Tag Archives: aerial survey

A new count planned for Southern Beaufort polar bears

I know I was not the only one that thought the last polar bear count conducted by the US Geological Survey (USGS) in the Southern Beaufort generated an untenable result but it appears that some of those challengers are in a position to demand a recount.

polar_bear_usfws_no date_sm

CBC News ran a story late last week announcing a plan is in the works to do an aerial survey of Southern Beaufort Sea polar bears across their entire range over two years starting in 2017 (11 March 2016, “Joint U.S.-Canada Beaufort Sea polar bear survey planned“).

With luck, this period will not include another bout of the same thick spring ice conditions that decimated the population in the mid-2000s (which many reporters concluded was due to reduced summer sea ice because that’s what leading biologists implied). Even if it does, lucky timing will not negate the fact that this population is routinely subjected to devastating population declines caused by natural changes to spring sea ice conditions from which they have recovered on numerous occasions. Continue reading

Discovery News spreads old misinformation about W. Hudson Bay polar bears

In a just-released Discovery News piece, Kieran Mulvaney (4 November 2015, “In the polar bear capital, an uncertain future) repeated three misleading statements about Western Hudson Bay polar bears that keep making the rounds, despite the fact they have been laid to rest by the latest scientific reports on  (Lunn et al. 2013, 2014; Stapleton et al. 2014). I reviewed these just a few weeks ago.

Western Hudson Bay bear, Wakusp National Park, August 2011.

Western Hudson Bay bear, Wakusp National Park, August 2011.

1) “Climate change is causing the bay’s ice to melt earlier and freeze later, causing bears to spend longer a shore.”

Not true. Lunn and colleagues stated explicitly that there has been no trend in either break up or freeze-up of WHB sea ice since 2001. Although there has been large variability in dates, that lack of trend that has continued to this year.

2 & 3) “As a consequence, Churchill’s polar bears are decreasing in number (from approximately 1,350 three decades ago to roughly 900-1,000 now) and in physical condition.”

This deliberately misleading statement avoids the fact that the latest surveys found roughly the same number of bears in 2011 as in 2004 (the estimate used by the IUCN Polar Bear Specialist Group for WHB is 1030) when different counting methods were taken into account. The ~900 bear estimate came from the mark-recapture survey, which left out a portion of the range that the aerial survey covered, hence the official estimate of 1030.

In addition, there has been no scientific assessment of body condition or cub survival since before the last population estimate in 2004 – polar bear “experts” keep telling journalists there are declines but have yet to produce any data to support those claims. The latest surveys did not collect data on body condition or cub survival.

Mulvaney’s misinformation is almost certainly the result of spending time in Churchill with activist Polar Bears International spokesperson Steve Amstrup and activist climate scientist Katherine Hayhoe doing webcasts (e.g. “Challenges of communicating climate change”).  

Mulvaney is clearly not a journalist or a science writer: if he was, he would do some research of his own and stop believing as gospel every word that activist scientists feed him. They are using him as a mouth-piece and sadly, Discovery News is buying it all and presenting it as science.

[Hayhoe, by the way, blocked me on twitter earlier this morning for making one observational comment, my first-ever to her account, in response to a conversation about polar bear population numbers. This is what I said that Hayhoe does not want her followers to know:

“Stop wanton slaughter, #’s go up, works for all species. S Beaufort #polarbear #s dipped due to thick spring #seaice”

Both statements are true and supported by scientific literature. But Hayhoe is all about “climate communication” which appears not to allow science to intrude.]

References
Lunn, N.J., Regehr, E.V., Servanty, S., Converse, S., Richardson, E. and Stirling, I. 2013. Demography and population assessment of polar bears in Western Hudson Bay, Canada. Environment Canada Research Report. 26 November 2013. PDF HERE

Lunn, N.J., Servanty, S., Regehr, E.V., Converse, S.J., Richardson, E. and Stirling, I. 2014. Demography and population assessment of polar bears in Western Hudson Bay, Canada. Environment Canada Research Report. July 2014. PDF HERE [This appears to be the version submitted for publication]

Stapleton S., Atkinson, S., Hedman, D., and Garshelis, D. 2014. Revisiting Western Hudson Bay: using aerial surveys to update polar bear abundance in a sentinel population. Biological Conservation 170:38-47. http://www.sciencedirect.com/science/article/pii/S0006320713004618#

Western Hudson Bay polar bear numbers are stable, no trend in ice breakup or freeze-up

This needs saying again: the latest study on Western Hudson Bay polar bears reveal the population has been stable since 2004 and there has been no significant trend in either breakup or freeze-up dates since 2001.

