Posted onOctober 15, 2021|Comments Off on No signs of a climate emergency for W. Hudson Bay polar bears this year ahead of UN climate meeting
I’ve been told that another complete aerial survey of the Western Hudson Bay polar bear subpopulation (from the Nunavut to Ontario boundaries) was conducted in August this year and that the bears have been hanging out further south than usual. It will be years before the results of the population count are published, of course (especially if it’s good news) but my contacts also say virtually all of the bears are in great condition again this year.
Posted onOctober 7, 2021|Comments Off on Alaska polar bear researchers claim poor sea ice limited spring field work in 2021 more than 2019
According to an Inside Climate Newsreport, polar bear researchers at the US Geological Survey had trouble darting bears in the Southern Beaufort Sea in March-May of 2019 and 2021. They claim their research program was hampered by thinner-than-necessary ice for safely landing the nearly 4,000 lb. outfitted helicopter (with crew and gear) in 2019 but that conditions in 2021 were even worse (it is implied work proceeded in 2020 despite pandemic restrictions but no data for that year are discussed).
However, this claim of worse conditions in 2021 is not corroborated by reports from sea ice experts and ice charts for the Southern Beaufort this spring, where thick first year and multiyear ice was present from March through June. Ice didn’t begin to pull away from landfast ice to form patches of open water near the Canadian border until late April 2021 compared to early May in 2019 (as it did in 2016), as shown in the video and charts below. Moreover, the researchers oddly fail to mention that the presence of thin ice and open water in spring is essential for polar bear survival in the Southern Beaufort, a fact which has been documented and discussed in the scientific literature by their colleagues.
Note the latest survey of the Chukchi Sea estimated about 3,000 bears inhabit the region (AC SWG 2018; Regehr et al. 2018), at least 1,000 more that the figure of 2,000 used in recent IUCN assessments and survival predictions (Amstrup et al. 2007; Regehr et al. 2016; Wiig et al. 2015). Wrangel Island is the primary terrestrial denning area in the Chukchi Sea (Garner et al. 1984; Rode et al. 2014) and a recently published study showed that the body condition (i.e. fatness) and litter size of Chukchi Sea polar bears has not been negatively affected by low summer sea ice (Rode et al. 2021).
Posted onSeptember 15, 2021|Comments Off on Still waiting for two thirds of polar bears worldwide to disappear due to lack of summer sea ice
It’s hard to believe that a polar bear specialist would claim that their predictions have come true, given the facts of the matter: that polar bears arguably number over 30,000 worldwide and regions with the most dramatic sea ice declines have not documented reduced polar bear health or survival. But in mid-July this year, Andrew Derocher – one of the field’s most vocal promoters – did just that: proclaimed on twitter that “virtually all of our predictions are coming true.” Except, none of them did, especially the most widely-promoted one, which failed spectacularly.
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
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Posted onAugust 9, 2021|Comments Off on Tipping points, Attenboroughesque narratives of climate doom and dying polar bears
Outlandish ‘tipping point’ rhetoric is about to be regurgitated once again during the promotion of the latest IPCC report, due today. Tipping points are those theoretical climate thresholds that, when breeched, cause widespread catastrophe; they are mathematical model outputs that depend on many assumptions that may not be plausible or even possible.
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 onJune 2, 2021|Comments Off on New survey estimates 10x as many polar bears in Russian section of Chukchi Sea as in USA portion
A joint US/Russian aerial survey has estimated that a minimum of 3,435 polar bears (but possibly as many as 5,444) likely inhabited the Chukchi Sea in 2016, quite a bit more than a previous study that estimated a population size of 2,937 the same year (which used data from one small US area extrapolated to the entire region).