Let me excerpt the concluding paragraph:

The benefit of being in a Tundra Buggy is that a bear is close but not a threat...

Nowhere close to freeze up in Hudson Bay this year. It's far too warm. No sea ice anywhere. Things can change quickly but the Bay has to cool a lot before ice strong enough to support polar bears shows up. Watch the Bay live here: explore.org/livecams/pol...

Latest polar bear paper exploring their role in providing carrion to other vertebrate species. Polar bears provide approximately 7,600,000 kg/year of carrion biomass for scavengers across their range. nsojournals.onlinelibrary.wiley.com/doi/10.1002/... [open access]

Mom & cub on the shores of Hudson Bay on the polar bear cam (explore.org/livecams/pol...). Timing of sea ice freezing up is critical for cub survival. If mom runs out of stored energy, she stops nursing & cubs have little stored energy of their own as they are growing so fast. This is a weak link.

No alarm for Hudson Bay polar bears yet as there's time for things to cool but at these temperatures, the Bay will still be warming. Normal for this date is -3 C to -9 C. It's a bit cooler further north but not cold. 1 kg of body mass loss per day - how long can they wait?

Hudson Bay polar bears are waiting (& will be for quite a while with the current weather - it's well above normal temperatures there). For now, most bears will still have lots of stored energy but the skinniest will be seriously hoping for sea ice to form so they can start feeding again.

Not much sign of freeze up coming anytime soon in Hudson Bay. At these temperatures, the Bay will need to cool for a while. Now, it's all about the weather & colder is better for polar bears. You can watch the Bay (& sometimes polar bears) here: explore.org/livecams/pol...

#ClimateCrisis @aederocher.bsky.social

Hudson Bay polar bears are waiting for the ice to form. It's +18 C (64 F) right now in Churchill & way above normal so they'll be waiting for a while. Bears are now about 120 days on land & have lost about 120 kg (265 lb). Bears without enough energy risk dying: it's survival of the fattest.

Western Hudson Bay polar bears are staying put & saving their energy. It's cooking there today at 27 C (81 F). At these temperatures, the Bay will still be warming. Field crew out now monitoring the bears report them in good condition with good subadult recruitment. Bodes well for this year.

Western Hudson Bay polar bears are doing what they usually do during the ice-free period: nothing. Energy conservation is the priority. For moms with cubs, avoiding other bears is also important (infanticide risk). Now the bears wait for cold & sea ice to return.

Latest from @ualberta.bsky.social polar bear research & Environment & Climate Change Canada. "percent of solitary females that were pregnant declined significantly over time and between time periods from 85% in 1982–90 to 73% in 1991–2021." Open access: academic.oup.com/conphys/arti...

The extraordinary loss of August #Arctic sea ice thickness over the last four decades... Data available at psc.apl.uw.edu/research/pro.... More info at climatedataguide.ucar.edu/climate-data...

Great to see & on my reading list. The anti-science nonsense about polar bears by climate change deniers was intense. Fortunately, the "counterpoint" media looked for on climate change effects on polar bears has evaporated as the key sources was toppled. We may, however, be moving into a new era.

We are featuring select articles available in IBA’s peer-reviewed journal, URSUS. McGeachy et al. “Possible sexually selected infanticide by polar bears in western Hudson Bay”. Full post on our IG & FB pages! Full article: doi.org/10.2192/URSU... IBA Members get access to all URSUS articles.

Western Hudson Bay polar bears are well spread out from Ontario to Nunavut (including 1 well to the NE). More bears went south than "normal" but it was also reflected in spring captures with many bears having no prior history. Now they wait for freeze-up (29 C, 84 F) forecast so it's hot!

Dr. Andrew Derocher (URSUS Editor & IBA member) has spent decades studying polar bears in Western Hudson Bay. This study tracks polar bear movements, body condition, and sea ice ecology to support conservation planning. @aederocher.bsky.social #bearconservation #polarbears #arcticresearch

Welcome home (almost all). Western Hudson Bay polar bears are ashore. High variation in onshore dates this year: some early & some late. Increased variation in polar bear ecology with climate change is common. We have a new paper soon showing high variation in pregnancy rates.

It's very unusual to see polar bears still out on so little sea ice. This is a change in behaviour compared to the past when 30% ice cover meant heading for land. Perhaps the hunting is still good? Perhaps they need to fatten more? Maybe they found a few solid bits of ice?

Some Hudson Bay polar bears STILL out on the last bits of sea ice. It's an interesting change in behaviour to have the bears out on so little ice. There's a reason for it: seals. No chance of killing a seal on land but they can out on the ice. Must be naive seals that come near the last ice.

For those curious about Bear E4, it's an adult male caught near Cape Churchill in Manitoba this spring who was on northern Québec a few days ago but has now moved to Mansel Island, Nunavut. This fellow isn't scared of swimming.

With so little ice left in western Hudson Bay, a surprising number of polar bears still hanging on to the last bits. This behaviour contrasts to the past when 50% ice cover had the bears ashore within weeks. The bears know what they're doing (or trying to do) [in an evolutionary context].

One of the warmest spots in the #Arctic relative to average last month was across the Canadian Arctic Archipelago (>5°C above the 1981-2010 mean). We will have to wait and see later this summer how the Northwest Passage fares. Data from @copernicusecmwf.bsky.social ERA5 reanalysis.

