Category Archives: Life History

Polar bear habitat update for Canada at mid-February

Mid-February is the tail end of the winter fast for polar bears. Sea ice is approaching it’s maximum global extent but local maximum extents may vary. Most of the sea ice in Canada is locked in already but two regions still vary at this time of year: the Labrador Sea off Labrador and Newfoundland – where polar bears come to feed on an abundance of newborn harp seals – and the Gulf of St. Lawrence, where polar bears have not been spotted in more than 60 years. sea-ice-extent-canada-2017-feb-14_cis

There is almost certainly enough ice for harp seals to give birth in the Gulf this year, if the ice holds (despite some premature hand-wringing by seal biologists). There is more ice in the Gulf and off Newfoundland this year than there was in 2013 (see map below). Continue reading

New paper updates lack of trend in W Hudson Bay breakup/freeze-up dates to 2015

A newly-published paper shows that there has been no trend in the time Western Hudson Bay polar bears spent onshore between 2001-2015 due to sea ice conditions at breakup or freeze-up (previously available to 2010 only), despite the marked decline of global sea ice since 2007.

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Figure 3 from Castro de la Guardia (2017) showing freeze-up and breakup dates and ice-free days 1979-2015 for Western Hudson Bay. Figure with caption is copied below, with explanation of symbols.

Previously, a 2007 paper by Eric Regehr and colleagues for WHB bears up to 2004, which was used to support the US bid to list polar bears as ‘threatened’ with extinction, concluded that between 1984 and 2003, bears were spending 3 weeks long onshore than they did in the 1980s.

The big news from Castro de la Guardia (2017) is that polar bears spent longer onshore from 1979-2015 by … 3 weeks. That is, no change from the situation in 2004. Wow!

Note the population size of the entire WHB subpopulation has also not declined since 2004 and is currently estimated at about 1030, based on a 2011 aerial survey (Stapleton et al. 2014).

Thanks to Andrew Derocher for the heads-up tweet.

From the abstract (my bold):

We found that the ice-free period in this region lengthened by 3 ± 0.8 wk over the period 1979−2015. Polar bears migrated onshore 2 wk earlier and offshore 1 wk later in the period 2005−2015 than in 1980−1989.

Here is the region in question, illustrated by Fig. 1 from the paper:

castro-de-la-guardia-et-al-derocher-2017-fig-1a-locationThe significant information contained in this paper is breakup and freeze-up dates and length of the ice-free period data for 2010-2015, which has been unavailable until now. More excerpts and comments below, including Figure 3 with its caption. Continue reading

Svalbard polar bears thrive in part due to ringed seal pups in the spring pack ice

Few people know that Arctic ringed seals (Phoca hispida, aka Pusa hispida) give birth and breed in the offshore pack ice in the spring, as it is seldom mentioned by either seal or polar bear specialists.

While it is true that some ringed seals give birth in stable shorefast ice close to shore, many others give birth well offshore in thick pack ice – where polar bears also live and hunt in the spring but where few Arctic scientists ever venture – and the existence of pack ice breeding ringed seals is one of the reasons that polar bears are such a resilient species.

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Ringed seal pup in a snow cave, B. Kelly photo (Wikipedia).

As a consequence, despite fears expressed by Ian Stirling, low shorefast ice and associated snow around Svalbard this winter (and any time in the past) is not necessarily a hindrance to polar bear survival because there are ringed seal pups available out in the surrounding pack ice – where bearded seals also give birth.

Of course, ringed seals pups are also available to Svalbard polar bears in the shorefast ice in the Franz Josef Land archipelago to the east (see map below) but it is the pups born in the offshore pack ice that are of interest here. The existence of pack ice breeding ringed seals may be why Norwegian biologists do not currently monitor ringed seals in the Barents Sea, despite many years of poor ice conditions around Svalbard in spring – this simply is not a species of concern.

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The fact that distinct ringed seal ecotypes (or habitat-specific morphotypes) exist in the Arctic – one that gives birth and breeds in shorefast ice and another that gives birth and breeds in offshore pack ice, perhaps driven by competition for limited shorefast ice habitat – is a phenomenon a colleague and I discussed in a peer-reviewed book chapter published several years ago. Have a look at the excerpt below and see what you think.

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Polar bears onshore in Svalbard in most dangerous season for bear attacks

Yesterday marked the first report I’ve found for polar bears onshore this winter, in a potentially dangerous repeat of a pattern that has become all-too common in recent years (especially last year) with bear populations booming virtually everywhere (but especially around Svalbard).

