Satellites images might be able to replace aerial counts of polar bears in some places — if there are no clouds. But it seldom distinguishes cubs and can’t tell males from females, found a 2012 study of Foxe Basin bears that’s just been published.
Note: This is my 200th post since July 26, 2012!
Posted in Population
Tagged aerial survey, cubs, Foxe Basin, helicopter survey, polar bear, population estimates, Rowley Island, satellite images, sea ice, September ice minimum, Seth Stapleton, USGS
While researching the population status of Foxe Basin polar bears I came across an issue that seems to have garnered relatively little attention outside the polar bear community – Inuit objections to the handling of polar bears during mark-recapture surveys and the effect of this on polar bear research in Canada.
Foxe Basin is a large polar bear subpopulation region that encompasses the northern portion Hudson Bay into the area west of Baffin Island, see map below (courtesy IUCN Polar Bear Specialist Group).
Mark-recapture research methods routinely used by polar bear biologists became especially contentious in Foxe Basin during a population study initiated in 2007/2008, with Inuit residents voicing objections and biologists defending its practice. The following year, the mark-recapture effort was halted and an aerial survey took its place.
The aerial survey has been completed and a report on it was released in 2012 (Stapleton et al. 2012; see previous post for results) but we’ve heard very little about what happened to that mark-recapture study and why the Government of Nunavut pulled the plug on it. I plan to change that with the next couple of posts.
I’m not claiming to understand the nuances of the story because I’m only going by available documents. However, I think it’s important to shine some light on this issue since it has clearly changed the shape of polar bear research in Canada.
Posted in Life History, Population
Tagged aerial survey, Atkinson, Canada, Derocher, field work, Foxe Basin, Inuit, mark-recapture, non-invasive research, Nunavut, objections to mark-recapture, Peacock, polar bear handling, polar bear research, research methods, Stapleton, tainted meat, tranquilizer drugs, Zoletil
Figure 1. Polar bear subpopulation regions defined by the Polar Bear Specialist Group, Foxe Basin marked.
Foxe Basin is a large subpopulation region (Fig. 1), with a total area of 1.18 million square km (Vongraven and Peacock 2011). It comprises Northern Hudson Bay and western Hudson Strait, and the area between western Baffin Island and eastern Melville Peninsula, with a large island (Southampton Island) in the middle (Figs. 2 and 3).
Figure 1. Foxe Basin polar bears subpopulation region, courtesy IUCN PBSG
Posted in Life History, Population
Tagged aerial survey, body condition, fatty acid analysis, Foxe Basin, mark-recapture, Mitch Taylor, Nunavut, Obbard, Peacock, polar bear diet, Polar Bear Specialist Group, population status, Stapleton, starving polar bears, Thiemann
UPDATE February 11, 2014. A reader (Kevin, at “Afton’s Waterfowl List”) has pointed out an error in Fig. 3, where I inadvertently labeled the bars on the upper graph as ending in 2011 instead of 2012 (the Pembroke graph ends at 2011. sigh..). I have corrected the figure and the text that refers to it, but do not believe it affects the overall conclusion. See for yourself. Thanks Kevin — and Alan for getting in touch!
Another round of press release inspired news stories emerged last week insisting that polar bear predation on ground-nesting birds during the summer ice-free period is evidence that they are nutritionally stressed by global warming.
A few weeks ago it was snow goose eggs in Western Hudson Bay – this time it’s thick-billed murre (Uria lomvia) and common eider (Somateria mollissima) eggs in Foxe Basin and Hudson Strait (e.g. see the story at Canada’s National Post and a short summary provided by Science [and it’s not even their paper!]). The source of the media attention this time is a newly-published paper by Samuel Iverson and colleagues (Iverson et al. 2014).
Figure 1. From Iverson et al. 2014 (their Fig.1), “map of the study area.” Most of the study sites are within the Foxe Basin polar bear subpopulation region (see Fig. 2 below), although the Ungava Peninsula (E), Ungava Bay (F) and Frobisher Bay (C) sites are in the Davis Strait subpopulation.
Polar bears have always preyed on ground-nesting sea bird and goose eggs while onshore (see Kelsey Eliasson’s take on the situation around Churchill, at his PolarBearAlley blog). The issue in this case is whether the increase in predation can be unquestionably blamed on reduced sea ice cover and nutritionally-stressed bears – that is, predation increases that correlate with year-to-year sea ice changes and bears in poor condition found consuming bird eggs.
As I did for the “polar bears eat more caribou and snow geese than they used to” press release, I refused to take the PR or the news stories at face value and went to the published paper and its supplemental data (it’s open access, see it for yourself here).
What I see in this paper is a spurious sea ice correlation and no data on the condition of the few bears observed consuming eggs. There is also no mention of the fact that polar bear numbers have increased in part of the study area (Davis Strait) or that bears in Foxe Basin and southern Davis Strait have been found to be in very good condition and reproducing well (Rode et al. 2014; Peacock et al. 2013). See my analysis below and judge for yourself.
Posted in Conservation Status, Life History, Sea ice habitat
Tagged alternative prey, Davis Strait, Foxe Basin, Gilchrist, Hudson Strait, Labrador, nutritional stress, Peacock, polar bear, Rode, Samuel Iverson, sea bird eggs, sea ice decline, starving polar bears, terrestrial foods
I keep coming across mentions of a grandiose plan for future polar bear research and conservation called the “Circumpolar Monitoring Framework for Polar Bears.”
This “framework” plan was referred to extensively at the recent International Polar Bear Forum (aka the “Meeting of the Parties” that signed the 1973 conservation treaty) held in Moscow, December 3-6, 2013 (see posts about the meeting here, here, and here). In fact, government representatives of all Arctic nations present at that meeting agreed in principle to support the proposed plan.
