Dispersal Patterns of Maternal Polar Bears from the Denning Concentration on Wrangel Island

Twenty-one female polar bears (Ursus maritimus) accompanied by cubs of the year were fitted with satellite transmitters upon emergence from maternal dens on Wrangel Island during spring 1990. Movements during the following year indicated no subsequent geographic segregation in the Chukchi or East Siberian seas of females that denned in various regions of Wrangel Island. Movements encompassed the eastern half of the East Siberian Sea, the entire Chukchi Sea, extreme western portions of the Beaufort Sea, and portions of the Bering Sea lying north of Saint Matthew Island. One-third of the marked females over-wintered in the active shear zone, which lies along the northern shoreline of the Chukotka Peninsula in Soviet territory.