Tag Archives: tracking polar bears

Tracking polar bears in the Beaufort Sea – November 2014 map

Here is the November 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.”

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 November 2014 is copied below.

 Figure 1. Original caption: "Movements of 12 satellite-tagged polar bears for the month of November, 2014. Polar bears were tagged in 2014 on the spring-time sea ice of the southern Beaufort Sea. All twelve of these bears have satellite collar transmitters. Polar bear satellite telemetry data are shown with AMSR2 remotely-sensed ice coverage for 30 November, 2014." Click to enlarge, original here.


Original caption: “Movements of 12 satellite-tagged polar bears for the month of November, 2014. Polar bears were tagged in 2014 on the spring-time sea ice of the southern Beaufort Sea. All twelve of these bears have satellite collar transmitters. Polar bear satellite telemetry data are shown with AMSR2 remotely-sensed ice coverage for 30 November, 2014.” Click to enlarge, original here.

All twelve bears (all females) are finally visible on this map, confirming my suspicion that two were so close together they overlapped. Three out of the twelve “Southern Beaufort” bears were in the Chukchi Sea at the end of November (west of Point Lay, see discussion here). If you missed it, my October 2014 post on the progress of these bears has some maps from previous years that are worth reviewing.

Tracking polar bears in the Beaufort Sea – October 2014 map shows most ice since 2010

Here is the October 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.”

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 October 2014 is copied below (Fig. 1).

For the end of October, there was more ice in the Southern Beaufort this year than there has been since 2010.

Eight bears (all females) were on the ice and four were onshore. Only six of the eight on-ice bears were actually in the Southern Beaufort – the other two were in the Chukchi Sea (west of Point Lay, see discussion here).

Note that the recent boundary change between the Southern and Northern Beaufort subpopulations (the US/Canada boundary of the Southern Beaufort), reported here, has not addressed the fact that many western “Southern Beaufort” bears move into the Chukchi Sea. Continue reading

Tracking polar bears in the Beaufort Sea – September 2014 map

Here is the September 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.”

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 September 2014 is copied below (Fig. 1).

At the end of September, with sea ice starting to rebuild, it appears there were 8 bears on the ice and three on land.

The situation for September was not very much different from August, except that two of the 11 bears (up from one) were on the ice in the Chukchi Sea in September, a phenomenon that was recently acknowledged to have affected the last population estimate for the Southern Beaufort subpopulation.

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Tracking polar bears in the Beaufort Sea – August 2014 map

Here is the August 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.”

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 August 2014 is copied below (Fig. 1).

Compare this to July’s map (Fig. 4). The 20 bears from May (down to 13 in June) are now down to 11. All seven of the bears outfitted with glue-on satellite transmitters in April [either males or subadult animals] have either moved out of the area or their tags have fallen off or stopped transmitting. This means that all of the bears shown on the maps below are females.

At the end of August, nearing the minimum extent of ice for this year, seven bears were on the ice and only four were on land.
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Summer sea ice melt and polar bear maternity dens

The yearly sea ice minimum extent is almost upon us, which has recently been the seasonal signal for excitable biologists and their activist groupies to resume their breathless rants about what sea ice loss could mean for polar bears.

Polar bear den_CreditUSFWS_labeled

Never mind that the summer minimum extent reached in September, no matter how low it goes, is pretty much irrelevant to polar bear health and survival. As I’ve discussed before, what’s really important is the presence of not-too-thick ice during the spring, so they can catch lots of young seals and put on lots of fat.

But to a lesser degree, the extent at mid-to-late summer is important because this is when pregnant females that prefer to make their maternity dens on shore are looking for good places to spend the winter.

So the topic for today is this: how much does the extent of ice at the height of summer dictate where polar bear females make their winter dens?
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Tracking polar bears in the Beaufort Sea – July 2014 map and subpopulation boundary issues

Here is the July 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.”

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 July 2004 is copied below (Fig. 1).

Compare this to June’s map (Fig. 4). The 20 bears from May (down to 14 in June) are now down to 13. All seven of the bears outfitted with glue-on satellite transmitters in April [either males or subadult animals] have either moved out of the area or their tags have fallen off or stopped transmitting. This means that all of the bears shown on the June and July maps below are females.

One bear has moved into Canadian territory and another is well into the Chukchi Sea. This is now known to be a typical rather than unusual phenomenon, and is pertinent to the bigger picture of what constitutes a discrete geographic subpopulation for polar bears.
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Up to 20% of collared polar bears located on ice that officially does not exist, says the PBSG

Here are two more priceless quotes from the minutes of the last meeting of the IUCN Polar Bear Specialist Group (PBSG) – on issues with sea ice percentages used to define “ice-free” and the problem of bears with collars showing up on sea ice that, according to ice data, does not exist. These quotes are in addition to the ones I posted earlier this week (here and here).

Polar bear with collar and tag_USGS_labeled

See the original document for the context here.
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Tracking polar bears in the Beaufort Sea: June 2014 map

Here is the June 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.”

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 June 2004 is copied below (Fig. 1).

Compare this to May’s map (Fig. 2) – the 20 bears from last month are down to 14, and all seven of the bears outfitted with glue-on satellite transmitters in April [either males or subadult animals] have either moved out of the area or their tags have fallen off or stopped transmitting. This means that all of the bears shown on the June map below are females with satellite radio collars.
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Tracking polar bears in the Beaufort Sea – May 2014 map and USGS video footage

Here is the May 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.”

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 May 2014 is copied below (Fig. 1).

Compare this to April’s map (Fig. 2) – the 24 bears from April are down to 20 and the bears are spreading out a bit from the area on the central Alaskan coast where they were originally tagged. Fifteen of these bears have satellite collar transmitters [and therefore are females] and 5 of these bears have glue-on satellite transmitters [either males or subadult animals].

Some comments on the polar bear video cam footage released June 6 by USGS and stories on it run by the media follow.

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Tracking polar bears in the Beaufort Sea – more bears added to the April 2014 map

Polar bears were tagged in 2013 and 2014 on the spring-time sea ice of the southern Beaufort Sea. Seventeen of these bears have satellite collar transmitters and 7 of these bears have glue-on satellite transmitters” say the folks at the USGS Alaska Science Center.

I guess that’s why the April map was late getting posted.

Polar bear ear tag_USFWS_PolarBearNews2010

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