This year is a different story completely. It’s only early January and already there is abundant ice along the west coast of Novaya Zemlya; ice in the Barents Sea in general is well up over recent averages and the pack is already converging on Bear Island (Bjørnøya) to the south of the Svalbard archipelago. Ice this far south often brings polar bear visitors to the weather station there but that doesn’t usually happen until March or April.
You’ll find references in previous posts linked here.
Posted onDecember 1, 2021|Comments Off on Higher than average Svalbard sea ice extent in November 2021 has implications for birth of cubs
Early last November, sea ice around Svalbard was the lowest it had been since 1967 and pregnant females were simply unable to den on the eastern islands of the archipelago and instead had to make their dens and give birth in the pack ice or the Franz Josef Land archipelago further east, as they have done before. However, the ice is back this fall with a vengeance: even Hopen Island in the south of region was surrounded by ice well before the end of the month but whether it will attract a few pregnant females remains to be seen.
Posted onOctober 26, 2021|Comments Off on Caught on film: polar bear stalks, kills and eats a Svalbard reindeer but climate change is hardly to blame
The possibility that a polar bear somewhere in the Arctic might occassionally be successful at stalking and killing a reindeer (aka caribou) shouldn’t surprise anyone, let alone a biologist on Svalbard. But having video footage of the event makes it immediately newsworthy, especially when the researchers vaguely suggest that global warming might be to blame.
The title of the scientific paper that has generated the latest polar bear hype is called ‘Yes, they can: polar bears Ursus maritimus successfully hunt Svalbard reindeer Rangifer tarandus platyrhynchus’ (Stempnlewicz et al. 2021).
Would any serious scientist really think they couldn’t?
Posted onSeptember 8, 2021|Comments Off on Svalbard polar bear paper falsely assumes that loss of genetic diversity has negative consequences
A new paper published today deals with an animal conservation issue I’ve addressed twice before: the theoretical assumption that loss of genetic diversity must be detrimental to species survival despite there being little evidence that this has been the case in real life. For this new study, the authors carried out some complicated measuring of genetic diversity loss and inbreeding amongst and between Svalbard region polar bear populations between 1995 and 2016 (see map below), and then modelled what this could lead to in 100 generations (1210 years), with the over-anxious hand-wringing we’ve all come to expect from such prophesies. As far as I can see, it’s all meaningless number-crunching without relevance to the real world of polar bears.
To support their claim of harm from loss of genetic diversity, the authors of this paper (Maduna et al. 2021) cite four theoretical papers that assume as fact that loss of genetic diversity is harmful but not the evidence to back up the claim. They apparently never bothered to look at species that have actually suffered dramatic loss of genetic diversity. Northern elephant seals, for example, reduced to 20-30 animals more than 100 years ago, have rebounded to a population of about 170,000 with extremely low genetic diversity but no apparent health or survival repercussions. Similar genetic bottlenecks and recoveries have been documented in Guadalupe fur seals, San Nicolas Island foxes, mouflon sheep, and North Atlantic right whales (among others), which I discussed in detail here (with references). I discussed the issue again in regards to a similar polar bear ‘genetic diversity’ paper in 2016.
Conspicuous by its absence in this new publication is a citation of the recent paper that revealed the body condition of female Svalbard polar bears had increasedsignificantlybetween 2004 and 2017 despite a pronounced decline in summer and winter sea ice extent (Lippold et al. 2019: 988). Nor did the paper cite data collected by the Norwegian Polar Institute that show the body condition of adult males in Svalbard has not changed since 1993 or that population numbers have not declined. Instead, the authors mention only that reduced numbers of pregnant females have reached traditional denning areas due to lack of ice and that bears have spent less time feeding at glacier fronts than they used to do (Maduna et al. 2021: 2), as if the only polar bear data available in relation to sea ice decline was negative.
Population bottlenecks during the Last Glacial Maximum when suitable habitat was scarce and another in the late 1800s/early 1900s due to wanton overhunting left polar bears with remarkably low genetic diversity but no apparent ill-effects to their overall heath. Oddly, this recent work by Maduna and colleagues assumes without evidence that a bit less genetic diversity could be devastating to Svalbard bears more than 1000 years from now. While the media expectedly promote this as scary new evidence of what climate change has wrought (here and here), I am not impressed.
This is conservation biology done WWF-style: loss of genetic diversity sounds bad to people who don’t know better, but real-world evidence shows it isn’t.
