Last week biologist Andrew Derocher recently implied via twitter that less sea ice in the eastern portion of the Southern Beaufort (SB) this year at mid-May is harmful to polar bears (calling it “a hole in the ice where polar bears used to live“), but both long-term and short-term data don’t support such a glass-half-empty interpretation.
Not only does spring breakup of sea ice in the SB normally begin with such open patches of water (see the video above from last year) — driven by the powerful currents of the Beaufort Gyre, not ice melt (explained in detail here) — it may actually be necessary for the survival of local seals, polar bears and whales in spring and early summer (Citta et al. 2015; Crawford et al. 2015; Harwood et al. 2015; Stirling et al. 1981).
As I’ve pointed out before, the biggest threat to SB bears is thick sea ice in spring and its associated late breakup, a 2-3 year-long phenomenon unique to this region known to have occurred about every 10 years since the early 1960s (well documented in the scientific literature) but which has not (as far as I know) happened since 2004-2006.
In other words, a considerable patch of open water and less concentrated ice in the eastern SB around Cape Bathurst is almost certainly a good thing for this particular subpopulation (see previous post here for an in-depth discussion) because historically, when a polynya of some extent has not formed by April or May it has been devastating for local marine mammals.
The fact that an extensive patch of open water existed at mid-May in this region last year and the year before (2015 and 2016) — with no public hue-and-cry about a great dying of SB bears from Derocher or anyone else — suggests that open water in the eastern SB this year is likely to be beneficial for SB polar bears, or at least benign. Continue reading
Posted in Life History, Population, Sea ice habitat
Tagged bearded seals, Beaufort Gyre, Cape Bathurst, Derocher, hole in the ice, polar bear, polynya, ringed seals, sea ice, shore leads, Southern Beaufort, thick spring ice
A few days ago in a radio interview, a senior US Fish & Wildlife biologist repeated the tall tale that Southern Beaufort Sea polar bear numbers declined in recent years due to loss of summer sea ice. But restating this egregious misinformation does not make it true.
The Southern Beaufort population did decline between 2001 and 2006 but it was due to natural causes (thick ice in spring from 2004 to 2006) – it had nothing to do with recent summer sea ice loss and Eric Regehr knows it.
There is no evidence that the population decline continued after 2006, so it cannot be said to be still declining. Moreover, the situation in the Southern Beaufort does not support the predictions made by Regehr and his colleagues that polar bear populations will decline precipitously if summer sea ice declines further.
My recently published paper demolishes the message of doom for polar bears and the misinformation it’s based upon: it’s free and written in straight-forward scientific language.
Crockford, S.J. 2017. Testing the hypothesis that routine sea ice coverage of 3-5 mkm2 results in a greater than 30% decline in population size of polar bears (Ursus maritimus). PeerJ Preprints 19 January 2017. Doi: 10.7287/peerj.preprints.2737v1 Open access. https://peerj.com/preprints/2737/ (pdf here).
Here’s an excerpt of the nonsense broadcasted on KNOM Radio Alaska by Regehr and transcribed for their website (29 January 2017) [my bold]: Continue reading
Posted in Advocacy, Population, Sea ice habitat
Tagged advocacy, Eric Regehr, hypothesis testing, KNOM, misinformation, polar bear, poster child, predictions, Regehr, Southern Beaufort, US Fish and Wildlife Service
PBS has published a bizarre poor-starving-polar-bears story that uses pictures of fat, healthy bears to illustrate the supposed desperation of malnourished bears of the Southern Beaufort Sea that is blamed on declining sea ice.
The photo of the fat bear above, taken by the Kaktovik resident quoted in the 15 October 2016 PBS story, Polar bears, growing desperate for food, threaten native Alaskans, accompanies this statement:
“While images of malnourished polar bears have become a national symbol of the effects of climate change, they are a front line reality for Native Alaskans, who face them on their own property and do not want them to get hurt.”
Except this is not a story about starving bears but too many fat bears hanging around one particular community looking for other kinds of food – after being lured in by the enticing smell of rotting whale meat left onshore by the residents.
If photos of starving Beaufort bears existed that PBS could have used to illustrate this story, I’m certain those photos would have been used. But virtually all of the pictures I’ve seen of Kaktovik bears are the epitome of health – fat and sassy – but none that could be described as starving.
It turns out that while native Kaktovik residents have profited from tourists and journalist who have shown up in droves to view the large numbers of bears attracted to the bone piles left after butchering summer-caught bowhead whales, the bears have also put the community at risk of personal attack and loss of stored food. Who would have thought?
