Cooperation in male lions: kinship, reciprocity or mutualism?

This study examined how male lions in coalitions share access to receptive females and defend their prides. By combining behavioral observation with knowledge of relatedness, the authors found that companions in small coalitions are usually relatives, consistent with kin selection, whereas larger coalitions can include unrelated males who tolerate skewed mating because the alternative is failing to hold a territory at all. The work distinguished mutualism, where all partners benefit immediately, from reciprocity and kin-based help, clarifying the mixed incentives that bind male lions together. It contributed to the broader theory of cooperation by showing that a single species can use different mechanisms depending on group size and relatedness, a finding that continues to inform how researchers interpret alliances among male big cats.