Tag Archives: polar bears in winter

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.”

polar_bear with collar_USGS

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.
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Tracking polar bears in the Beaufort Sea – January 2015 map

Here is the January 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.”

Tranquilized_pb570_S Beaufort March 2014_USGS

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 January is copied below.

There are only 6 bears being followed now, which means a few more collars have failed, or the bears have moved out of the area or died.
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Tracking polar bears in the Beaufort Sea – December 2014 map

Here is the December 2014 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.”

Tranquilized_pb570_S Beaufort March 2014_USGS

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 December is copied below.

There are only 10 bears being followed now, which means a few more collars have failed, or the bears have moved out of the area or died.
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Polar bear habitat – more Arctic sea ice in Canada this week than in early 1970s

This week, Arctic sea ice in Canada, where 2/3 of the world’s polar bears live, had more sea ice than was present in the early 1970s. Globally, the ice is spitting-distance close to the 1981-2010 average calculated by the NSIDC for this date – which means lots of winter/spring hunting habitat for polar bears.

Canada sea ice freeze-up_same week_Dec 25 1971_2014 standard average

This is the peak of the polar bear birthing season (both in the wild and in zoos.) Newborns will be snug in maternity dens built by their mothers onshore or on the sea ice; the rest of the population will be out on the ice.

Sea ice extent 2014 Dec 25 NSIDC

Regional ice charts going back to the late 1960s and early 1970s for this week show even more surprises — have a look.

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Polar bears in winter – a seasonal review of insights and research

Here are summaries of my “Polar bears in winter” series. It’s an interesting recap of what polar bears do over the unimaginably cold and dark months of an Arctic winter.

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Hudson Bay sea ice well above average – excellent early December polar bear habitat

Sea ice development for this date is well above average on Hudson Bay – even more so than last week – making three years in a row of average-to-above average ice habitat available to polar bears in early December (see last week’s ice summary here). Coverage for the week of 11 December from 1971 to 2104 below (from Canadian Ice Service):

Hudson Bay freeze-up same week_Dec 11 1971_2014 w average

More maps below (from CIS and NSIDC), see others here.

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Polar bear habitat update – January 2014

Sea ice in the Arctic a bit below the 1981-2010 average for this date  but still within two standard deviations, with more ice than average off Canada — indicating we are still within expected natural variation, statistically speaking.

Remember that the National Snow and Ice Data Center (NSIDC) says this about standard deviation:

“Measurements that fall far outside of the two standard deviation range or consistently fall outside that range suggest that something unusual is occurring that can’t be explained by normal processes.”

Ice maps below, click to enlarge.

 Figure 1. Sea ice and lake ice concentration from the Canadian Ice Service (CIS) for 31 January, 2014. Note the amount of ice in the east, off Labrador (the “Davis Strait” polar bear subpopulation).


Figure 1. Sea ice and lake ice concentration from the Canadian Ice Service (CIS) for 31 January, 2014. Note the amount of ice in the east, off Labrador (the “Davis Strait” polar bear subpopulation).

Figure 2. Sea ice extent from the National Snow and Ice Data Center (NSIDC) for 29 January 2014. Note that the extent of ice in eastern Canada noted in Fig. 1 is slightly more than the 1981-2010 average (the orange line), while other areas have slightly less than average for this date. Compare ice growth over the last month to Fig. 3 below.

Figure 2. Sea ice extent from the National Snow and Ice Data Center (NSIDC) for 29 January 2014. Note that the extent of ice in eastern Canada noted in Fig. 1 is slightly more than the 1981-2010 average (the orange line), while other areas have slightly less than average for this date. Compare ice growth over the last month to Fig. 3 below.

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