Lippold, A., Bourgeon, S., Aars, J., Andersen, M., Polder, A., Lyche, J.L., Bytingsvik, J., Jenssen, B.M., Derocher, A.E., Welker, J.M. and Routti, H. 2019. Temporal trends of persistent organic pollutants in Barents Sea polar bears (Ursus maritimus) in relation to changes in feeding habits and body condition. Environmental Science and Technology 53(2):984-995. https://pubs.acs.org/doi/10.1021/acs.est.8b05416
Maduna, S. N., Aars, J., Fløystad, I., Klütsch, C. F. C., Zeyl Fiskebeck, E. M. L., Wiig, Ø. et al. 2021. Sea ice reduction drives genetic differentiation among Barents Sea polar bears. Proceedings of the Royals Society B 288 (1958): 20211741. https://doi.org/10.1098/rspb.2021.1741 OPEN ACCESS
Comments Off on Svalbard polar bear paper falsely assumes that loss of genetic diversity has negative consequences
Posted onAugust 20, 2021|Comments Off on Polar bear habitat update at mid-August
Oddly, after light winter ice coverage on Canada’s east coast and a slightly earlier sea ice breakup on Hudson Bay, the Arctic melt season has stalled. That’s not my opinion but the observation of the sea ice experts at the National Snow and Ice Data Center (NSIDC):
Sea ice loss during the first half of August stalled, though ice in the Beaufort Sea is finally starting to weaken. The Northern Sea Route appears closed off in 2021, despite being open each summer since 2008.
Overall, ice coverage is well above what it was in 2012 (the lowest September extent since 1979) and many years since:
Posted onJuly 3, 2021|Comments Off on Constant dire predictions have been an attempt to counter effective criticism of polar bears as AGW icon says outgoing PGSG chair
In an unexpected statement, Dag Vongraven (the out-going Chairman of the Polar Bear Specialist Group) suggests that much of the incessant dire warnings of doom about the future of polar bears from PBSG members has been a counter-measure to offset the effective efforts by myself and others to expose the flawed rhetoric this group promotes.
It is important to realize that this range [i.e. their polar bear population estimate] never has been an estimate of total abundance in a scientific sense, but simply a qualified guess given to satisfy public demand.
Posted onJuly 1, 2021|Comments Off on Barents Sea polar bears thriving despite huge summer ice loss: spring research results are in
After being locked out last year, fieldwork monitoring polar bears in the Svalbard region of the Barents Sea resumed this spring. The results show that despite having to deal with the most extreme loss of summer sea ice in the entire Arctic, polar bears in this region continue to thrive. These facts show no hint of that impending catastrophic decline in population size we keep hearing is just around the corner. No tipping point here.
Posted onMarch 2, 2021|Comments Off on Polar bear attack in Svalbard: victim survives, polar bear does not
A man was attacked from behind this morning by a small male polar bear on the east coast of Svalbard, Norway, where there is abundant sea ice. His companion shot the bear and the victim escaped with minor head injuries. Most bears are very hungry at this time of year because the seal pupping season has not yet begun.
Young bears are extremely dangerous and the most likely to attack people (Crockford 2019; Wilder et al. 2017): a three year old male fatally attacked a camper in August 2020 just outside Longyearbyen, Svalbard, an incident unfairly blamed on lack of sea ice (Crockford 2021).
UPDATE 3 March 2021:Results of an autopsy conducted on the polar bear killed yesterday revealed it was a 6 year old male that weighed only 231 kg, which is less than usual for an adult bear later in the season but likely typical for a relatively young bear at the end of winter before seal pups are born. See quote from a Norwegian polar bear specialist below [my bold]:
Jon Aars, an institute researcher who has spent many years studying bears in Svalbard, told Svalbardposten the vast majority of bears ages six to 15 will weigh between 350 and 450 kilograms in April, when the spring hunting season is typically at its peak.
“It may have been aggressive because it was thin,” he said. “It is likely. The thinner they are, the greater the chance that they are dangerous. He is at an age where he is not frequently considered as a problem bear – it is mostly among the younger or the very old who have problems.”
Posted onFebruary 10, 2021|Comments Off on Polar bear sea ice habitat highs and lows in early February
Sea ice across the Arctic in the first week of February is a mix of highs and lows. Bering Sea is back up to almost normal coverage, as is the Barents Sea. However, ice coverage on the East Coast of Canada is the lowest its been in four decades. This is not yet a worry for polar bears because harp seals don’t pup until mid-March in this region so there is at least four weeks of potential ice growth that can happen before the seals are forced to pup on much reduced ice – where polar bears are sure to find them.
Here is a close-up look at sea ice conditions by region at the edges of the Arctic. Continue reading
Comments Off on Polar bear sea ice habitat highs and lows in early February