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

Abstract

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 km2, 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.

Morphological and histological features of the vomeronasal organ in the brown bear

“…Flehmen behavior is conspicuous in ungulates and carnivores in order to sample pheromones (Evans, ), and bears also seem to uptake pheromones into the VNO via the incisive duct opening to the oral cavity using this behavior (Stirling et al. ).…”

“…As with other carnivores (Adams & Wiekamp, 1984;Salazar et al 1996), the VNO of the bear opened to the mouth. Flehmen behavior is conspicuous in ungulates and carnivores in order to sample pheromones (Evans, 2003), and bears also seem to uptake pheromones into the VNO via the incisive duct opening to the oral cavity using this behavior (Stirling et al 2016). The soft tissue of the VNO in mammals is generally covered by cartilage, although that in rodents (Taniguchi & Mochizuki, 1983;Mendoza, 1993) is surrounded by bone capsule.…”

“…In fact, male polar bears seem to follow single sets of tracks with flehmen behaviors (curling their upper lips and exposing the front gums) to mate with females (Stirling et al. ), and they distinguish sex according to their pedal scents (Owen et al. ).…”

“…As odorants persist for long periods even in the absence of the producer, the vomeronasal system may be a suitable mechanism for transmission of information in bears. In fact, male polar bears seem to follow single sets of tracks with flehmen behaviors (curling their upper lips and exposing the front gums) to mate with females (Stirling et al 2016), and they distinguish sex according to their pedal scents (Owen et al 2015). In addition, male American black bears also show flehmen behaviors during anogenital and excremental investigations (Gonzales et al 2013).…”

Correlates of seasonal change in the body condition of an Arctic top predator

“…no females with dependent cubs) and adults may have been engaged in mating during April–June (Amstrup, ). Since both males and females reduce foraging activity during breeding (Pilfold, Derocher, Stirling, & Richardson, ; Rode et al, ; Stirling, Spencer, & Andriashek, ), spring body condition in our samples might have been lower than that present in the population as a whole.…”