Are polar bears endangered?
The short answer is ‘no’. They are officially recognized as a Threatened Species by the United State Fish and Wildlife Service, which named them to that category in May of 2008.
At the time, a lot of controversy surrounded the designation. Many pointed to the apparent increase in official population estimates over the past several decades. However, it’s now thought that these fluctuating numbers reflect increased research and efforts to count the populations in various Arctic regions, rather than actual increases in population. Prior to the 1960s, much of the estimates came from hunters and local villagers. As scientific research on the bears gathered momentum in subsequent decades, more accurate counts were obtained.
As global warming increases, it is expected that polar bears will suffer along with other polar life. Where warming of a few degrees in the temperate parts of the planet may affect rainfall patterns and crop production to an extent, a couple of degrees in the Arctic can have a profound effect. Once the temperature rises above the freezing point of water, ice melts and can no longer provide the needed habitat for either polar bears or many other species including the bears’ prey, seals.
Are Polar Bears Endangered in Churchill?
Global warming also affects the formation and movement of sea ice in different Arctic regions. Therefore it can affect local populations of polar bears differently. The polar bear population of the Churchill, Manitoba region, one of the most studied populations by scientists, has decreased markedly in the last two decades — on the order of 25%. This has prompted at least one scientist, Alberta’s Andrew Derocher, to claim this southern population of bears could become unable to successfully reproduce within a few decades. See Churchill Polar Bears Endangered in our news blog.
Randy Green, a naturalist and photographer who has been photographing polar bears in the Churchill area for almost 30 years, has seen profound changes in the bears’ habitat during that time. “Freeze up of the Hudson Bay shore used to reliably occur by about the end of the first week of November each fall. Now, it can be well after Thanksgiving or the last week of the month. The sea ice is melting earlier in the spring by about the same amount, which means the bears are getting around a month less time on the ice to hunt seals. This translates to less calories consumed, and therefore less body weight.”
Less body weight is exactly what scientists are seeing in the Churchill population. If conditions continue to warm, this is undoubtedly a barometer of what other populations of polar bears further north will encounter.
For one of the best works on polar bear adaptations and evolution, read Canadian polar bear researcher Dr. Ian Stirling’s book Polar Bears. You can find the book on Amazon – clicking on the link below will open in a new window.