Female monopolizability promotes within-community killing in chimpanzees [post]

Michael L. Wilson, Anthony Massaro, Emily Wroblewski, Deus Mjungu, Emily Boehm, Nisarg Desai, Steffen Foerster, Rebecca Rudicell, Beatrice Hahn, Anne Pusey
2021 unpublished
Male chimpanzees (Pan troglodytes) defend group territories and sometimes kill members of rival communities — a pattern often compared to human warfare1-3. Male chimpanzees also sometimes kill grown males from their own community4-9. Such within-community killings are puzzling, as they reduce the coalition strength needed to win inter-community contests5,10. Here we examine the contexts of within-community killing using data from two neighboring communities at Gombe National Park, Tanzania, as
more » ... ell as published data from other long-term chimpanzee study sites. At Gombe, more killing occurred within the smaller Mitumba community, where fertile females were more monopolizable. Attackers increased their share of mating and paternity following known and inferred killings. Other factors proposed to explain such killings, including the degree of intercommunity threat, male-biased sex ratios, high population density, or generalized aggression, did not explain the high rates of killing in Mitumba. Comparing across study sites, the best predictor of within-community killing was an index of the degree to which fertile females can be monopolized by the highest ranking male11. Our findings therefore support the hypothesis that within-community killing is a strategy to eliminate reproductive rivals that is more likely to pay off when fertile females are more easily monopolized.
doi:10.21203/rs.3.rs-163673/v1 fatcat:uiiah5fnrzfn3gkckvsjgy3tie