Tracking west Alaskan polar bears in the Beaufort in October – all at Banks Is., CAN

Two out of three polar bear females that were collared by USGS researchers near Barrow, Alaska last spring are hanging out on the northwest coast of Banks Island, Canada. The other bear (bright green icon) appears to have been collared on the ice off Prudoe Bay in April. And as I discussed last month, it’s unusual for bears from the western end of the Southern Beaufort subpopulation (or even the central region) to end up in the Northern Beaufort subpopulation territory.

Original caption: “Movements of 3 satellite-tagged polar bears for the month of October, 2016. Polar bears were tagged in 2016 on the spring-time sea ice of the southern Beaufort Sea. All 3 of these bears have satellite collar transmitters. Polar bear satellite telemetry data are shown with AMSR2 remotely-sensed ice coverage from 29 October, 2016.” See full resolution image here and close-up below.

While it’s too early to say whether these females will den at this location for the winter (and have their cubs on Canadian soil), it looks highly likely at this point. Still, it’s possible there is some attractant onshore that’s keeping them there, like a beached whale, since all three moved into the region in July and have remained there ever since (previous months’ maps here).

The map below (courtesy the IUCN PBSG) shows the official subpopulation boundaries for this region, for national and international management purposes:

Sea ice has been lower than usual for recent years this fall but certainly not the lowest it’s been since 1968, as the CIS ice graph below shows – both 2012 and 1998 were lower and 2009 was almost as low (entire Beaufort region, CIS week of 29 October – the most recent available):

And if we look at just the Alaska region, this year is about as low as it was in 2012 and 1998 but surprisingly, 1968 was the next lowest (based on extrapolated data)(Alaska region of the Beaufort, CIS week of 29 October – the most recent available):

Here is the most recent ice map, for 5 November 2016 (CIS), showing the shorefast ice forming along the coast of western Alaska: