Tag Archives: conflicts

Abrupt summer sea ice decline has not affected polar bear numbers as predicted

Yes, Arctic sea ice has declined since satellite records began in 1979 but polar bears have adjusted well to this change, especially to the abrupt decline to low summer sea ice levels that have been the norm since 2007.

Global pb population size sea ice 2017 July PolarBearScience

Some polar bear subpopulations have indeed spent more time on land in summer than in previous decades but this had little negative impact on health or survival and while polar bear attacks on humans appear to have increased in recent years (Wilder et al. 2017), the reasons for this are not clear: reduced summer sea ice is almost certainly not the causal factor (see previous post here).

Ultimately, there is little reason to accept as plausible the computer models (e.g. Atwood et al. 2016; Regehr et al. 2016) that suggest polar bear numbers will decline by 30% or more within a few decades: even the IUCN Red List assessment (Wiig et al. 2015) determined the probability of that happening was only 70%.

Arctic sea ice has never been a stable living platform (Crockford 2015): it shifts from season to season, year to year, and millennia to millennia. Without the ability to adapt to changing conditions, Arctic species like polar bears and their prey species (seals, walrus, beluga, narwhal) would not have survived the unimaginably extreme changes in ice extent and thickness that have occurred over the last 30,000 years, let alone the extremes of sea ice they endured in the last 200,000 years or so.

Some biologists continue to hawk doomsday scenarios for polar bears due to summer sea ice loss but the truth is that their previous predictions based on sea ice declines failed so miserably (e.g. Amstrup et al. 2007) that it’s impossible to take the new ones seriously — especially since the basic assumptions that caused the first predictions to fail have not been corrected, as I’ve stated in print (Crockford 2017:27):

In summary, recent research has shown that most bears are capable of surviving a summer fast of five months or so as long as they have fed sufficiently from late winter through spring, which appears to have taken place since 2007 despite marked declines in summer sea ice extent.

The assumption that summer sea ice is critical feeding habitat for polar bears is not supported.

Recent research shows that changes in summer ice extent generally matter much less than assumed in predictive polar bear survival models of the early 2000s as well as in recent models devised to replace them (Amstrup et al. 2010; Atwood et al. 2016a; Regehr et al. 2015; Regeher et al. 2016; Wiig et al. 2015), while variations in spring ice conditions matter more.

As a consequence, the evidence to date suggests that even if an ‘ice-free’ summer occurs sometime in the future ­ defined as sea ice extent of 1 million km2 or less (Jahn et al. 2016) ­ it is unlikely to have a devastating impact on polar bears or their prey. [my bold]

The abrupt drop in summer sea ice that occurred in 2007 was not predicted by experts to occur until mid-century yet the predicted decimation of polar bears worldwide expected under those conditions (a loss of 2/3 of the global total, to only about 6660-8325 bears) not only did not happen, it did not come even close to happening (Crockford 2017; see also my recent books, Polar Bear Facts & Myths, and Polar Bears: Outstanding Survivors of Climate Change, sidebar).

Instead, the global population grew from about 22,550 bears in 2005 to about 28,500 bears in 2015. And while this might not be a statistically significant increase (due to the very wide margins of error for polar bear estimates), it is absolutely not a decline.

The present reality is that low summer sea ice cover since 2007 has not caused polar bear numbers to decline and therefore, polar bears are not a species in trouble. This suggests that even if the Arctic should become briefly ice-free in summer in the future, polar bears are likely to be only minimally affected and not become threatened with extinction. Polar bears are outstanding survivors of climate change: recent research and their evolutionary history confirm this to be true.

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Polar bear attacks are extremely rare says new study — but the data are incomplete

I did considerable research on polar bear attacks for my thriller of a novel EATEN — which many readers are finding a welcome change from the numbers-and-statistics approach of science — and I have to say that a recently published scientific summary of this phenomenon (1880-2014) authored by biologist James Wilder and colleagues left me speechless (Wilder et al. 2017).

Isbjørn

with permission, see EATEN cover.

By attempting to generate information that could be assessed with statistical methods, the authors ended up with data that is so skewed and incomplete that it fails to provide a plausible assessment of the risk to humans of attacks by polar bears. In my opinion, acknowledging that well-reported attacks on Europeans (or recorded by them) make up the bulk of the data used in the paper does not adequately address the weakness of the authors’ conclusions that attacks by polar bears are “extremely rare.”

The paper also focuses much attention on the potential for increases in polar bear attacks on humans due to sea ice loss (blamed on global warming) but ignores totally the increased risk stemming from the larger proportion of adult males that now exist in protected populations. Adult males frequently steal the kills of younger bears and in recovering (i.e. growing) populations, relatively more adult males potentially generate more young males that are nutritionally stressed and at risk of attacking humans (see discussion below).

Finally, no supplementary data is provided to show which records of attacks were included in the study, and no information is provided about how to access the database. How is that possible in this day and age?

Much is made in the paper of the negative effect of polar bear attacks on conservation objectives and the perceived increase in attacks associated with recent sea ice loss. These points were picked up by activist organization Polar Bears International (“Save Our Sea Ice!“) in a press release issued yesterday (11 July, pdf here). This has already generated the desired media attention (here and here, likely more to follow, like this) which is predictably focused on predictions of more polar bear attacks on humans due to global warming.

I have a feeling Inuit and other native inhabitants of the Arctic will not be impressed.

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In case you missed it…writer James Delingpole puts my novel in context

From Saturday 8 October, English journalist, author and broadcaster James Delingpole (via his Breitbart column) writes about polar bears:

delingpole-8-oct-2016-headline

The Truth About Polar Bears: They’re a Dangerous, Out of Control Pest…

Crockford is the author of a Jaws-style thriller on ravenous polar bears killing humans called Eaten. At least one polar scientist who has read it considers its “science-based scenario” to be frighteningly plausible.

In field-level polar bear management circles, people don’t talk about the kind of scenario that forms the premise of this novel as an “if”. Instead, they describe it as a “when” and they are not looking forward to it.

Eek.

Eek is right! The book has been nightmare-inducing for many readers. Put EATEN on your Christmas shopping list (all purchase options here). It makes a great gift and supports the work I do here. Colleagues have said their young adult children really enjoyed it.

[I’m reminded of Christmas since we had turkey for Canadian Thanksgiving this weekend – a fabulous gathering of all the local family at my place, including the two (!!) grandbabies, both of whom are now walking. I’ll be sending Nico to Churchill before you know it]

[And FYI, I’ve updated the Svalbard “problem no one is talking about” post with statistics by year (1974-2015) for polar bears killed to protect life and property]

Polar bear onshore in Tuktoyaktuk got so close to kids they heard it breathing

A report from the CBC this morning (with video) of a large polar bear wandering about the village of Tuktoyaktuk on the (Canadian) shore of the Eastern Beaufort Sea on Thursday (29 September) that got very close to a group of children playing outside. Fortunately, no one was hurt.

tuk-polar-bear-sighting-sept-29_cbc-oct-1-2016-headline

That this was a rare event is evident in the awe and excitement in the voices of the residents as someone recorded the movements of the bear through town (picture quality is not the best, but clear enough).

As I’ve said before, with more bears we can expect more interactions with people and more sightings like this that haven’t happened in decades. Map and quotes below.
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Polar bears onshore in winter – will more bears mean more deadly attacks?

Incidents of polar bears causing problems onshore this winter (January & February) – including one that killed a horse in Greenland and another that threatened a resident in western Hudson Bay (only weeks after several incidents in southern Labrador) may be the tip of a very scary iceberg. I’ve taken a look at what records exist of this phenomenon, which in the past often involved deadly attacks. The large number of reports this winter appears to be a real increase, which is a rather terrifying prospect indeed.

Doug Clark photo polar bears onshore in Feb 2013 Wapusk NP

In winter, all polar bears except females in dens nursing newborn cubs are presumed by biologists to be on the sea ice hunting but it turns out that is not quite true. Although relatively rare over the last twenty years or so, it appears that in some areas, bears are now coming ashore in winter.

The photo above shows a polar bear photographed by a remote camera installed at Broad River Camp, Wapusk National Park, western Hudson Bay on 7 February 2013. It was visible to the camera for 40 minutes but apparently caused no trouble (camera installed and maintained by associate professor Doug Clark from the University of Saskatchewan and colleagues).

Given the fact that there are now many more polar bears than there were in the 1970s as well as more people living in many coastal Arctic communities, problems with bears in winter are likely to increase, as this winter’s events show. More bears out on the ice in winter (January-March) will almost certainly create more competition for the little bit of food that’s available (seals are hard to catch in winter), which means some bears might increasingly be looking for alternate sources of food onshore.

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