ADOPTION IN AFRICAN WILD DOGS, LYCAON-PICTUS

Parental care of unrelated young is occasionally misdirected and malad aptive from an individual fitness perspective (e.g. interspecific broo d parasitism). Alternatively, adults may 'adopt' dependent young and g ain direct benefits irrespective of the degree of relatedness. For soc ial species whose fitness is partially a function of group size, direc t benefits of increasing group size may provide a mechanism favouring adoption independently of the inclusive fitness consequences. African wild dogs, Lycaon pictus, are social carnivores for which group size h as been positively correlated with reproductive success and competitiv e ability. Co-operative breeding by wild dogs has been described previ ously as strongly kin-selected and helpers were assumed to be invariab ly closely related to offspring. However, observations from this study show that the assumption that helpers are related to those they help is not always valid. A minimum of 25% of study area packs (n = 12) con tained nonbreeding adults that provided parental care for unrelated pu ps. Costs of adopting unrelated weaned wild dog pups are slight or non existent except for delayed costs due to late potential conflict with mature same-sex adoptees over access to mates. Immediate and delayed d irect benefits identified here are associated with increasing group si ze and may indicate important mechanisms underlying adoption and the e volution of helping behaviour in wild dogs.