An uneasy alliance: unequal distribution of affiliative interactions among members of a captive wolf pack

Abstract

The social groups of many vertebrates may be characterized as "uneasy alliances" that reflect tensions between benefits of group membership and costs to individual fitness among members, especially nonrelatives. The prebreeding season may be a time when these tensions become most acute and so observable for packs of gray wolves (Canis lupus). We recorded affiliative (play) interactions among two females and five males of known social ranks in a captive pack as the time of breeding approached. Substantial inequalities among pairs of wolves were apparent in frequencies of both the initiation of play and the exhibition of positive responses by recipient wolves. With the subsequent arrival of the breeding season, the pack experienced social disruption that led to the eviction of the original alpha male and a reordering of the ranks of those wolves remaining. Our data suggest that unequal affiliative interactions among pack members can be associated with (and, perhaps, even be predictive of) subsequent social disruption at a time when opportunities for personal reproduction become most available.