Polar bear predation of ringed and bearded seals in the land-fast sea ice habitat

Abstract

Predation of seals by the polar bear, Ursus maritimus, was not significant in the Western Arctic. In the High Central and Eastern Arctic, and along southeastern Baffin Island, bear predation of the subnivean lairs of ringed seals, Phoca hispida, was common. The ice types hunted by bears differed between the High Arctic and southeastern Baffin Island. However, no difference was seen in the proportion of successful kills. There is strong evidence that the bearded seal, Erignathus barbatus, is an important prey species of the polar bear in southeastern Baffin Island. Polar bears mainly kill newborn pups in their birth lairs. The prime breeding habitat of ringed seals located in ice hummock areas is less successfully preyed upon by bears than other ice types. Several factors such as the complexity of birth lairs and possible olfactory confusion might account for this. Seals under 2 years of age are those most frequently killed by bears. Data are presented to show that harvesting these age-classes provides the maximum return of energy to the bear and results in the least harm to the prey population.