Behavior and activity budgets of wild breeding polar bears (Ursus maritimus)

We quantify the first complete description of breeding behavior and activity budgets of an undisturbed pair of adult polar bears, observed 24 h/d for 13 d from 2 to 15 May 1997, at Radstock Bay, Devon Island, Nunavut, Canada. The male herded the female to an area of 1-2 km(,)(2) where we observed them throughout the observation period. All behaviors were documented from when the adult female and her 2.5-yr-old cub were first observed being followed by an adult male, through separation of the cub from its mother, a week of intense interactions preceding several days with copulation, after which they parted. They mated for 51, 86, 66, and 150 min on 9-10, 12, 13, and 14 May, respectively, and parted on 14-15 May. The male deterred three challengers. The peak breeding season for polar bears runs from early April through mid-May, although additional mating behavior has been documented in June. Timing of mating and duration of copulations in the wild were similar to reports from zoos. Induced ovulation, male intrasexual competition, female fitness, the mating system, and potential consequences of climate warming are discussed with insights made possible by documentation of the reproductive behavior of wild polar bears.