Tag Archives: sea ice

Polynyas are critical for polar bear spring feeding

Areas of open water or thin ice in spring are essential for the survival of Arctic species, as I emphasized in my recent peer-reviewed paper on polar bear ecology. Sea ice is still abundant in spring (April-June), which is the critical feeding period for polar bears: they must consume about 2/3 of the total calories they need for the entire year. Most of those calories come from newborn seals (ringed, bearded, and harp).

In southern areas, such as Hudson Bay and Davis Strait, virtually all of this feeding is completed by the end of May, making June a time of opportunistic hunting for most bears: if they find a seal, they will kill and eat it but if not, they can do without. That’s not just my opinion but the reason given by polar bear specialists themselves to explain why Southern Hudson Bay polar bear numbers had not declined in the 2000s despite a sudden increase in the ice-free season:

…even though break-up has advanced by up to 3-4 weeks in portions of Hudson Bay it still occurs no earlier than late June or early July so does not yet interfere with opportunities to feed on neonate ringed seal pups that are born in March-April in eastern Hudson Bay. Therefore, losing days or weeks of hunting opportunities during June and July deprives polar bears of the opportunity to feed on adult seals, but does not deprive them of the critical spring period when they are truly hyperphagic. [Obbard et al. 2016:29]

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Wandering polar bears are the new starving bears falsely blamed on climate change: Déjà vu

I said last year that wandering polar bears appeared to be the new ‘starving’ polar bears that were formerly the go-to victims falsely blamed on lack of ice due to climate change and here we are again. Polar bear specialists and their cheer leaders so seldom disappoint.

Although not one of the Canadian news outlets that reported on the fat polar bear that was shot after unexpectedly showing up on the Gaspé peninsula two weeks ago blamed this incident on global warming, a few days later The Guardian in the UK stepped up.

Of course it did. My own report of the incident is here, from 1 May 2022, in case you missed it (with sea ice charts, as always).

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Ancient polar bear remains explained by sea ice and polynyas: my peer-reviewed paper

My open-access, peer-reviewed paper on the ecology of ancient polar bears in relation to sea ice has just been published in Open Quaternary. It’s called ‘Polar Bear Fossil and Archaeological Records from the Pleistocene and Holocene in Relation to Sea Ice Extent and Open Water Polynyas’.

A unique compilation of more than 104 polar bear skeletal records from the Holocene and late Pleistocene shows that most ancient remains are associated with existing or ancient open water polynyas or the expansion of sea ice during past cold periods. This big-picture analysis indicates that as they do today, polar bears were most commonly found near polynyas throughout their known historical past because of their need for ice-edge habitats.

Read my longer summary below and download the paper here. This is a much-updated and expanded analysis based on an informal study I did in 2012.

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Big announcement coming this week

New peer-reviewed polar bear paper of mine coming out, likely Monday or Tuesday. Watch for it.

Explaining abundant polar bear sightings on the East Coast as an upshot of sea ice loss is absurd

Last week, a senior producer at CBC News, in order to concoct a timely story for ‘Earth Day’, attempted to explain the high number of sightings of polar bears this April in Newfoundland and Labrador, compared to the last two years, as a consequence of climate change and its handmaiden, loss of Arctic sea ice.

Title: ‘With an extinction threat looming, no wonder polar bears are at our door — and on the roof: there’s a grim reason why polar bears have been frequently showing up in coastal communities’. CBC News, 23 April 2022

The problem with this narrative is that the East Coast had much reduced sea ice in 2021 and virtually no polar bear sightings in Newfoundland and none in Labrador. There was more ice in 2020 than 2021 but also few bears. This year, ice extent was similar to 2020 for most of the region but polar bear sightings were up considerably.

In fact, the two years with the most sightings and problems with polar bears since 2008 were 2017 and 2018: in 2017, sea ice was exceptionally thick in April (although average in extent) and by June the sea ice was so thick and enduring that the Newfoundland fishing fleet couldn’t get out for spring openings; 2018 was another year of average sea ice extent and had even an even larger number of sightings than 2017, in Newfoundland especially (Crockford 2019:32). This suggests the sea ice vs. polar bear correlation on the East Coast since 2008 – if there even is one – may be the opposite of that stated in the CBC article: less ice usually means fewer bears onshore in Newfoundland and Labrador and more ice often means more bears.

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Whaling crews and their encounters with polar bears and sea ice in 17th century Svalbard

A new paper published today by Dagomar Degroot is a long but interesting historical account about sea ice and whaling in the 1600s around Svalbard that includes some details on interactions of whalers with polar bears (Figure 4 from the paper copied below). These were the early days of whaling in the Arctic: the wholesale slaughter of whales and polar bears didn’t happen until the 1800s.

The paper is open access, so free to download but I’ve copied the abstract and a short excerpt here.

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More fat polar bear sightings around homes on Newfoundland’s Northern Peninsula

Two recent incidents really remind me of the opening scene in my polar bear attack thriller, EATEN, and this time both were captured on film. They involved bears in good physical condition and luckily, no one has been hurt. There is still sea ice off the Northern Peninsula, which has brought the bears from the north.

On Sunday (10 April) in St. Anthony, a woman was alerted by her dog to what she though was someone on the front porch and found herself literally face to face with a polar bear when she opened the door; it then hopped up on her roof. The next day, in Goose Cove, a woman watched two bears (probably a female with a two year old male cub) explore the outside of a neighbour’s house and then walk across her driveway.

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Another polar bear on Fogo, this time on the south shore as sea ice surrounds the island

On Friday, 8 April, a polar bear was photographed on the south coast of Fogo Island, Newfoundland at a time when sea ice surrounded the offshore island. The bear, spotted near North Side Road near Stag Harbour, was non-threatening to the point of being totally chilled out, but attracted enough human attention to cause traffic congestion. Another sighting a little more than a week ago near Tilting on the east side of the island could possibly have involved the same bear.

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Sea ice average for March is the metric used to compare to previous winters

The average sea ice cover at the end of March is the metric used to compare ‘winter’ ice to previous years or decades, not the single-day date of ‘most’ ice. This year, March ended with 14.6 mkm2 of sea ice, most of which (but not all) is critical polar bear habitat. Ice charts showing this are below.

But note that ice over Hudson Bay, which is an almost-enclosed sea used by thousands of polar bears at this time of year, tends to continue to thicken from March into May: these two charts for 2020 show medium green becoming dark green, indicating ice >1.2 m thick, even as some areas of open water appear.

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Polar bear attempted to break down front door of house in Newfoundland with people inside

A frightening incident just after midnight on Sunday left a woman and her daughter on the Northern Peninsula of Newfoundland shaken when a polar bear tried to break down their front door. Luckily for them, the bear was not starving and therefore not persistent: it soon stopped without doing much damage and neighbours were able to drive it away from the house. Again, the premise of my polar bear attack thriller, EATEN, is that the bear could have gotten into the house if it had really been motivated by hunger to do so. And what if that had happened and there were no neighbours to call for help?

There is still abundant ice around the northern Peninsula (see below), and gov’t officials are warning residents to be wary of other bears reported in the region. A CBC story on the incident quotes local wildlife officials as saying they “generally receive between 30 and 60 calls about polar bears annually. There have been 10 this year so far.” However, as I’ve pointed out previously, it appears this has only been true since 2012 or so: lots of bears visiting Newfoundland and Labrador in the spring is a relatively new phenomenon.

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