Polar bear mating season winds down with lots of sea ice habitat available

Habitat for polar bears is abundant worldwide as the prime feeding season passes its peak and mating season for sexually mature bears winds down.

Battle among polar bear males for the right to mate, from this 2011 DailyMail story here.

There is much more ice than usual around Svalbard in the Barents Sea and off Newfoundland and southern Labrador, home to ‘Davis Strait’ bears. There have been no media reports of polar bears onshore anywhere (since the third week of April in Newfoundland and late January in Svalbard).

Sea ice map below for 12 May 2017:

Compare the extent and concentration of ice around Svalbard above (at 12 May 2017) to conditions that prevailed on the same date in 2015 (below), considered a “good ice” year for local polar bears (and the year of the last population size count which registered an increase over the 2004 count):

There hasn’t been this much ice in the area at this point in the season for many years, especially to the north of Svalbard, and levels since late April have been above even the long-term average (disregard the huge downward blip, which is clearly a sensor malfunction of some kind):

In fact, ice is pretty solid throughout the Barents Sea and East Greenland at this time:

Across the Atlantic, the situation is similar, with unseasonably heavy sea ice off eastern North America and the Southern Beaufort Sea.

Sea ice levels off Newfoundland this year in the first week of May have not been so heavy in more than two decades — only 1991 had more ice — and this has been severely affecting local fishermen along the north coast, many of whom have been unable to get their boats out to start spring fishing (a phenomenon which last occurred in 2007):

Sea ice is just beginning to melt on Hudson Bay and Southern Beaufort but not off Labrador and Newfoundland:

But last year, melt was further along at this point in time, in all three of those regions:

Similarly, in 2015:

Compare the above to late May 2013, when there was no ice off Newfoundland, open water off Churchill in Western Hudson Bay, and only a hint of melt in the Southern Beaufort:

So, the implied message that unusually bad current ice conditions are to blame for a number of polar bears in poor condition sighted by polar bear specialist Andrew Derocher and his research team over the last few weeks (on the sea ice off Churchill and to the north) really stand out as yet another odd comment.

#polarbear seal kill. I've never seen seals so fully consumed but never seen so few kills in an area. Tough hunting conditions so it eat up. pic.twitter.com/6v90x709BV

— Andrew Derocher (@AEDerocher) April 30, 2017

and

This adult male #polarbear was NE of Churchill today. In crappy ice but he managed to kill a bearded seal. He was in OK shape but not great. pic.twitter.com/JAdOb6a1XA

— Andrew Derocher (@AEDerocher) April 28, 2017

and

Last #polarbear of @ualbertaScience 2017 spring season: very poor shape. Over 34 years, I've never seen bears in such poor shape in spring. pic.twitter.com/mqReTPsKZu

— Andrew Derocher (@AEDerocher) May 9, 2017

Communities in Western Hudson Bay had a lot of snow in March, especially Churchill.

Consequently, more bears than usual in poor condition in spring are a good indication (in my opinion) that deep snow over ringed seals birthing caves have negatively affected the availability of ringed seal pups for hungry bears in that region (thick snow hides the pupping lairs well, making them much harder for bears to find).

There may also be fewer ringed seals in general. A marked decline was noted after the late freeze-up in 2010, a phenomenon noted by seal researchers based on data up to 2013 (see Ferguson et al. 2017 paper here), and which may have recurred with late freeze-up in 2016. But as Kelsey Eliasson pointed out last month, 2016 was a strong El Nino year and the last time one of those hit in 1998, Churchill area polar bears in Western Hudson Bay bears also did not fare well — but they did recover when conditions moderated over the following years (more on WHB bears later).

Worldwide, there is still about 13 million km2 of sea ice habitat for polar bears (zoom in on the original here), since there are no bears in the Sea of Okhotsk: