The polar bear has become a symbol of climate change and the impact it has on life on this planet. The polar bear was listed under the United States’ Endangered Species Act due to the threat global warming is posing on the Arctic environment the bears call home. A new study is now indicating that polar bears may face a more perilous future than previously believed.
Researchers from the University of Alberta and York University in Canada recently published their study regarding polar bears in the journal Biological Conservation. The researchers used different methods to study the impact climate change will have on the species as a whole. Rather than studying individual polar bears through mark and release methods, the researchers predicted the impacts of climate change on different aspects of polar bear life instead.
The researchers developed models of polar bear behavior, physiology and ecology in order to predict their fate. The method of capturing bears to study them and releasing them leads to what the researchers stated were just educated guesses based on extrapolations. Such methods lead to increased errors in predictions. However, the Canadian researchers’ methods based their predictions on daily polar bear life and the impact disappearing sea ice will have on them.
For example, polar bear mating ecology. The researchers stated: “We developed a model for the mating ecology of polar bears. The model estimates how many females in a population will be able to find a mate during the mating season, and thus get impregnated.” Since male polar bears track females via sea ice, diminishing sea ice will impact the number of male-female interactions which will occur and thus impact reproduction rates.
Some polar bears are forced to fast during summer months without sea ice. The researchers created a model to determine how long a bear would survive depending solely on their fat and protein deposits. This model enabled the researchers to determine the impact starvation would have on populations. This concern is currently minimal, however, the researchers state that an increase from four to six months of fasting will cause a much as half of the males to perish.
Overall, the researchers point to the fact that current studies on polar bears and climate change are inadequate due to the methods used. One of the researchers, Dr. Peter Molnar from the University of Alberta, stated: “Canada has about two-thirds of the world’s polar bears, but their conservation assessment of polar bears didn’t take climate change seriously.”
The researchers have indicated that they believe polar bears will reach a so-called to tipping point. Once circumstances such as those discussed in their study occur, polar bear populations will drastically decline in number. To read further about the models the researchers developed please see the journal Biological Conservation.