Residents of Kaktovik (see map below) have unwittingly enticed these polar bears ashore and now must deal with the consequences. As the residents of Churchill discovered decades ago, having polar bears close to your community comes with benefits, problems – and danger.
There is no doubt that Kaktovik has a polar bear problem but it cannot plausibly be blamed on anthropogenic global warming, retreating sea ice, or starving bears – an irresistible attractant close to the community is the cause and solutions must be found to keep residents safe and their food secure. The PBS article discusses a few of those solutions. Some quotes and background below.
Posted in Life History, Polar bear attacks, Sea ice habitat
Tagged Atwood, Barter Island, bone piles, climate change, desperate, facts, fat bears, global warming, Kaktovik, malnourished, polar bears, retreating sea ice, sea ice, Southern Beaufort, starving, stressed
Even though it is well known that subadult male polar bears (≤ 4 years old) continue to grow in mass and bulk as they mature – so that their thick necks get even larger – in recent years Andrew Derocher and his students at the University of Alberta potentially endangered the lives of many subadult males in the Southern Beaufort in the process of learning relatively little they didn’t already know.
Money quote from a just-accepted paper by Master’s student Jody Pongracz and supervisor Derocher (“Summer refugia of polar bears (Ursus maritimus) in the southern Beaufort Sea” Polar Biology, in press 2016):
“The number of bears tracked varied over time due to collar design, deployment, and both planned and unplanned collar retention.”
So, how much “unplanned collar retention” issues [collars that did not fall off as expected] went on during this 2007-2010 study? They don’t say.
Is this paper saying U of A researchers knew they had ‘collar retention’ issues as far back as 2010 but continued to deploy them on subadult males after that study was over? It seems so, because they had an issue with just such a bear last year.
The bear with an apparently tight collar that was photographed last fall (see photo above) went out onto the ice and no one knows what happened – there has been no more information on him since, although researchers have apparently been watching for him, updated just yesterday). The University of Alberta statement says (under the June 2 update):
“Ongoing research at the University of Alberta is shifting to ear tag radios as required”
So now they realize that putting collars on subadult males is not such a good idea. Brilliant!
CBC News (28 October 2015): “Photo shows polar bear injured by tight radio collar“. See previous posts here and here. In a Global News interview (23 November 2015), Derocher admitted his team had “likely” put the collar on that bear, prompting the University of Alberta to issue a “Q & A” statement on the incident – which continues to insist that failure of collars to release is “rarely seen.”
Posted in Life History, Sea ice habitat, Uncategorized
Tagged Andy, Derocher, failures, problems with collars, satellite collars, sea ice, Southern Beaufort, subadult males, thick spring ice, tight collar, University of Alberta
Take-home quote from a new polar bear paper by Todd Atwood and colleagues (2016):
“…there is no causal link between the patterns in polar bear vital rates and increased use of terrestrial habitat…”
In other words, there was no information to link the increased time polar bears spent onshore with either an increase or a decrease in body condition, survival or cub production. The authors did find that polar bears were strongly attracted to the bone piles that accumulated in the fall from 2010-2013 after Inuit bowhead whale (Balaena mysticetus) hunting at Barrow, Cross Island, and Kaktovik. Isn’t that a surprise?
The results also appear to confirm previous work that showed terrestrial (land-based) foods are not important to polar bears – a conclusion I totally agree with and which I discussed last year here. No wonder there was no press release issued by USGS about this study. It’s only “news” because someone the Anchorage Daily News interviewed lead-author Atwood yesterday as a way of promoting the International Bear Conference (see previous post here, now updated with a link to the Talk of Alaska radio podcast). Atwood implied there could be advantages to bears from feeding on the bone piles but admitted he had no data to support that assumption.
Posted in Advocacy, Life History, Population
Tagged Atwood, bone piles, Cross Island, decline, Kaktovik, polar bear, population size, sea ice, Southern Beaufort, terrestrial foods, whale carcasses
The evidence that polar bears have not been harmed by recent declines in sea ice is contained in the scientific literature, no matter what some researchers say when they talk to the media.
Here’s a few of those facts (not all, by any means), with the references to back them up:
Posted in Advocacy, Conservation Status, Sea ice habitat, Summary
Tagged Amstrup, Beaufort Sea, climate change, facts, global warming, polar bear, sea ice, Southern Beaufort, threatened, USGS
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.
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.
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