Reproduction under predation risk and the trade–off between current and future reproduction in the threespine stickleback

An increasing number of studies show that animals adjust their reproductive e¡ort to the risk of predation. However, to maximize lifetime reproductive success this adjustment should depend on the animals' and future reproductive potential. Here I tested this hypothesis by allowing threespine stickleback (Gasterosteus aculeatus), differing in current and future mating probabilities, to reproduce in pools in the presence and absence of predators. As expected, males adjusted their reproductive effort to the of predation. Fewer males bred, and all males developed less nuptial coloration in the presence of. However, males with a low current mating probability took less risk than males with a higher probability, whereas all males increased risk taking when future reproductive opportunities. The results thus support the hypothesis that males are able to assess both the risk of predation their current versus future mating probability, and adjust their reproductive decisions accordingly. study further suggests that predation risk may have less effect on sexual selection than previously, as the males which refrained from reproducing in the presence of predators were mainly males a low mating probability.