Activity and movement patterns of polar bears inhabiting consolidated versus active pack ice

Abstract

We investigated the influence of ice conditions on activity and movement patterns of polar bears in the Canadian-West Greenland Arctic. We used radiotelemetry data gathered over 11 years (1989-99) from 160 adult female polar bears to test for differences in movement and activity of bears inhabiting active ice and consolidated ice. Bears inhabiting active ice moved more than those inhabiting consolidated ice (12 versus 8 km/day), but their activity throughout the year did not differ (bears of both groups were active for 21% of the day). Differences in activity and movement of bears in the two study areas appeared to be related to differences in predominant ice conditions and presumed prey availability. Seals, particularly juveniles, are most plentiful in spring and summer, when polar bears moved more and were most active. During winter, when juvenile seals were less available in consolidated ice areas, bears in that habitat were less active and moved less than bears in active ice areas. Polar bears have evolved flexible patterns of seasonal activity, movements, and facultative den use as adaptations to different sea-ice environments.