Polar Bears Coping With Climate Change: Migrating North and Altering Appetites
Global warming caused arctic melting is pushing polar bears further to the Canadian archipelago, where sea ice melts slower than mainland ice.
A new US Geological Survey study reveals the movement on the basis of DNA analysis. It showed that 19 existent polar bear subpopulations can be classified into four clusters namely astern Polar Basin, Western Polar Basin, Canadian Archipelago, and Southern Canada. DNA analysis revealed a gene flow towards Canadian Arctic Archipelago over the last 15 to 45 years, Discovery News reported.
"The polar bear's recent directional gene flow northward is something new. In our analyses that focused on more historic gene flow, we did not detect movement in this direction," said Elizabeth Peacock study's lead author said in a news release.
"By examining the genetic makeup of polar bears, we can estimate levels and directions of gene flow, which represents the past story of mating and movement, and population expansion and contraction. Gene flow occurs over generations, and would not be detectable by using data from satellite-collars which can only be deployed on a few polar bears for short periods of time," Peacock said.
Gender differences in gene flow analysis showed researchers that females were likely to stay in the area of their birth than males. However it may be difficult to prove this hypothesis as male bears have thick necks, making collaring difficult.
The study also showed that there modern polar bears are result of hybridization with brown bears, as scientists confirmed that hybrid bears observed in Northern Beaufort Sea region of Canada is a localized phenomenon, Chicago Tribune reported.
