Tag Archives: USFWS

If summer ice was critical for S. Beaufort polar bears, 2012 would have decimated them

Posted on January 12, 2015 | Comments Off

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?

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

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Posted in Advocacy, Population, Sea ice habitat

Tagged abundance, aerial survey, Amstrup, Beaufort Sea, Bromaghin, Mark Serreze, mark-recapture, polar bear, population estimate, population recovery, Red list, Rode, sea ice, Southern Beaufort, spring ice conditions, summer ice minimum, USFWS

Challenging NOAA’s “Arctic Report Card 2014” on polar bears

Posted on December 19, 2014 | Comments Off

NOAA’s list of purported evidence for harm being caused to polar bears by Arctic warming is short and weak. It puts the gloomiest spin possible on the current well-being of an animal with all the earmarks of a healthy, well-distributed species.

This year, polar bears are virtually the only species that NOAA mentions in their Arctic Report Card – they’ve put all their icon-eggs in one leaky basket [what happened to walrus??]. But polar bears are doing so well that to make an alarming case for polar bears as victims of Arctic warming, many important caveats had to be left out or misrepresented. Some details given are simply wrong.

This year’s polar bear chapter was penned by IUCN Polar Bear Specialist Group chairman Dag Vongraven (you might recall his email to me earlier this year) and a polar bear conservation activist from Polar Bears International (whose battle cry for donations is “Save Our Sea Ice!”), Geoff York.

I challenge their four weak talking points one by one below.

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Posted in Population, Sea ice habitat, Summary

Tagged Arctic, Arctic Report Card, breakup, Bromaghin, cherry-picking, freeze-up, Geoff York, hybridization, IUCN Polar Bear Specialist Group, mark-recapture, polar bear, population estimate, red herring, sea ice, Southern Beaufort, thick spring ice, USFWS, Vongraven, western hudson bay

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

Posted on December 17, 2014 | Comments Off

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.
Continue reading

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

Posted in Advocacy, Conservation Status, Population

Tagged abundance, aerial survey, Amstrup, Beaufort Sea, Bromaghin, cherry-picking, IUCN, mark-recapture, models, PBSG, polar bear, population estimate, population recovery, Red list, Rode, satellite collars, sea ice, Southern Beaufort, USFWS, withholding data

Polar bear researchers knew S Beaufort population continued to increase up to 2012

Posted on November 19, 2014 | Comments Off

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.

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

Comments Off on Polar bear researchers knew S Beaufort population continued to increase up to 2012

Posted in Advocacy, Conservation Status, Population

Tagged abundance, aerial survey, Beaufort Sea, Bromaghin, cherry-picking, IUCN, mark-recapture, models, PBSG, polar bear, population estimate, population recovery, Regehr, satellite collars, sea ice, Southern Beaufort, thick spring ice, USFWS, withholding data