Spring in the Arctic is April-June (Pilfold et al. 2015). As late April is the peak of this critical spring feeding period for most polar bear populations, this is when sea ice conditions are also critical. This year, as has been true since 1979, that sea ice coverage is abundant across the Arctic for seals that are giving birth and mating at this time as well as for polar bears busy feeding on young seals and mating.
Below is a chart of sea ice at 25 April 2018, showing sea ice in all PBSG polar bear subpopulation regions:
Some Arctic subregions below, in detail. Continue reading
Posted in Life History, Sea ice habitat
Tagged Barents Sea, birth, facts, feeding, mating, polar bear, population size, science, sea ice, seals, spring, Svalbard, thickness
A statement yesterday from Yegor Vereshchagin, wildlife conservation manager from Chukotka, Russia (Polar Bears Adjust to Climate Change, 20 February 2018) confirms that Chukchi Sea polar bears are currently doing extremely well.
Contrary to previous reports and predictions (e.g. Amstrup 2011; Amstrup et al. 2007, 2008; Durner et al. 2009), there appears to be no threats due to recent declines in summer sea ice (Rode and Regehr 2010; Rode et al. 2013, 2014, 2018) or from poaching.
Posted in Conservation Status, Population, Sea ice habitat
Tagged Chukchi Sea, Chukotka, climate change, poaching, polar bear, population size, Russia, sea ice, triplets
New Scientist has an article coming out next week takes a fairly reasoned approach to the polar bear conservation issue. It acknowledges that polar bear numbers have not declined in recent years even though summer sea ice dropped dramatically but goes on to perpetuate a number of myths that might not have happened if the author had done his homework or quizzed his other experts as thoroughly as he did me.
The survivors: is climate change really killing polar bears? Rapid global warming is said to be ringing the death knell for polar bears, by melthing their icy hunting grounds. But the reality is more complex. Fred Pearce, New Scientist 10 February 2018. Online now.
Posted in Conservation Status, Hybridization, Population, Sea ice habitat
Tagged climate change, conservation, extinction, global warming, grizzly, grolar, hungry, hybrid, Pearse, pizzly, polar bear, population size, sea ice, starving, survivors
In scanning comments generated by the recent flurry of internet interest in polar bears and blogs I noticed that a good many people, fed alarming media stories, are still convinced that polar bear numbers are declining rapidly when nothing could be further from the truth.
Posted in Advocacy, Population
Tagged climate change, estimates, facts, global warming, good news, observations, population size, science, sea ice, status
Is there a mutiny in the works between the IUCN Red List and the IUCN Polar Bear Specialist Group (PBSG) over polar bear population estimates or has there simply been a breach of ethics? What else explains the fact that some of the subpopulation estimates used by the PBSG to support the status of ‘vulnerable’ for the IUCN Red List in 2015 are unacceptable to them in 2017? And why are the PBSG refusing to embrace the Red List global estimate of 22,000-31,000?
The latest version of the IUCN PBSG status table was posted online 30 March 2017 without fanfare or even a note on their home page. It seems the result came from much discussion at their official meeting last summer (June 2016) that they say continued into early March 2017.
PBGS members voted to reject four subpopulation estimates used in the 2015 Red List polar bear status review — even though the inclusion of those numbers was required in order for the Red List status of ‘vulnerable’ to be upheld. The group has also chosen not to update their global population page with the Red List estimate of 22,000-31,000.
And surprise, surprise — now that only one subpopulation out of nineteen worldwide has shown a recent decline, the PBSG have removed the “trend” columns from their summary table for subpopulations.
Welcome to conservation ‘science’ practiced by IUCN polar bear specialists.
Posted in Advocacy, Conservation Status, Population
Tagged Chukchi Sea, conservation, count, East Greenland, ethics, IUCN, Kara Sea, Laptev Sea, polar bears, population size, Red list, science, status, unknown
Polar bear numbers have risen since 2005, no matter how you look at it:
USGS estimated 24,500 (average) polar bears in 2005.
IUCN estimated 26,500 (average of 22,000-31,000) in 2015
(assessment completed in July, released in November).
Subpopulation surveys completed or reported after July 2015 (Baffin Bay, Kane Basin, Barents Sea) added ~2,000 bears.
This brings the adjusted average total at 2015 to ~28,500.
This may not be a statistically significant increase but it is also not the catastrophic decline that was predicted to occur in association with the abrupt drop of summer sea ice in 2007 to a new average of about 3-5 mkm2 [updated 1 June 2017].
Explained in full in this published paper, pgs 20-21:
Crockford, S.J. 2017 V3. 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 2 March 2017. Doi: 10.7287/peerj.preprints.2737v3 Open access. https://doi.org/10.7287/peerj.preprints.2737v3