Grizzlies Invade Polar Bear Turf

Climate change prompts northward migration for grizzlies

• Fiona Rollins
• Apr 01, 2005

POLAR BEARS may have more to deal with than warming temperatures, which cause the sea ice they depend on for survival to melt. As the thermostat rises, grizzly bears are slowly expanding their range into the higher Arctic, leaving scientists wondering about the ecological impacts of the new arrivals.

Paw prints and DNA evidence confirm that a grizzly trekked farther north than ever before, making it to Melville Island, about 620 miles north of the Arctic Circle. The bear was first spotted in 2003, and has continued to linger in the area. Other grizzly sightings over the past few years have shown the bears making themselves at home in regions previously considered too chilly.

Grizzlies have been bred with polar bears in captivity, but scientists aren’t sure if the species would intermingle in the wild. The two species have different prey—grizzlies preferring musk oxen to the polar bears’ favored seals—but both are known to eat cubs, a practice which could hurt already-threatened polar bear populations.