Tag Archives: fall

Late fall polar bear habitat 2020 compared to some previous years

It’s time to look at sea ice habitat at 15 December (Julian Day 350), now that virtually all bears except pregnant females throughout the Arctic are either out on the sea ice attempting to hunt for seals or hunkered down against the darkness.

As is usual at this time of year, the Canadian Archipelago, the Beaufort, East Siberian and Laptev Seas are well covered in ice (see regions on map below). As for the rest, despite what one polar bear specialist has implied there is no evidence that a slower-than-usual fall freeze-up in the other peripheral seas of the Arctic negatively affects polar bear health or survival.

In fact, because of the attractiveness of the ice edge for seals in the fall, as I discussed last month, it’s possible that the longer the ice edge persists in fall, the more successful polar bears will be in hunting seals – except those above the Arctic Circle where lack of daylight from early November may cause polar bears to hunker down and rest rather than try to hunt through the darkness. But we’ll never know for sure, because bears have never been studied at this time of year – experts simply make assumptions about what happens (e.g. Stirling and Oritsland 1995).

Sea ice thickness also varies year to year throughout the season but does not matter much to polar bears, who hunt most successfully in first year ice less than 2m in thickness, which comprises all of the regions currently purple in the ice thickness chart below.

Hudson Bay

This year at mid-December, there was more ice than usual in central and southern Hudson Bay (below) and somewhat less than usual in the eastern portion.

However, the ice is forming so fast now that by 18 December there was hardly any open water remaing over Hudson Bay and the ice to the north was solidifying (below). Recall that a similar freeze-up pattern left a pod of a dozen or so killer whales stranded in mid-January 2013 and killed four others in 2016. Such ice-entrapment suggests that despite a ‘warming’ Arctic, freeze-up patterns would have to change very dramatically for Hudson Bay to be an attractive place for killer whales. A recent DFO report concluded:

Killer whale ice entrapments are almost always fatal and can wipe out entire family groups, with long-lasting demographic impacts. Ice entrapments could therefore slow Arctic killer whale range expansions, particularly in areas where killer whales that are unfamiliar with sea-ice patterns fail to exit prior to ice formation in winter.

Compare Hudson Bay weekly stage of development charts (below) for this year back to 2014, from the Canadian Ice Service archives. You’ll see that this year appears to have more extensive 1st year ice (light green, ca. 30-70 cm) than any other year (although last year had almost as much) and that 2016 was notable as being a very late freeze-up year:

Western Hudson Bay polar bears with collars or tags deployed by Andrew Derocher and his University of Alberta crew (below) are spread out over the ice of the bay (two on land are denning females), a number are on the thickest ice in the north but others are on thinner ice to the south and east:

Baffin Bay, foxe basin, and Davis Strait

Ice covereage in the Canadian Eastern Arctic at mid-December is about average this year, according to CIS charts – only a bit of red and pink indicating ‘below normal’ in the east (off of Greenland):

Pack ice has moved down from the north through Baffin Bay into Davis Strait (below) and will soon be off the coast of Labrador, which has somewhat less ice than usual this year at mid-December:

The ice off Labrador at this time is shorefast ice developing and thickening in place (below). As far as we know, few polar bears summer on the northern Labrador coast, so this late ice development is unlikely to affect local bears. However, pack ice will move down during January and February until it engulfs the area north of Newfoundland, bringing some polar bears with it.

Greenland and Barents Sea

Freeze-up in the Greenland Sea is progressing a bit faster than usual for the last five years (below), but not remarkably so:

Ice cover in the Barents Sea (below) has been slow so far but has been progressing faster over the last few weeks. There is now ice off the east coast of Novaya Zemlya, shorefast ice that should allow any bears summering there to hunt for seals just as Western Hudson Bay bears do during early freeze-up stages. Within the next few weeks, the Arctic pack ice will move south into the Kara Sea, allowing bears to move more freely.Ice off Svalbard has been much below normal (below), as it has been for years now, which is why virtually all Barents Sea pregnant females currently make maternity dens in Franz Josef Land or on the sea ice to the north. These alternative areas for safely giving birth is the primary reason that the much reduced sea ice around Svalbard in recent years has not impacted Barents Sea polar bear health or survival.

Kara Sea

Ice cover in the Kara Sea at 15 December (below) is lower compared to the last five years but it’s unclear how much effect this will have on local polar bears.

Animals that have opted to spend the ice-free season on Novaya Zemlya or on the Russian mainland will have had a long wait for ice, but those that spent the summer on the Severnya Zemlya archipelago to the east had access to sea ice before the end of November. There has been no word from Belushaya Guba on whether the polar bear problems they had because of poorly maintained garbage dumps in December 2018 that went on until February 2019 have recurred this year.

Despite what Andrew Derocher claims (below), there is no evidence that slightly less sea ice in the fall is detrimental to polar bear health or survival in the Kara Sea or elsewhere. It is possible that it might but no one has studied it, so to suggest that low sea ice cover is ‘trouble’ for polar bears at this time of year is very misleading.

