Polar bears are not doing all right
Editor: Jim Church has forcefully contradicted a key finding of a NatureServe Canada report, “On Guard For Them,” that polar bears are at-risk, “vulnerable” to extinction if we don’t protect them (Polar bear population is booming, April 15).
Citing the International Union for the Conservation of Nature (IUCN) and the U.S. Fish and Wildlife Service (USFWS), Church says both organizations reported a 16 per cent increase in polar bear populations worldwide between 2005 and 2015.
He caps off his argument by pointing to a Globe and Mail report of a Nunavut government survey that he says found a 66 per cent increase in the bear population.
He suspects a conspiracy is afoot — that polar bears were added to the international at-risk list “for political purposes because the data doesn’t support such a drastic measure.”
My research indicates Church is wrong. The IUCN Red List of Threatened Species currently assesses polar bears as “vulnerable,” while the USFWS Species Profile for Polar bear assesses them as “threatened.”
The Globe and Mail makes clear that the Nunavut survey was conducted in 2012 and was concerned with estimating the number of bears along the western shore of Hudson Bay. The estimate was 66 per cent higher than scientific modelling predicted the population would be.
I could not find the survey to learn more.
According to the National Post, a follow-up report by the Nunavut government was conducted this year. I went to the report itself, which says that the bear population in Kane Basin was stable or increasing, while in Baffin Bay, population trends were uncertain due to “several limitations” of the available data.
The body condition in Baffin Bay polar bears had declined, however, “in close association with the duration of the ice-free period and spring sea ice transition dates. This is consistent with the hypothesis that reduced time on the sea ice (and presumably declining access to prey during spring to early summer) is a primary mechanism driving this decline.”
In other words, the Baffin Bay bears were skinnier than they used to be. As for the Kane Basin bears, the scientists noted that if trends in diminishing sea ice due to climate change were to continue, they would likely experience similar negative impacts.
The National Post contacted research biologist Ian Stirling, “a world-recognized expert on all things polar bear,” for comment.
“The underlying concept is pretty simple,” he said. “Bears need sea ice as a platform from which to hunt seals.”
Other food sources such as sea birds or ground squirrels will not provide the nutrition they need.
“The idea that they are just going to adapt somehow to a largely different ecological environment that they have been evolving into for a few hundred thousand years is simply unrealistic wishful thinking,” said Stirling.
We could safely conclude that the NatureServe Canada report is correct. If we don’t find a way of protecting polar bears, they will become extinct. Dianne Varga, Penticton