Andrew Derocher
@AEDerocher
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Professor of Biological Sciences @UAlberta. I've studied polar bears for over 40 years. Author of Polar Bears: A Complete Guide to Their Biology and Behavior.
Edmonton, Alberta, Canada
Joined October 2014
Hudson Bay polar bears are quite south. February is a lean month & most bears just maintain condition until April-June when they put on most of their fat in preparation for the summer fasting period. Insights in April when @ualbertascience researchers are on the ice.
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RT @friendsofuofa: Join us on Tuesday, February 11 at Blue Chair for Raise the Bar with Andrew Derocher presenting "Polar Bears: A Culturalโฆ
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Western Hudson Bay polar bears are spread widely west to east & all are in the southern 1/2 of the Bay. It's an unusual distribution but it was an unusual freeze-up. It's a lot of extra walking to get that far east & return in the coming months & it uses a lot of energy.
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Polar bears in Hudson Bay are very spread out this winter. We're doing the analyses on our long-term tracking data to assess if nearshore vs. offshore distributions affect body condition: moving farther has an energetic cost but could be offset by energy intake.
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New paper examines the 50+ year history of polar bear research in Western Hudson Bay. It's dedicated to Ian Stirling (1941-2024) who kept the program running despite major challenges (i.e., funding) for decades. [open access]
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Hudson Bay sea ice almost normal & polar bears we're tracking are spread out. Conditions further east, however, in Labrador are potentially devastating for polar bears (no ice). There's no bear monitoring there now so we'll not know what's happening until locals provide insight.
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@JenKtn I understand the issues. You can also find me on Bluesky. I'm also looking to Instagram for more polar bear focussed content.
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@archerdairy @CousineauAlbert Once temperature drops to ca. -20 C (-4 F), sea ice forms pretty quickly. It's -30 C right now in Churchill. Polar bears will be plenty happy with that but the wind is howling at up to 64 km/h & most bears curl up and wait for the wind to drop in such conditions.
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Western Hudson Bay polar bears are very dispersed. Unusually so. It's been a strange year for the bears with a late breakup, slow freeze-up & a lot of missing ice in the east. I'll have a better sense of how the bears are doing when field work out on the ice starts in April.
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@Zoogai I'd be happy to hear about your thought on it. I call it "the book of the lost summers". It was a major undertaking but my goal was to make polar bear natural history accessible. I hope it works for you!
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Hudson Bay still missing a lot of sea ice. The bay is normally covered by January. Not great for polar bears in the east. A greater concern is the near total absence of ice along Labrador & about 2200 polar bears live there: maybe fjords are providing habitat but grim overall.
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Sea ice loss = habitat loss for polar bears. For a polar bear-centric view, the average polar bear uses 100,000 to 300,000 sq. km as their home range every year, it's a lot of lost habitat since 1979. The loss varies a lot by population: some seriously affected, others less so.
Since 1979, December has lost 1.98 million square kilometers (764,000 square miles) of sea ice, which is equivalent to 3 times the size of Texas. Read more in our latest sea ice analysis:
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Peter Thompson was a co-supervised PhD student in my research group. A rising star in quantitative ecology. @P_R_Thompson - now studying killer whales.
๐๐๐บ๐ฎ๐ป ๐ฟ๐ฒ๐ฐ๐ฟ๐ฒ๐ฎ๐๐ถ๐ผ๐ป ๐ฝ๐๐๐ต๐ถ๐ป๐ด ๐๐ต๐ฒ ๐ณ๐ผ๐ฟ๐ฒ๐๐โ๐ ๐น๐ฎ๐ฟ๐ด๐ฒ๐๐ ๐ฐ๐ฎ๐ฟ๐ป๐ถ๐๐ผ๐ฟ๐ฒ๐ ๐ณ๐๐ฟ๐๐ต๐ฒ๐ฟ ๐๐ต๐ฎ๐ป ๐ฝ๐ฟ๐ฒ๐๐ถ๐ผ๐๐๐น๐ ๐๐ต๐ผ๐๐ด๐ต๐ New study by Colleen Cassady St. Clair and former postdoctoral fellow Peter Thompson shows that grizzly bears and wolves stay hundreds of metres away from the busiest human-use trails, making important habitats unlivable. Human recreation on mountain trails is displacing grizzly bears and wolves from their natural habitats, even when the trails are hundreds of metres away, according to a new study from the University of Alberta. The research underscores the need for more effective planning to ensure that recreationists and wildlife can coexist, particularly in the busy Bow River Valley, which has long served as a natural corridor connecting the prairies to the Continental Divide. #UAlberta
#Research
#WildlifeConservation
#HabitatProtection
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Western Hudson Bay polar bears are enjoying the New Year well spread out near the middle of the Bay (more or less). They can't go much further east although they don't have to as seals are spread far & wide. We've added eat tagged bears (purple) handled in conflict in Churchill.
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There's still significant missing polar bear habitat in eastern Hudson Bay. Conditions in Hudson Strait (north of Quรฉbec) & along Davis Strait (off Labrador) are also in poor shape. [Red=where ice should be]
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Western Hudson Bay polar bears continue their offshore migration eastward. It's very unusual that the eastern side of the Bay isn't frozen. The bears I track don't usually go all the way across but some do. The lack of ice is, however, a problem for bears over there.
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@Zoogai Polar bears have always used non-marine prey as far back as earliest explorers accounts. Inuit knowledge provides similar insights. "switching" is not the terminology I'd use, exploited & reported more often in association with increased time on land would be more accurate.
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