Predator-induced plasticity in nest visitation rates in the Siberian jay (Perisoreus infaustus)

Bird nestlings may be at risk not only from starvation but also from predators attracted to the nest by parental feeding visits. Hence, parents could trade reduced visitation rates for a lower predation risk. Here, through field data and an experiment, we show plasticity in daily patterns of nest visitation in the Siberian jay, Perisoreus infaustus, in response to predator activity. In high-risk territories, jay parents avoided going to the nest at certain times of the day and compensated by allocating more feeding effort to periods when predators were less active. Such modifications in provisioning routines allowed parents in high-risk habitat to significantly lower the risk of providing visitation cues to visually oriented corvid nest predators. These results indicate that some birds modify their daily nest visitation patterns as a fourth mechanism to reduce predator-attracting nest visits in addition to the clutch size reduction, maximization of food load-sizes, and prevention of allofeeding suggested by Skutch. Copyright 2005.