Tag Archives: summer

Brace yourself: more starving polar bear news stories in the pipeline from Svalbard

A few polar bears have become stranded on small islands north of Svalbard since the local sea ice retreated — of which the bear that mauled a cruise ship guard last month was but one — and if return of the ice is as late as last year, those handful of bears are likely doomed to die of starvation. This is not due to climate change but rather bad judgment on the part of these few bears. They were not forced ashore: if they’d stayed on the ice like the rest of the population, they’d have likely been just fine.

Daily Mail stranded bear headline_3 Aug 2018 all

Similar to the bear in northwestern Hudson Bay that fatally mauled a young father in early July, these bears were likely lured ashore by the prospect of masses of bird eggs present on island rookeries. But they overstayed their window of opportunity and the ice retreated without them.

Fledgling birds and bird eggs are not replacements for seals in a bear’s diet but when the season of easy seal kills winds down, as it does in late spring, easy-picking sea bird eggs may be enticing enough to lure a few bears ashore when they’d be better off on the ice.

That is not the fault of climate change.

Unlike bears in Hudson Bay and many other regions — including the Lancaster Sound area of Canada where the National Geographic “starving” bear was filmed last summer — these bears were not forced ashore by retreating ice: they chose to do so.
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Sea ice is critical habitat for polar bears from late fall through late spring only

Sea ice is said to be “an essential habitat for polar bears” but that’s an overly simplistic advocacy meme as ridiculous as the “no sea ice, no polar bears” message with which the public is constantly bombarded. Polar bears require sea ice from late fall to late spring only: from early summer to mid-fall, sea ice is optional. Historical evidence of polar bears that spent 5 months on land during the summer of 1874 proves an extended stay ashore is a natural response of polar bears to natural summer ice retreat, not a consequence of recent human-caused global warming. Sea ice is a seasonal requirement for polar bears: it’s not necessary year round.

polarbears-arcticnatlwildliferefuge-suzannemiller-usfws_labeled_sm

[This PBI newsletter from 2011 repeats this meme and Andrew Derocher’s recent tweet conveys a similar message (“Sea ice loss = habitat loss for polar bears”)]

As long as sea ice is available from late fall through late spring (December to early June) and accompanied by abundant seal prey (sometimes it isn’t, see Derocher and Stirling 1995; Stirling 2002; Stirling et al. 1981, 1982, 1984), polar bears can survive a complete or nearly complete fast from June to late November (and pregnant females from June to early April the following year). That’s the beauty of their Arctic adaptation: fat deposited in early spring allows polar bears to survive an extraordinary fast whether they spend the time on land or sea ice.

Young and very old bears, as well as sick and injured ones, are the exception: these bears often come ashore in poor condition and end up dying of starvation — as a much-publicized bear on Baffin Island who likely had a form of cancer did last summer (Crockford 2018). Competition with bigger, stronger bears means these bears can’t keep what they are able to kill and they are most often the bears who cause problems. Starvation is the leading natural cause of death for polar bears because if they cannot put on the fat they need in spring, they will not survive the low food months of summer and winter, whether they are on land or out on the sea ice (Amstrup 2003). Continue reading

Just look at what the ‘global heat wave’ is doing to polar bear sea ice habitat!

According to the Guardian (9 July 2018), there is a “global heat wave” going on right now.

In Siberia, the heat is supposedly “completely unprecedented” and will surely (we are told) impact Arctic sea ice — the habitat of the iconic polar bear.  Yet a comparison of previous years shows little to no impact on sea ice: there is more ice present than there was in 2007.

Polar Bear Breaks Ice

Said The Guardian:

“But though we cannot say definitively that the current heatwave is caused by carbon emissions, it fits the pattern of long-term changes that we call climate. It is part of a global phenomenon, even if not the most important part. The really significant change is happening in eastern Siberia at the moment, where a completely unprecedented heatwave is warming that Arctic coastline, with consequences that are unpredictable in detail but surely bad on a large scale.” [my bold]

The heat — which some folks admit they not only expect during this season called summer but anticipate with joy — has been around since late June, with several locales outside Siberia affected, including southern Ontario, Quebec, Los Angeles CA, Britan, many locations in the eastern USA, Europe.

With so many locations across the Northern Hemisphere experiencing very hot weather over the last few weeks (maybe record-breaking, maybe not), let’s take a look at what all that heat is doing to Arctic sea ice compared to previous years.
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Spring feeding for polar bears is over – sea ice levels are now largely irrelevant

Polar bears in virtually all regions will now have finished their intensive spring feeding, which means sea ice levels are no longer an issue. A few additional seals won’t make much difference to a bear’s condition at this point, except perhaps for young bears that haven’t had a chance to feed as heavily as necessary over the spring due to inexperience or competition.

