Genetic Consequences of Dispersal and Social Behavior in Lions, Panthera leo

Abstract: This thesis combines behavioral observations of African lions (Panthera leo) with genetic analyses, in an attempt to clarify causes and consequences of lion group living. The numerous complex cooperative behaviors of lions present an excellent opportunity to investigate the evolution and maintenance of group living. This thesis focuses on female group living and male dispersal patterns.Lion sociality is found to be more complex than previously thought. Short dispersal distances result in strong kinship ties among prides, creating the potential for kin selection to operate among prides. Simultaneously, some prides contained unrelated females, depriving females in such prides of inclusive fitness benefits from group living. Concurrent with short dispersal distances in both males and females, significant genetic differentiation could be detected over relatively short distances in analyses of males. Extensive behavioral observations showed that territorial behaviors were unaffected by kinship ties to intruders. Instead, favorable odds and several environmental conditions were important factors. Space use analyses showed large overlap among prides. Again, kinship did not affect degree of overlap. Conclusively, these results show that the ultimate causes of lion sociality remain elusive, but that kin selection may be less important than generally thought. Lion sociality seems to be explicable mainly in terms of direct fitness benefits, which therefore should be given more attention.