In an update to an earlier story from last month about a male polar bear spotted near Kaktovik with a tight satellite radio collar, a Russian biologist has voiced some some serious criticisms of the use of these devises.
In another news outlet, Andrew Derocher has finally admitted publicly that the Kaktovik bear with the tight collar is a male and is”likely his” (Global News, 23 November 2015; “Is this polar bear really being choked by a research collar?”). The male bear appears to have been fitted with a collar some time between 2007 and 2011. The collar should have fallen off by now but hasn’t. Derocher suggested maybe the collar isn’t really too tight and the blood might not belong to the bear. And that if the bear really wanted the collar off, he “…will be able to remove it himself.”
The criticisms of the use of collars are well worth reading.
UPDATE 25 November 2015: Another CBC report, not much more useful information except confirmation this is a male bear.
On Aug. 27, 2012 sea ice extent dipped below the yearly minimum extent reached in 2007.
The sea ice at this point, a five-day average, was 4.1 million km squared and the lowest point reached since satellite records began in 1979. The National Snow and Ice Data Center (NSIDC) thought it was important enough to issue a press release.
There are sure to be more than a few media-hungry folks who will be moaning about the fate of the poor polar bears because of this report. Before people get too hysterical, a bit of rational perspective might be helpful.
Keep in mind that 4.1 m sq. km (Fig. 5) is about the size of Greenland (2.166 m km2) plus Mexico (1.972 m km2), or about the size of India (3.287 m km2) plus Pakistan (0.809 m km2), figures from Wikipedia.
It may be a ‘record’ low, but it’s still a lot of ice: 4.1 m km2 is not anywhere close to an ‘ice-free’ Arctic!
Arctic sea ice melts – or gets pushed out of the Arctic and then melts – every year, leaving various amounts behind. The ice lingering at mid-September adds to next year’s ‘multiyear’ ice.
The maximum extent is usually reached mid-to-late March. Have a look at how this ‘low extent’ developed from the March maximum this year. Even if you’ve looked at some of these maps, you may not have looked at them one after the other. I’ll compare these to the fall maps for 2007, after the Sept. minimum and discuss these in relation to polar bear habitat. Contineu reading
Posted in Life History, Population, Sea ice habitat
Tagged Amstrup, Durner, Ferguson, ice thickness, Mauritzen, Messier, Ovsyanikov, polar bear evolution, sea ice extent, summer ice minimum