Tracking polar bears in the Beaufort Sea – February 2015 map

Here is the February 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.”

See that post for methods and other background on this topic, and some track maps from 2012 (also available at the USGS website here). The USGS track map for February 2015 is copied below.

There were 7 bears in February, up from 6 in January, because one of the bears has re-entered the area from elsewhere. However, many bears from the original sample have either had their collars fail, moved out of the area and stayed out, or they have died. We can’t tell from which of those options, or combinations of them, explain the reduced number still being followed.

Note the teal green track in Figure 1 below, streaking across the offshore pack ice — she’s the bear that’s come back from a sojourn out of the region (perhaps the Eastern Beaufort). Note all of these bears with collars are females.

Figure 1. Movements of 7 satellite-tagged polar bears for the month of February, 2015. Polar bears were tagged in 2014 on the spring-time sea ice of the southern Beaufort Sea. All seven of these bears have satellite collar transmitters. The teal-green track was not present in January. Polar bear satellite telemetry data are shown with AMSR2 remotely-sensed ice coverage for 28 February, 2015. Click to enlarge. Original here.

Compare this year’s map to last year in February, and to January 2015, copied below.

Figure 2. “Movements of 6 satellite-tagged polar bears for the month of January, 2015. Polar bears were tagged in 2014 on the spring-time sea ice of the southern Beaufort Sea. All six of these bears have satellite collar transmitters. Polar bear satellite telemetry data are shown with AMSR2 remotely-sensed ice coverage for 31 January, 2015.”
Click to enlarge. Original here.