Chukchi/Bering Sea

Sea ice cover over the Chukchi Sea is a bit lower than it has been over the last few years, about as low as it was in 2017 (below).

Chukchi Sea polar bears at 14 December (below) had abundant sea ice habitat.

In 2016, when Chukchi polar bears were counted for the first time, there was a similar amount of ice at this time of year (below):

References

Stirling, I. and Øritsland, N. A. 1995. Relationships between estimates of ringed seal (Phoca hispida) and polar bear (Ursus maritimus) populations in the Canadian Arctic. Canadian Journal of Fisheries and Aquatic Sciences 52: 2594 – 2612. http://www.nrcresearchpress.com/doi/abs/10.1139/f95-849#.VNep0y5v_gU

Shorefast ice formation and the fall feeding season for polar bears

What may seem like a silly question is actually fundamental to polar bear survival: in the fall, why do Western Hudson Bay bears correctly expect to find seals in the new ice that forms offshore? Why are seals attracted to that new ice – called ‘shorefast ice’ or ‘fast ice’ – when they would clearly be safer out in the open water where there is no ice and no bears?

As the picture below attests, polar bears can and do kill ringed seals in the new ice that forms off the coast of Western Hudson Bay even when it is but a narrow strip of thin ice – and so close to shore their successes can be caught on camera.

Three adult male polar bears share a seal kill on the newly-formed ice off Wapusk National Park, Western Hudson Bay. 5 November 2020. Buggy cam, Explore.org

A different bear was also filmed killing another seal on 31 October. And these are only the kills we know about along a very short stretch of coast – the killing is almost certainly going on up and down the entire coast, into James Bay (see below), where there is just as much ice but no cameras.

As far as I am aware, this seal killing by polar bears goes on in newly-formed shorefast ice everywhere across the Arctic in early fall, not just in Hudson Bay. Although the timing varies, virtually everywhere in the peripheral seas of the Arctic Ocean (Barents, Kara, Laptev, Chukchi, Beaufort, as well as Baffin Bay and Davis Strait), shorefast ice forms before the mobile ice pack expands to meet the ice developing from shore.

This shorefast ice formation in fall provides a predictable but short-lived source of prey for polar bears as they strive to regain some of the weight lost over the summer.

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‘Our Planet’ film crew is still lying about walrus cliff deaths: here’s how we know

Last week, I called “contrived nonsense” on the claim by David Attenborough and the production crew of Netflix’s ‘Our Planet’ that the walruses they showed falling to their deaths were victims of global warming. After unbelieveable media attention since then, newly-revealed details only solidify my assertion. Something stinks, and it’s not just the bad acting of director Sophie Lanfear in the Behind the Scenes trailer as she delivers her WWF-approved message: “This is the sad reality of climate change”.

walruses2-1024x683_USGS

Despite many statements to the press, the film crew have steadfastly refused to reveal precisely where and when they filmed the walrus deaths shown in this film in relation to the walrus deaths initiated by polar bears reported by The Siberian Times in the fall of 2017.

I can only conclude, therefore, that the two incidents are indeed essentially one and the same: that the filmmakers, probably alerted by resident WWF employees at Ryrkaipiy, moved in after polar bears caused hundreds of walrus to fall to their deaths. The crew then captured on film the last few falls over the cliff as the walrus herd moved away from the haulout.

The lie being told by Attenborough and the film crew is that 200-300 walruses fell during the time they were filming, while in fact they filmed only a few: polar bears were responsible for the majority of the carcasses shown on the beach below the cliff. This is, of course, in addition to the bigger lie that lack of sea ice is to blame for walrus herds being onshore in the first place.

See my point-by-point analysis below and make up your own mind.

UPDATE 21 April 2019: I had an opportunity last night to watch the original Netflix walrus episode and have some addition thoughts that I’ve added below. [see separate post here]

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Attenborough’s tragedy porn of walruses plunging to their deaths because of climate change is contrived nonsense

A recent Netflix ‘Our Planet’ program with David Attenborough delivering a disturbing message of doom about walruses falling off a cliff to their deaths because of climate change is contrived nonsense on par with the bogus National Geographic starving polar bear video of 2017.  The walruses shown in this Netflix film were almost certainly driven over the cliff by polar bears during a well-publicized incident in 2017, not because they were “confused by a combination of shrinking ice cover and their own poor eyesight“.

Walrus plunging cliff_The Sun headline 5 April 2019

Apologies for neglecting to add, h/t to Charles the Moderator from WUWT!

UPDATE 8 April 2019: Falling off cliffs is not a new phenomenon. Here is video of US Fish and Wildlife officials in 1994 trying to explain a situation where walruses are falling even without the impetus from polar bears, at Cape Pierce in the southern Bering Sea (a haulout for adult males during the ice-free season). Explanation? Overcrowding (too many walruses)! h/t to Mark Sullivan.

