Association patterns of African elephants in all-male groups: the role of age and genetic relatedness

Strong social bonds are uncommon among male mammals. In many mammals, however, males form all-male groups, providing opportunities for male-male bonds to emerge. We examined association patterns of male African elephants, Loxodonta africana, in all-male groups and assessed the influence of age and genetic relatedness on these associations. We also examined the influence of age and genetic relatedness on the choice of sparring partners in male elephants. Males had many weak and random associations and few valuable relationships. Male associations were positively correlated with genetic relatedness, suggesting that kinship influences patterns of male associations. Male associations were negatively correlated with age disparity, and males were more likely to spar with other males closer in age to themselves. These results suggest that males associate with other males of similar age in part because sparring may facilitate the development and maintenance of motor and psychological responses to sudden and unexpected events that occur during play; this may help prepare males for male-male competition. We also found that older males had high centrality and strength in social networks, suggesting that older males influence the cohesion of male social groups. Consequently, the elimination of older males from elephant populations by poachers or trophy hunters could negatively affect social cohesion in male elephant groups. Finally, we found that age and genetic relatedness were not significantly correlated, suggesting that male associations based on age and relatedness did not overlap. These findings highlight the complexity of male social relationships in all-male groups. (C) 2011 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.