Tag Archives: good news for polar bears

Good news about Chukchi Sea polar bears whispered by US Fish & Wildlife Service

Just out: the “accepted” version of the Rode et al. paper discussed here last month — detailing just how well polar bears in the Chukchi Sea subpopulation are doing, despite recent declines in sea ice.

However, what was decidedly odd was how I found out about it.

Yesterday (Aug 28), while looking for something else, I found a “press release” tweeted by World Wildlife Fund (WWF) employee Geoff York, who is now also a full voting member of the Polar Bear Specialist Group (PBSG).

Chukchi bears press release tweet_Geoff York Aug 28 2013

The announcement that York tweeted is listed as “alaska.fws.gov/external/newsroom/pdf/cs_polar_bear_article.pdf” and I found a stand-alone copy of the pdf with that title on Google.

However, FWS has so far (Aug. 29, 7:00 am PT) not mentioned this item on their [central] website, their twitter account, or their Facebook page (pdf here, with its original title). The “press release” has no date and is not on FWS letterhead but is authored by “Eric V. Regehr, U.S. Fish & Wildlife Service.” [I guess FWS employees can issue their own press releases?] UPDATE: Found it finally in the “FWS Alaska region” (Alaska FWS, posted Aug. 22, 2013, which included the Eric Regehr summary tweeted by York), via a news report at SitNews dated Aug. 27. Mystery solved]

Also odd that so far, no one except Geoff York himself seems to have picked it up (nothing so far on WWF website or Facebook page, Polar Bears International pages, or at ScienceDaily. [Update: see news report at SitNews dated Aug. 27. Still odd that the FWS report has been sitting there quietly since the 22nd (Thursday of last week)]

Not exactly how I’d choose to spread good news, but perhaps that’s the point.

Nevertheless, not too much new in the paper itself [contact me if you’d like a copy] – no population size estimate, for example – other than what I included in the summary provided last month (based on a March presentation by lead author Karyn Rode), except this: spring litter sizes [1.90 in 2007 and 2.17 in 2009 on Wrangel Island] were “are among the highest reported for 18 of 19 polar bear populations” and were similar to litter sizes 20 years earlier.

I guess the picture of the Chukchi female with a litter of triplet yearling cubs included without mention in the 2010 Rode and Regehr report (pdf here, copied below, discussed previously here) was significant after all.

Rode and Regehr 2010_Chukchi_report2010_Fig1_triplets_labelled

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Good news for polar bears: no early breakup of W. Hudson Bay sea ice this year

The sea ice chart provided by the Canadian Ice Service (Fig. 1 below) shows a lot of ice still present in Hudson Bay today, the last day of June, 2013.

Figure 1. Sea ice extent in Canada, June 30, 2013. From the Canadian Ice Service.

Figure 1. Sea ice extent in Canada, June 30, 2013. From the Canadian Ice Service.

This means we have long passed the point when breakup of the sea ice in Western Hudson Bay (30% ice concentration) could be considered ‘early.’ See Table 1 below for previous breakup dates (1991-2009) and previous post here for more details.

 Table 1. Breakup dates calculated for Western Hudson Bay, 1991-2009, using a new method described by Cherry et al. (in press). More details in previous post here.


Table 1. Breakup dates calculated for Western Hudson Bay, 1991-2009, using the new method described by Cherry et al. (2013, in press). More details in previous post here.

Since most polar bears don’t leave the ice until almost a month after the official breakup date is declared, it means that even if breakup for Western Hudson Bay occurs within the next few days, most polar bears would not start their summer fast until the beginning of August.

Regardless of when polar bear biologists decide that breakup has occurred, one thing is now clear — this will not be an early breakup year for Western Hudson Bay. That’s good news for polar bears.

And what about the rest of the Arctic? You’ll see from Fig. 2 below that as of yesterday (June 29), there was still ice present in each of the 19 polar bear subpopulation regions — more good news for polar bears.

Figure 2. Sea ice extent worldwide vs. polar bear subpopulations at June 29, 2013. On this date, there was still sea ice present in every one of the 19 subpopulation regions. Map on the left from US National Snow and Ice Data Center (NSIDC “MASIE”) here; map on the right from the Polar Bear Specialist Group, with labels added. Click to enlarge

Figure 2. Sea ice extent worldwide vs. polar bear subpopulations at June 29, 2013. On this date, there was still sea ice present in every one of the 19 subpopulation regions. Map on the left from US National Snow and Ice Data Center (NSIDC “MASIE”) here; map on the right from the Polar Bear Specialist Group, with labels added. Click to enlarge

References
Cherry, S.G., Derocher, A.E., Thiemann, G.W., Lunn, N.J. 2013. Migration phenology and seasonal fidelity of an Arctic marine predator in relation to sea ice dynamics. Journal of Animal Ecology 82(4):912-921.
http://onlinelibrary.wiley.com/doi/10.1111/1365-2656.12050/abstract