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This is the leanest time of year for polar bears – fat Arctic seal pups won’t be available for another 2-3 months and meals for polar bears are hard to come by – and that makes the bears especially dangerous.

So, despite the marked lack of sea ice around Svalbard this winter, a female polar bear with two cubs were reported near the community of Longyearbyen (still enduring 24 hours of darkness) – on the west coast of the archipelago (see map above), where sea ice has been virtually non-existent for years (see map below).

Svalbard ice 2017 Jan 17_NIS.png

It appears these bears traveled overland from ice off the east coast. There is no mention in any of the reports that the bears were thin or in poor body condition, or had so far caused any of the problems for which desperately hungry polar bears are famous. However, one dog-sledding guide had a frightening encounter in the dark in this on-going saga that began over the weekend (details and photos below). Continue reading

Polar bear habitat update and attempts to spoil the good news for kids

The trolls are out in force at Amazon, posting negative reviews of my new book, Polar Bear Facts & Myths – they just hate it when credible scientists won’t promote a message of doom. It seems folks of this ilk truly want children to have nightmares about drowning, starving polar bears; they encourage kids to frantically turn out lights in a vain attempt to “Save The Sea Ice” while unbeknownst to them, the polar bears and seals prosper.

I expect those same fear-mongers will really hate my next book, due to be released early next week, because it presents the evidence in a way all readers will understand with the references to back it up. Polar bears and ringed seals are thriving despite recent losses of summer sea ice and there is seemingly a huge body of activists and scientists who don’t want people to know that simple fact.

Coming soon    Polar Bears: Outstanding Survivors of Climate Change

Back to polar bear habitat news, here is the sea ice map for 30 December 2016: Hudson Bay iced-over and lots of ice moving down southern Davis Strait:

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Compare to last year at this time, when polar bears did not die off in droves anywhere in Canada (or we would have heard about it) – remember that 2/3 of the word’s polar bears live in Canada:

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Polar Bear Facts & Myths now available and may arrive in time for Christmas

The first science book suitable for kids that tells the whole truth about polar bears and climate change is now for sale at Amazon.

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This beautiful, full color summary (44 pages, 8 x 10 inches) explains in simple terms why polar bears are thriving despite the recent loss of Arctic sea ice. It’s written in a question and answer format, in language that readers of all ages can understand (age 7 and up). The book takes a sensible, big-picture approach that many readers will appreciate and is based on the most up-to-date information available.

This is the perfect gift for some of the polar bear lovers on your gift list and if you act quickly (order here), your book may arrive before the 25th. At this time, only the paperback is available but some ebook versions should be out shortly. 

For purchasers for which a pre-Christmas delivery isn’t going to work (publication will be later in Europe; shipping is faster to eastern Canada and the US than to the west), I have provided a gift card you can download to print off and give in lieu of the physical book (kind of a placeholder until it arrives).

UPDATE: 18 Dec. 2016 Now listed at Amazon Canada and Amazon UK

Download gift card PDF HERE for Polar Bear Facts & Myths

Download gift card PDF HERE for Polar Bears: Outstanding Survivors of Climate Change  (coming soon, see below).

[Download Christmas gift cards, one per page, for both books here]

Check my book website for updates.

For adults & high school students (coming soon Now available)

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This color, fully-referenced polar bear science book is aimed at adults and high school students. Polar Bears: Outstanding Survivors of Climate Change is fashioned after the popular lecture with the same title I have given since 2009, which has been enthusiastically received by audiences with diverse backgrounds.

My book website now has full details of these new non-fiction books (along with a revised author biography) and will be updated regularly regarding formats and venues as they become available. Details for EATEN on that site has moved to its own fiction page.

Hudson Bay could be ice-free in winter within 5-10 years, says seal researcher

Ringed seal biologist Steven Ferguson, in a statement to a reporter from the Winnipeg Free Press, made one of the boldest predictions I’ve ever heard:

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“Hudson Bay could experience its first free winter within 5-10 years.”

You heard it here, folks. It appears Ferguson thinks Hudson Bay was never ice-free in winter even during the Eemian Interglacial, when the Bering Sea was ice-free in winter – something that has not come close happening in recent years (Polyak et al. 2010:1769).

Sounds like a bit of ill-advised grandstanding to me.

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