Wolf (<i>Canis lupus</i>) Predation of a Polar Bear (<i>Ursus maritimus</i>) Cub on the Sea Ice off Northwestern Banks Island, Northwest Territories, Canada

Abstract

We describe the apparent predation of a polar bear (Ursus maritimus) cub by wolves (Canis lupus) on the sea ice just off the northwest coast of Banks Island, Northwest Territories, Canada. On 20 April 2004, while following the tracks of a female bear and two cubs-of-the-year in the snow during a helicopter survey, we noted that the bear tracks had been joined by several sets of wolf tracks. After following both sets of tracks for about 1 km, we observed a disturbed area in the snow with numerous overlying tracks. Upon landing and searching the site, we found the remains of a polar bear cub that the wolves had successfully separated from its mother and killed. This is only the second documented observation ever made of a polar bear killed by wolves.