discussion:
“The study found no direct evidence of that – all polar bears appeared to survive the swims recorded in the study.”
There is no truth to Derocher’s first statement either. Desperation – you don’t have to be a scientist to sense it. And the media wonder why people don’t trust them…
Posted in Uncategorized
Tagged Beaufort Sea, Derocher, desperation, Earth Day, facts, hype, Michaels, polar bear, population crash, sea ice, swimming
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.
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