Ghalambor, C. K., S. I. Peluc, and T. E. Martin. 2013. Plasticity of parental care under the risk of predation: how much should parents reduce care? Biology Letters 9: 20130154.
Predation can be an important agent of natural selection resulting in divergent parental care behaviors, and can also favor behavioral plasticity. Parent birds often decrease the rate that they visit the nest to provision offspring when perceived risk is high. Yet, the plasticity of such responses may differ among species as a function of either their relative risk of predation, or the mean rate of provisioning. Here, we report parental provisioning responses to experimental increases in the perceived risk of predation. We tested responses of 10 species of birds in north temperate Arizona and subtropical Argentina that differed in their ambient risk of predation. All species decreased provisioning rates in response to the nest predator but not a control. However, provisioning rates decreased more in species that had greater ambient risk of predation on natural nests. Thus, extent of plasticity varied among species in accord with risk.