ANCHORAGE, Alaska, Jan. 8 (UPI) -- As habitats to the east and south of the Arctic region become more unstable -- and as suitable habitat continues to erode -- polar bears are relocating to far-northern Canada, where sea ice is plentiful and reliable.
In analyzing the genetic makeup of local polar bear populations, scientists with the U.S. Geological Survey found that over the last three generations (beginning in the 1990s) polar bears have been slowly migrating north -- to the Canadian Archipelago, where there is sea ice year-round.
"Instead of sort of random movements of bears across the Arctic that we found in sort of the more ancient historical picture, we found directional movement towards the Canadian Archipelago," Lily Peacock, a wildlife biologist with USGS, told Alaska Public Radio Network (APRN).
Scientists say this type of gene analysis, using collected blood samples, offers a wide-angle, long-term perspective that isn't possible by simply tracking bears via satellite.
"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," Peacock explained in a press release. "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."
Though the shift in genes is gradual, rendered over several generations, researchers say the trend could accentuate the species' vulnerability in the future. As a population becomes isolated it is at greater risk of extinction.
"And what can happen when populations of animals become isolated is that they can blink out if something happens," Peacock told APRN. "If they have a bad winter or bad spring and that stresses the population and it gets smaller and smaller, but the migration corridor has been cut off and you can't repopulate."
The work of Peacock and her colleagues was published in the journal PLOS ONE.