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
Walt Meier, sea ice scientist at NASA Goddard, made a statement yesterday about this year’s ice conditions [2016 Climate Trends Continue to Break Records: July 19, 2016]:
“It has been a record year so far for global temperatures, but the record high temperatures in the Arctic over the past six months have been even more extreme,” Meier said. “This warmth as well as unusual weather patterns have led to the record low sea ice extents so far this year.“ [my bold]
Well, except for Davis Strait/Labrador Sea this spring. And Western Hudson Bay/Foxe Basin this month – plus the fact that late July sea ice in the Laptev Sea is higher than it’s been for more than a decade (more on that below).
I guess totals matter for some things – just not for polar bears. However, it’s nice to see the issue of melt ponds get some attention, since they are such a prominent feature of polar bear habitat during the summer melt season.
Posted in Life History, Sea ice habitat
Tagged accuracy, Beaufort, Chukchi, extent, ICEBRIDGE, Laptev Sea, melt ponds, NASA, Northeast Passage, satellite radio collars, sea ice, summer
I’ve already commented on the 2013 update of polar bear population status released by the IUCN Polar Bear Specialist Group (PBSG).
However, I thought it might be interesting to graph the changes in global population estimates over time (from 1981-2013) — not just the actual estimates from PBSG status tables (with their min/max error ranges) but those totals plus the so-called “inaccurate” estimates that the PBSG have dropped from their accounts in recent (2005-2013) assessments: Chukchi Sea, East Greenland, Queen Elizabeth Islands (now known as the “Arctic Basin”), and Laptev Sea.
In 2001, those “inaccurate” estimates contributed 5,000-5,400 bears to the global total, but now they’re gone — no bears from those regions contribute to the official totals listed on recent PBSG status tables.
Adding those dropped estimates back into the global totals makes it possible to generate a graph in which the global estimates are truly comparable over time.
To see how the dropped estimates influenced the perception of population change over time, I’ve also graphed the estimates given by the PBSG in their status tables. I’ve combined the two into one image (Fig. 1, click to enlarge) to make comparison easy.
UPDATE 5 December 2014: Links to more recent posts relevant to this issue added below. The most recent numbers, added 31 May 2015, are here.
UPDATE 26 March 2019: See “Latest global polar bear abundance ‘best guess’ estimate is 39,000 (26,000-58,000)”
Posted in Conservation Status, Population
Tagged Chukchi, East Greenland, estimate, graph, Laptev Sea, PBSG, polar bear, polar bear numbers, Polar Bear Specialist Group, population decline, population estimates, population increase, population over time, Queen Elizabeth Islands, Rode, stable population, status tables, timeline
It’s hard to imagine ancient people successfully hunting polar bears in any numbers – armed as they were with the simplest of bone and stone weapons. Archaeological evidence supports the impression that ancient Arctic hunters rarely took polar bears – there are a few polar bear bones, but not many, in most archaeological sites across the Arctic that were occupied over the last 10,000 years (see my Annotated Map of Ancient Polar Bear Remains of the World).
There is but one exception to this pattern: Zhokhov Island in the East Siberian Sea, Russia (see Fig. 1 below). Almost four hundred polar bear bones were recovered from two of the 13 semi-subterranian houses discovered on the island, well-preserved by permafrost for over 8,200 years. It is by far the largest – and the oldest – collection of polar bear bones left by human hunters anywhere in the world and it is described in a fascinating paper published in 1996 by Vladimir Pitul’ko and Aleksey Kasparov [contact me if you’d like to see it].
Zhokhov Island is situated just above 760N latitude and so has about the same length “winter’s night” as the northern tip of Novaya Zemlya, where William Barents and his crew spent the winter of 1596/97 (see previous post here ) – about 2 months, from early November to early February. The average January temperature today in the archipelago of the New Siberian Islands is −280C to −310C.
The East Siberian Islands are included in the Laptev Sea subpopulation of polar bears, the only Russian region that contributes a count (800-1,200 bears) to the global population estimate, based on an aerial survey conducted in 1993 (see previous post here).
Figure 1. Map of the New Siberian Islands off Siberia, with tiny Zhokhov Island circled. Map from Wikipedia