Polar bear feeding by season simple_Nov 29 2015

The only seals available on the ice for polar bears to hunt in early July through October are predator-savvy adults and subadults. But since the condition of the sea ice makes escape so much easier for the seals to escape, most bears that continue to hunt are unsuccessful – and that’s been true since the 1970s. So much for the public hand-wringing over the loss of summer sea ice on behalf of polar bear survival!

Polar bears in most areas of the Arctic are at their fattest by late June. They are well prepared to go without food for a few months if necessary – a summer fast is normal for polar bears, even for those that spend their time on the sea ice.

Putting on hundreds of pounds of fat in the spring to last through periods of food scarcity later in the year (at the height of summer and over the winter) is the evolutionary adaptation that has allowed polar bears to live successfully in the Arctic.
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Amstrup & colleages can’t refute my critique of their 2007 polar bear survival model, Part 2

Polar bear specialists Andrew Derocher and Steven Amstrup recently spent inordinate energy trying to refute the opinion piece I’d written for the Financial Post in celebration of International Polar Bear Day last month, ignoring my fully referenced State of the Polar Bear Report for 2017 that was released the same day (Crockford 2018) and the scientific manuscript I’d posted last year at PeerJ Preprints (Crockford 2017).

polar_bear_USFWS_fat Chukchi Sea bear

Their responses use misdirection and strawman arguments to make points. Such an approach would not work with the scientific community in a public review of my paper at PeerJ, but it’s perfect spin for the self-proclaimed “fact-checking” organization called Climate Feedback. The result is a wildly ineffective rebuttal of my scientific conclusion that Amstrup’s 2007 polar bear survival model has failed miserably.

This is Part 2 of my expose, see Part 1 here.
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Fat healthy polar bear update: hundreds of not-starving bears attracted to dead whale

Are the hundreds of polar bears spending the summer on Wrangel Island in the Chukchi Sea starving and desperate for any scrap of food? Hardly! Photos taken by Russian tourists on a cruise ship (19 September 2017) show a huge number of already-fat, healthy bears converging on a dead bowhead whale washed up on a beach. Most of these bears would have been without food since at least early August, when the last sea ice disappeared around the island, and will return to the ice by November.

Wrangel Island bears on whale_29 Sept 2017 SUN

This is what The Sun reported (29 September), based on a Siberian Times story (my bold):

The extraordinary sight was witnessed by tourists on an Arctic cruise aboard the Finnish-built MV Akademik Shokalskiy.

A source at Wrangel Island Nature Reserve said: “There were at least 230 polar bears, including single males, single females, mothers with cubs and even two mothers with four cubs each.”

Experts called the sight of so many polar bears together “unique”.

The huge number could in fact amount to as much one per cent of the entire world’s population of the creatures.

Tourists initially thought the bears were a flock of sheep after viewing them from a distance, The Siberian Times reports.

But as the boat drew closer, the lucky holidaymakers realised what they were witnessing.

Fat cubs of the year are seen in the photo below, from the Siberian Times story:

Wrangel Island bears on whale_29 Sept 2017 Siberian TimesA self-proclaimed science-based news site (LiveScience, 29 September) that picked up the story of this unique event had the temerity to suggest the bears might have been “hungrier than usual” due to global warming.

It deliberately conflates predictions of future starving bears due to low sea ice levels with this observation of many obviously not-starving bears checking out an attractive food source (my bold):

“It’s unclear, however, whether climate change had made these particular bears hungrier than usual. The frequency of starving polar bears is expected to increase as the climate warms and sea ice declines — not just because of climate change directly, but because ice loss is taking away seals, their main food source, Steven Amstrup, chief scientist at Polar Bears International, a nonprofit research organization dedicated to studying polar bears, told Live Science in 2015.”

Except that there is no evidence that ice loss is “taking seals away” — certainly not in the Chukchi Sea. Chukchi Sea seals have been found to be doing better with less ice than they were when there was more ice in the 1980s.

More below, including the location of Wrangel Island and sea ice maps.

UPDATE 2 October 2017: Sea ice in the Chukchi Sea has been lower this summer than over the last few years but the polar bears spending the ice-free season on Wrangel Island are still in good to excellent condition:

r02_Chukchi_Sea_ts_4km at 2017 Oct 1

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Problem polar bears in Churchill at this date show 2017 less than 2016 and 2015

Comparing Churchill problem bear statistics over a few years provides some critical perspective: this year, the bears are causing much fewer problems.

This 2nd week in September is no exception, being the 9th week ashore in all cases: 2017 (4-10 September, where I think “total number of polar bear occurrence reports to date” should be 64, not 53, see week 7 report here), 2016 (5-11 September), 2015 (7-13 September), where there were about 1/2 the number of bears in “jail” this year compared to the last two years (i. e., 6 vs. 11 and 12) and slightly more than 1/2 the number of occurrence reports in 2017 than in 2016 and 2015 (64 vs. 107 and 99):

2017 week 9 Sept 4-11 may be typo

2016-sept-5-11_week-9.jpg

2015 Sept 7-13_at Sept 14