An article by CBC News today (3 March 2020) is a surprisingly well-balance report on a recently published paper by Kristin Laidre and colleagues on their work on Baffin Bay polar bears that I discussed last month. It presents the Inuit perspective that polar bears are currently abundant in the area and the population stable despite less summer sea ice and some documented declines in body weight and at least one scientist conceded this is indeed true.
However, the CBC writer still left out the most critical caveat included in the paper about the study: that factors other than changes in sea ice could have affected the body condition and litter size data that the authors documented but they didn’t look at anything except sea ice. This automatically means the conclusions are scientifically inconclusive.
See some quotes below from the CBC article and the caveat from the paper. Continue reading
Posted in Conservation Status, Population, Sea ice habitat
Tagged abundant, baffin bay, body condition, causation, caveat, correlation, polar bear, population size, sea ice, stable
A new paper on Baffin Bay polar bears reports data on body condition and litter sizes collected as part of a major study of the region completed in 2013 compared to sea ice declines since the 1990s; based on a computer model, the authors predict that in 37 years time (if sea ice declines continuously), the incidence of twin litters could “largely disappear.” However, no decline in population numbers was predicted and a critical caveat acknowledges that factors other than changes in sea ice could have affected the body condition and litter size data the authors analyzed, which means the conclusions are scientifically inconclusive.
The last (2013) polar bear population survey of Baffin Bay (SWG 2016) generated an estimate of almost 3,000 (2,826; range 2,059-3,593), which means that regardless of some slight changes in body condition and litter size over the last two decades (which may or may not have been caused by loss of sea ice), there are currently a lot of bears in Baffin Bay.
Posted in Conservation Status, Life History, Sea ice habitat
Tagged baffin bay, body condition, causation, correlation, extinction, fatness, Greenland, litter size, NASA, polar bear, sea ice, weight
In this part of my critique of Stirling and Parkinson (2006), regarding breakup dates in Western Hudson Bay (see Part I here), I will show that these authors also left out critical data.
Figure 1. A bear is transported to Churchill’s polar bear holding facility, from a 2011 Huffington Post article “Polar Bear Prison.”
Their correlation between number of problem bears in Churchill and breakup dates for WHB worked because some very inconvenient data were simply left out: problem bear data for 1983 and 2004.
Inclusion of that information would have shown 1983 and 2004 were two of the worst years for polar bear problems in recent history despite being late breakup years (1983 also had the last human fatality from a polar bear attack). They could have explained why they did not use the data but they did not — they simply left it out.
Amazingly, this work is being touted as “evidence” that global warming is harming Western Hudson Bay polar bears.
Posted in Advocacy, Polar bear attacks, Sea ice habitat
Tagged breakup, cherry-picking, Churchill, correlation, Derocher, early breakup, fatal attack, freeze-up, Kearney, less than healthy science, Ockham's Broom, Parkinson, polar bear, problem bears, Stirling, Towns, western hudson bay