Climate Change May Drive Polar Bears Into Humans’ Backyards

Climate change is melting some polar bears’ habitat and forcing them to spend significantly more time on land, a new study has found. The change will likely throw off the Arctic ecosystem and increase the animals’ interactions with humans.

The study, published Wednesday in the journal PLOS One, compared the behavior of female polar bears fit with satellite radio collars in the Chukchi Sea region, the area between Russia and Alaska, between the 1986-1995 and 2008-2013 summer months. Only female bears were studied because male bears’ necks are wider than their heads, making the collars easy for them to slip off.

Researchers found that there were substantially fewer days of sea ice in the region during the later time period. In the north, ice retreated 20 to 40 days earlier then than it did between 1986 and 1995, while in the south, it retreated as much as 15 days earlier.

Polar bears spend their days on the ice, hunting seals, so the changes meant they had to spend a lot more time on Russia’s Wrangel and Herald Islands. The proportion of bears spending more than seven days on land between August and October nearly doubled, from 20 percent in 1986–1995 to 38.9 percent in 2008-2013, with the average amount of time spent on shore increasing by 30 days.

That increased amount of time on land could force the polar bears to prey outside their usual diet, creating serious implications for the Arctic’s ecosystem.

“Several studies in areas where bears are coming onshore earlier and spending more time on shore have documented localized but intense nest predation of sea birds and geese,” the study notes. “On Wrangel Island, Russia, polar bear predation resulted in the death of at least 226 walruses … between 1989 and 2006, —> Read More