Churchill is warm: for context, normal is max 17°C & min 7°C. Sea ice has disappeared in the west with the more typical pattern of southern remnant ice (current & wind driven). We'll update tracked polar bear locations soon but if any bears are still out in Hudson Bay, they're on tiny bits of ice.

It's amazing to see so many polar bears still out on the last bits of ice in Hudson Bay. Bear E4 made it to land on the northern tip of Québec. Staying out on so little sea ice is a big shift in behaviour from the past decades.

Hudson Bay polar bears are hanging on to the last bits of sea ice in 2025. In the past <30% ice & bears were heading ashore. It appears the bears are now somewhat more flexible in their behaviour & staying out longer. Perhaps by necessity as they were lean this spring?

Precious little ice left in Hudson Bay but some polar bears we're tracking are staying offshore. Based on their poor condition this spring, some bears may need another seal or two to survive the on land period. Satellite images can't see the small bits the bears are using.

Most Hudson Bay polar bears are hanging on to the last of the ice. Several have crossed over to land. Sea ice is where the bears would prefer to be. One bear way offshore will have to make a move soon for which way to go for land.

Hudson Bay polar bears are coming ashore. It’s an early break up. When I started studying the bears here in 1984, some stayed out on the ice until August. They use 1 kg of stored energy per day so the ice-free period is a key factor in their success. The bears on the ice will be trying for seals.

Most Hudson Bay polar bears are edging closer to shore. Last of the sea ice is looking more like a slushy than habitat to hunt from. Mid-June is early but how the bears do with the onland fast period will depend on 1. how fat they are, 2. when autumn freeze-up happens.

It's an early break up in western Hudson Bay this year with the first polar bear onshore. Based on the condition of the bears I saw in April, this could be a challenging year. Satellite image shows very broken ice now. More bears ashore soon.

See why we call it Arctic "amplification" 🫣 Graphic available at zacklabe.com/arctic-tempe...

One of my favourite papers of past decade because the pseudoscience & climate denier nonsense from pretend polar bear scientists pretty much vanished. The main misinformation website was mothballed as media lost interest in fake science. academic.oup.com/bioscience/a...

For western Hudson Bay, break-up is advancing rapidly. Some polar bears have crossed over to landfast ice. This is an early breakup. Consequences for the bears are unknown until fieldwork in August starts. In contrast to 2024, it's not looking good for the bears.

Hudson Bay sea ice vastly different from 2024 (r) when wind pushed ice west. This year, open water near shore. Polar bears are capable swimmers so 50 km of open water isn't a problem but it depends on the bear (e.g., age, condition). Cubs, however, are much more vulnerable. Bears likely ashore soon.

For more details on graduate opportunities in my lab see: rdinnager.github.io/dinnage_lab_...

Missing sea ice off Hudson Bay west coast this spring is very different from 2024 when ice stayed late in west. We'll see how break-up progresses but the longer the ice persists, the better it will be for polar bear body condition & cub survival.

Arctic sea ice is tracking below the 2012 record low minimum cover. While the effects of sea ice loss vary across the 20 populations of polar bears, all are being affected but by differing degrees. We've not crossed critical fasting duration thresholds but we're often close.

Latest polar bear research from @ualbertascience.bsky.social led by MSc student Camille Jodouin found that the bears don't reuse areas on the sea ice. They show high fidelity to terrestrial areas but the sea ice (& likely prey) vary between years so returning to past locations isn't common.

Hudson Bay sea ice is rapidly melting. We'll see what it means for polar bears that would continue fattening well into summer if the ice persists. I suspect a challenging ice-free season. Bears we sampled this spring were all 2 or 3 /5 in body condition. Lower than 2024.

Hudson Bay polar bears are close to summering areas & trying to hunt on the melting ice. Hunting conditions deteriorate as the amount of open water increases (seals aren't stupid & surface away from ice where the bears are). 2 bears way offshore may do better but it's risky - long distance swims.

Rapid melt in Hudson Bay this year. We'll see how polar bears do: they weren't in great shape when we were conducting research out on the ice in April.

Hudson Bay sea ice May 2024 vs 2025. Last year was great for polar bears in western Hudson Bay (ice loss was in the east). This year, the loss is in the west. Temperatures have cooled a bit so perhaps the ice will linger & help the bears to fatten. Heavy forest fire smoke over Churchill.

Temperatures in Churchill are WAY above normal today & tomorrow. The impacts on sea ice are clear with break-up advancing quickly. This isn't shaping up to be a good year for polar bears in Hudson Bay. That brown layer over Churchill? Smoke from forest fires.

Nick Paroshy defended his MSc thesis this week. Excellent defence! Congratulations! Insightful analysis about how polar bear subpopulations can be delineated. Summary: it's not simple. @ualbertascience.bsky.social

Great MSc defence from Nick Paroshy examining polar bear subpopulation delineation in the Beaufort Sea. Really solid defence with lots of interesting questions, discussion & debate.

Hudson Bay polar bears are staying close to their summering area centred in Wapusk National Park. They're liking gorging on bearded seal pups and juvenile ringed seals now (at least I hope so). Lot of melting ice & warm forecasts don't bode well for the bears.

Fantastic defence by Anna Jovtoulia. Interesting findings: we had predicted that caribou would be a common prey but it turns out that beaver were the big menu item. Congratulations Anna!

Rapid & early ice loss from NW Hudson Bay this spring is a concern for polar bears and more so given the very warm temperatures predicted for later this week (far above normal). 2024 was a good year for the bears, 2025 doesn't look like that so far.