No media reports that I’ve come across after the Moscow polar bear meeting explained what the “monitoring framework” involved, so I’ve composed a brief summary and commentary, aided by some images from Dag Vongraven’s presentation in Moscow (Vongraven 2013; pdf here).
In short, Arctic government representatives at the Moscow forum agreed that all future polar bear research should be constrained by the premise that increases in global temperatures over the next century will occur exactly as predicted by climate models and will negatively affect polar bears precisely as predicted by models devised by polar bear biologists. Under the plan, subpopulations that are already showing predicted effects of global warming will get the bulk of research funds, while regions that are paradoxically not responding as predicted will get much less money for research and survey efforts.
This strategy proposes a coordinated research plan that is blatantly agenda-driven: implementing it would seriously compromise the usefulness of all research results generated for decades to come. I don’t think it’s anything close to being a scientifically valid plan, but decide for yourself.
Figure 1. Vongraven 2013, Title slide.
Posted in Conservation Status, Sea ice habitat
Tagged Amstrup, Chukchi Sea, Circumpolar monitoring framework, contradictory evidence, Dag Vongraven, Davis Strait, Foxe Basin, Harris, PBSG, Polar Bear Specialist Group, population estimates, sea ice ecoregions, Southern Hudson Bay, Ursus journal, Vladimir Kattsov, western hudson bay
What did I tell you, back in mid-September?
Have a look at all the polar bear habit, ten days shy of the end of November!
Figure 1. MASIE sea ice extent for November 18, 2013 (using US National Ice Center data). You have to look closely but there is indeed ice forming around Svalbard (just above the tip of Greenland) and in James Bay (southern Hudson Bay). Click to enlarge. High resolution map here.
Figure 2. Canadian Ice Service map. Ice developing rapidly in northern Hudson Bay, Foxe Basin and Davis Strait (between southern Greenland and Baffin Island), with ice also forming along the shore in James Bay (the southern-most region where polar bears are onshore at the moment). Click to enlarge.
Posted in Sea ice habitat
Tagged Canadian Ice Service, Davis Strait, Foxe Basin, James Bay, polar bear habit, polar bears, sea ice extent, sea ice maps, Southern Hudson Bay, Svalbard, western hudson bay
The myth that northern Hudson Bay communities are having problems with polar bears this year because freeze-up is later than usual just won’t go away.
I discussed the well publicized craziness in Churchill last week (here and here), but there’s more. Polar bears are already leaving the shore of Northern Hudson Bay as the ice rapidly forms but I saw a story yesterday (dated late last week) that quoted a local official in Repulse Bay blaming their polar bear problems on late freeze-up.
I’ve written before about the peer-reviewed paper by polar bear researchers Seth Cherry and colleagues published earlier this year on breakup and freeze-up dates between 1991 and 2009. But perhaps the freeze-up data needs more emphasis. I’ve copied that graph again below, with notes, and added some ice maps. See for yourself.
Bottom line: A “late freeze-up” for northwestern Hudson Bay occurs when ice formation is delayed until early December or beyond. Freeze-up was nowhere near “late” this year, nor was the ice “slow to freeze.” It wasn’t last year either.
Posted in Life History, Polar bear attacks, Sea ice habitat
Tagged Arviat, Canadian Ice Service, Foxe Basin, freeze-up, Hudson Bay, human-polar bear conflicts, migration, November ice extent, NSIDC, polar bear problems, polar bears, Repulse Bay
The polar bear subpopulation designated as Lancaster Sound lies at the eastern entrance to the Northwest Passage in the Canadian High Arctic (Fig.1). We rarely hear about it but this region has one of the largest polar bear populations anywhere in the Arctic – only the Barents Sea and Foxe Basin have higher estimated population sizes.
Figure 1. Polar bear subpopulations with Lancaster Sound marked. Map courtesy IUCN Polar Bear Specialist Group, additional labels added.
Lancaster Sound includes the communities of Arctic Bay on northwestern Baffin Island and Resolute Bay on Cornwallis Island. Devon Island, which lies on the northern boundary, has no permanent communities, although two research stations are present (see here and here). A more detailed map showing the exact boundaries is available in Vongraven and Peacock (2011).
The eastern portion of Lancaster Sound is generally clear of ice by late summer (hence the Northwest Passage) but the western third of the region not only retains pack ice later in the season but some multiyear ice remains throughout the year.
The proximity of Lancaster Sound to Baffin Bay and the eastern Northwest Passage (Fig.2) undoubtedly exposed polar bears there to hunting by European whalers during the 1800s and early 1900s (see previous post here, especially Fig. 5), from which the population appears to have recovered.
On the other hand, the proximity of Lancaster Sound to oil and gas reserves further north in the High Arctic generated much-needed funds for polar bear biologists in the mid-to-late 1970s to collect essential baseline data for the entire region (Schweinsburg et al. 1982; Stirling et al. 1979, 1984; Stirling and Latour 1978).
Figure 2. The main Northwest Passage route starts at Lancaster Sound and runs east through Parry Channel because these waterways routinely clear of ice in late summer. The approximate boundary of the Lancaster Sound polar bear subpopulation is marked in yellow; POW is Prince of Wales Island. Map from Wikipedia, labels added. Click to enlarge.
Posted in Conservation Status, Population, Sea ice habitat
Tagged Arctic Bay, baffin bay, Barents Sea, Chukchi Sea, Davis Strait, Devon Island, fossil fuels, Foxe Basin, funding from oil companies, Lancaster Sound, male-biased hunting, natural gas, Northwest Passage, over-harvest, PBSG, Polar Bear Specialist Group, population estimate, Resolute Bay, Rode, Schweinsburg, sea ice decline, Stirling, Taylor