Sex-specific influence of communal breeding experience on parenting performance and fitness in a burying beetle

Communal breeding, wherein multiple conspecific individuals live and reproduce together during a single breeding event, may generate immediate benefits in terms of defence and reproduction. However, the carry-over effects of events in communal breeding on individual behaviour and fitness remain less studied. We experimentally tested the immediate and carry-over effects of communal breeding on parenting performance and fitness in the burying beetle (Nicrophorus vespilloides). These beetles bury carcasses as food resource for their offspring and themselves, and provide extended care to the developing larvae on the buried carcass. We subjected individuals of varying sizes to communal (i.e. group-breeding) or non-communal breeding (i.e. pair-breeding) experience during their first breeding event, and subsequently to non-communal breeding during their second breeding event, and measured parental effort and reproductive success during both breeding events. In communal groups, large individuals became dominant and monopolized the carcass. At the first breeding attempt, large males in communal groups spent more time providing care than large males in non-communal groups, while such a difference was not observed for large females and small females or males in communal and non-communal groups. Reproductive success was similar for individuals that bred in communal and non-communal groups during their first reproductive event, indicating no significant immediate benefits of communal breeding in terms of reproduction. Compared to males that originated from non-communal groups, males from communal groups produced a similar number, but heavier larvae during their second breeding attempt, whereas such an effect was not observed for females. Our results provide evidence for sex-specific effects of communal breeding experience on parenting performance and fitness. Such observed sex differences in carry-over effects of communal breeding on fitness may generate sexual conflict over parental effort in social animals.