Context-dependent risk tolerance of the bicolour damselfish: courtship in the presence of fish and egg predators

Reproductive behaviours such as courting, copulation, parental care and mate guarding often entail a cost of increased predation risk, either to the individual itself or to the offspring under its care. Because of this, males of several species reduce courting effort in the presence of a predator. The degree to which reproduction is curtailed may depend upon the magnitude of potential benefits as well as the current and previous reproductive success of the male. We presented male bicolour damselfish, Stegastes partitus, with females in the presence and absence of fish and egg predators and tracked the realized fecundity of the males over the course of a spawning cycle to evaluate the degree to which courting reductions depend on the size of the female being courted, the type of predator involved and the previous and current mating success. We found that males increased courting towards larger females and that this courting was reduced in the presence of a fish or an egg predator for small females but not for large ones. We found no relationship between courting reduction and either past or current reproductive success for the fish or egg predator treatments, respectively. Our results demonstrate that male S. partitus do show context-dependent courting behaviour and seem to balance risk and reward in courting decisions.