Genetic relatedness, coalitions and social behaviour of white-nosed coatis, Nasua narica

The white-nosed coati, Nasua narica, lives in large social groups, called bands, and displays a variety of complex cooperative behaviours. These behavioural patterns, such as coalition support, may influence the ability of an individual to gain access to limited resources and have attracted theoretical attention because they may be maintained by reciprocal altruism. To better understand the mechanisms influencing cooperation, coalition dynamics and time individuals spend away from the band, the relationship between kinship and specific social behaviours was assessed. The genetic relationships of individuals from six coati bands were estimated by measuring the similarity of multilocus DNA fingerprints. Results showed that coati bands primarily consist of highly related individuals. The variance in relatedness was high, however, and four bands contained some individuals that were unrelated to other band members. Males who monopolized access to band females during the breeding season did not sire most offspring. Unrelated individuals spent more time away from the group than did band members with close relatives in the band. Moreover, unrelated individuals received more aggression from band members and received less coalition support than did individuals with close relatives in the band. (C) 1997 The Association for the Study of Animal Behaviour.