ECKHARDT, G. H. *; WATERMAN, J. M.; ROTH, J. D.; Univ. of Central Florida; Univ. of Central Florida; Univ. of Central Florida: The functional significance of play fighting in polar bears: are they asocial?

Polar bears, Ursus maritimus, are widely considered asocial animals. Yet while waiting for the sea ice to form near Churchill, Manitoba, male polar bears engage in play behavior, including rigorous play fighting when temperatures start cool in October and November. These energetically costly play bouts last from 15 seconds to 43 minutes, yet rarely result in injury. We collected detailed observational data in the fall seasons of 2001 and 2002 to examine the functional significance of this play behavior. From vehicles modified for travel on the tundra we recorded (a) body size, (b) use of space and (c) time budgets of individual bears, as well as (d) sizes of aggregations and (e) detailed components of male-male interactions. Play fighting included few aggressive components, comprising <5% of all play components; however these components varied in frequency among different individuals or dyads. Patterns of initiation of play fighting did not support self-assessment as a function of play, while patterns of termination did. Data suggested that males may form a dominance hierarchy on land during the fall season. Play in adult animals is very rare, especially between individuals that are so aggressive at other times of the year, and our data suggest that the play interactions that take place in the fall at Churchill could have an important influence on the spring mating season.