Also, see this 8 April 2019 piece from The Atlantic that confirms the ‘Our Planet’ footage was filmed in 2017, and that “the sequence includes footage from two separate beaches—one with the 100,000-strong congregation and one with the falls.”

UPDATE 9 April 2019: For the details on why the two events described below (the one filmed by Attenborough’s ‘Our Planet’ crew and the event reported by the Siberian Times in 2017) are almost certainly one and the same, see Andrew Montford’s post at The Spectator. The Global Warming Policy Foundation has issued a press release.

UPDATE 14 April 2019: New details show that the film crew are still lying about the walrus death event in the Netflix ‘Our Planet’ episode, summarized by me here.

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Fall polar bear habitat update: 3 mkm2 Arctic sea ice increase in the last two weeks

What a difference two weeks make! When the seasonal minimum Arctic sea ice extent occurs in September, polar bear doom-mongers always forget to tell you that within two months, sea ice will return to virtually all regions where polar bears have spent the summer on land, including Hudson Bay. Just as it did in 2007, when polar bears did not die by the thousands due to lack of fall sea ice, polar bear habitat is reforming.

Polar bear tests thin ice_Laidre_UW_no copyright_taken22August2015_sm

This year, the seasonal minimum came on 23 September. Despite the fact that the US National Snow and Ice Data Center proclaimed that “unusual warmth” in the Arctic continued during October, over the last two weeks sea ice expanded from 6 mkm2 to 9 mkm2. At the current rate of ice growth documented by sea ice charts (see below), Arctic sea ice will be wide-spread by 23 November.

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No correlation between freeze-up dates for Hudson Bay & total Arctic ice cover

Guess which year between 2006 and 2016 had the latest start to freeze-up on Hudson Bay, given that 2012 had the lowest September average and 2007 and 2016 tied for second-lowest (see graph below, from NSIDC), and that sea ice in the Arctic right now is the lowest it’s been for this date since 1979?

sea-ice-sept-averages-graph-only-marked-for-2006-up

If you guessed anything other than 2010, you guessed wrong – in addition, 2006 (not 2016) was second latest.

There is no correlation between Arctic sea ice coverage and freeze-up dates for Western Hudson Bay.

Yet, Polar Bears International (“Save Our Sea Ice”) –  who were surely in and around Churchill in 2010 and 2006 watching polar bears – just posted an alarming statement about local conditions, implying that slow freeze-up of Hudson Bay this year is a reflection of the fact that “sea ice is at a record low across the Arctic.”

They also claim that “…the weather is the warmest we’ve ever seen at this time of year.” That may be true, but if so, it is also meaningless with respect to the progress of freeze-up.

Does no one at PBI remember the very late freeze-up of 2010 or 2006? Odd, that.

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Beaufort Sea polar bear habitat highest since 2008 at this date

Good news for Southern Beaufort polar bears! Sea ice converging on the north shore of Alaska earlier than any year since 2011 at least, according to NSIDCs regional ice plots (below).

r01_Beaufort_Sea_ts_4km

But wait, their Masie ice maps show it’s actually the earliest since 2008 (although the ice movement onshore was also earlier than 2006 and 2007, see below). And it’s still a full week before the end of October, the first month of Arctic fall (October-December). Lot’s of seal hunting habitat.

This emphasizes the fact that the primary problem faced by Southern Beaufort sea polar bears is not scarce summer ice but by thick sea ice conditions in the spring. Bears photographed near Kaktovik this year were in excellent condition (see here and here, taken by Kelsey Eliasson, Polar Bear Alley). If folks have been seeing starving bears, they haven’t said anything that I’ve been able to find.

Ice maps below.
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Many polar bears cubs seen in Svalbard this year, says Norwegian biologist

Good news from Norway: polar bears around Svalbard are in excellent condition this spring and many females with new cubs have been spotted. This is a marked turn around from conditions just last year.

 Roy Mangersnes / Wildphoto


Roy Mangersnes / Wildphoto

According to a Norwegian news outlet yesterday, Jon Aars (Fig. 1, below), from the Norwegian Polar Institute, confirms that this has been an excellent year for polar bear cubs around Svalbard because there has been abundant sea ice near denning areas on the east coast.

Figure 1. Biologist Jon Aars with a Svalbard cub.

Figure 1. Biologist Jon Aars with a Svalbard cub.

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Polar bears out on the sea ice eat few seals in summer and early fall

We hear endlessly about the polar bears ‘forced’ to go without food for months because of receding summer sea ice — what about all the bears that stay out on the ice over the summer? Presumably, those bears keep hunting for seals – but how many do they actually catch?

Polar Bear Breaks Ice

[Update 9 February 2015: Just to be clear, this post is based on the facts available in the peer reviewed literature — if you think I have missed something, let me know via the “Contact us” page above]
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