Triplets in Wapusk NP from McCall webpage 2013

Environment Canada and the IUCN Polar Bear Specialist Group concur that the current size of the WHB subpopulation is about 1030 bears. Documents found online indicate a new version of the 2013 WHB mark-recapture report (Lunn et al. 2013) is now available (Lunn et al. 2014) and that a new population survey is planned for 2016. A 2013 story based on false information produced by The Guardian that is still in circulation should be retracted.
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If summer ice was critical for S. Beaufort polar bears, 2012 would have decimated them

Did we hear a huge hue and cry in 2013 about starving polar bears and low cub survival in the Southern Beaufort Sea? No, we did not. Despite the record-breaking low summer sea ice extent the year before (2012), and despite the fact that USGS biologists were putting collars on polar bear females there the spring of 2013 (Rode et al. 2014), we heard not a peep about a polar bear catastrophe in the Southern Beaufort. Odd, isn’t it?

Sea ice extent 2012 Southern Beaufort_PolarBearScience

Several polar bear biologists and sea ice experts were busy late last fall suggesting to the media that a decline in polar bear numbers in the Southern Beaufort was due to declines in summer sea ice, which they blamed on global warming (see quotes below and earlier discussions here, here and here). However, they made no mention of the fact that the record-breaking September ice extent in 2012 did not seem to have any noticeable effect on polar bear health or survival in 2013.

Sea ice maps from the National Snow and Ice Data Center (NSIDC) tell most of the story about what the media were, and were not, told about summer sea ice in the Southern Beaufort between 2001 and 2013.  Continue reading

Recent S. Beaufort polar bear count was a cherry-picked result – new evidence

New evidence has come to light that mark-recapture field work used to calculate a new population estimate for Southern Beaufort polar bears did not conclude in 2010 as implied in a widely-publicized paper last month but continued until 2013.

Amstrup w triplet_Prudhoe Bay 2005_USGS_sm

Steve Amstrup in S. Beaufort, 2005 (USGS photo), co-author of Rode et al. paper.

As I discussed previously, last month’s widely-hyped paper (Bromaghin et al. 2015 in press) – which reported a decline of ~40% between 2004 and 2010 (based on spring mark-recapture work) – was contradicted by fall survey counts that suggested strongly a population rebound would have been apparent if the mark-recapture work had continued another two years.

A new paper by Karyn Rode and colleagues (which includes Bromaghin and others (e.g. Amstrup) from the previous paper), summarized in a USGS press release issued on Monday and published online Tuesday, utilized comprehensive data collected during mark-recapture work carried out in spring from 1982 to 2013 in the Southern Beaufort Sea.

This new paper used the same kind of comprehensive data as Bromaghin and colleagues – from the same season, in the same region – to assess potentially negative effects of the mark-recapture research method itself, up to 2012 and beyond.

More on the Rode et al. conclusions later1 – for the moment, what is important is that the work described in the paper confirms that spring mark-recapture work on polar bears in the Southern Beaufort continued beyond 2010. Bromaghin and colleagues didn’t end their mark-recapture work prematurely — they actually left data collected in 2011 and 2012 out of their population estimate analysis when they had to have known the population had not finished rebounding from the 2004-2006 decline.
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Polar bear researchers knew S Beaufort population continued to increase up to 2012

Why did the Southern Beaufort polar bear population survey stop in 2010? It’s clear that the recently-published and widely-hyped new study stopped before the population rebound from a known decline was complete.

USFWS 2013-2014 PB News_cover_PolarBearScience

The researchers of the recently-published paper knew before starting their mark-recapture study in 2007 that the population decline had taken place. They also knew why the numbers dropped and that previous declines, caused by similar conditions, had been followed by a full recovery.

Did they really think a full recovery in population numbers was possible in only three four years, when cubs born in 2007 would not yet have been old enough to reproduce?

In fact, a US Fish and Wildlife Service (USFWS) fall survey of Southern Beaufort polar bears in 2012 found numbers were higher than they had been in a decade.
Continue reading

Inuit resist government requests to tag and collar polar bears in MClintock Channel

Inuit residents of Cambridge Bay in the Central Canadian Arctic are resisting requests by the Nunavut Government to tranquilize, collar and tag polar bears to assist in their population survey.

“A female polar bear and her two cubs dash across the ice near Gjoa Haven, where the polar bear hunt has been limited for nearly 15 years. (PHOTO BY JANE GEORGE)” Story here, also by Jane George.

“A female polar bear and her two cubs dash across the ice near Gjoa Haven, where the polar bear hunt has been limited for nearly 15 years. (PHOTO BY JANE GEORGE)” Story here, also by Jane George.

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