Population recovery following environmental stress is known to depend on demographic structure, life-history and evolutionary dynamics. However, it is unclear how evolution of traits shaped by sexual selection affect population dynamics and recovery. We examined this by manipulating presence/absence of males expressing either a non-aggressive “scrambler” phenotype or an aggressive and lethally armed “fighter” phenotype in soil mite populations of different size. We experimentally altered the male phenotype in populations, subjected them to heat stress, and analyzed their population dynamics and recovery. We show that populations with fighter males exhibited i) reduced population size and stability, ii) greater decline in response to heat stress in larger populations, iii) higher rate of growth, and iv) incomplete population recovery. Such reduced population stability and recovery linked with armed and aggressive phenotypes underlines the importance of sexual selection in mediating population dynamics and resilience to environmental change with implications for managing natural populations.

Population recovery following environmental stress is known to depend on demographic structure, life-history and evolutionary dynamics. However, it is less understood whether the eco-evolutionary dynamics mediated by sexual selection affect population dynamics and recovery after exposure to environmental stress. Here we manipulated the level of sexual selection associated with male aggression in soil mites in populations of different size. By examining their population dynamics and recovery after heat stress, we show that populations facing strong sexual selection exhibited i) reduced population size and stability, ii) greater decline in response to heat stress in larger populations, iii) higher rate of growth, and iv) incomplete recovery to population sizes prior to heat stress. Such reduced population stability and recovery underlines the importance of sexual selection in mediating population dynamics and resilience to environmental change, and has implications for managing natural populations.