Tracking polar bears in the Beaufort Sea – one tagged bear left at year end 2015

I’ve combined the months of November and December for this post on USGS polar bear tracking in the Beaufort Sea because there’s not much to tell: there’s one tagged bear left and she’s going almost nowhere. Where’s the news in that?

Movements of 1 satellite-tagged polar bear female for the month of November, 2015; shown with sea ice coverage at 30 November 2015. This bear was tagged in the spring of 2015 in the Southern Beaufort Sea. See original image here and December movements below.

Actually, it does tell us something: this female is probably in a sea ice den, a relative common phenomenon in the Beaufort Sea. And she’s on ice that’s out over very deep water.

This bear is on ice over deep ocean rather than the continental shelf (see map below), and has moved little since the end of November (see December tracking map below), it is liking this female has made a maternity den on the sea ice. If so, she has probably given birth already: although many cubs are born in December and some as late as February, the scientific convention is to assign January 1st as the date of birth for all cubs of the year.

Courtesy the Arctic Council 2009, via Wikipedia. This bathymetry map clearly shows the shallow regions of the Arctic – note how shallow Hudson Bay is and how large the area of shallow continental shelf is off Russia, Norway and the Bering Strait. Find Banks Island in the western Canadian Arctic (hint: the NW Passage routes surround it): the USGS tagged bear is west of the northern shore of Banks Island, well offshore of the Alaska coast.

December location of this tagged USGS female below: the movement is almost certainly due to the movement of the ice itself.

Movements of 1 satellite-tagged polar bear female for the month of December, 2015; shown with sea ice coverage at 31 December 2015. This bear was tagged in the spring of 2015 in the Southern Beaufort Sea. See original image here and November movements above.

NOTE: This is the November and December 2015 follow-up to my post on the July 2013 track map for female polar bears being followed by satellite in the Beaufort Sea by the US Geological Survey (USGS) – “Ten out of ten polar bears being tracked this summer in the Beaufort Sea are on the ice.”