Abstract

Most organisms exhibit phenotypic plasticity as an evolved response to environmental variation; hence there is widespread hope that adaptive plasticity might lessen the detrimental impacts of environmental change on individuals and populations. Here, I discuss the special role that plasticity in behaviour can play under rapid environmental change. This role arises because behavioural modes of plasticity are common and permit relatively rapid and reversible responses to changing conditions. Key issues are the degree to which behavioural plasticity improves individual fitness, and the impact that plasticity has on population persistence. Behavioural plasticity is quite often beneficial for individuals, and in some cases accounts for most of the observed phenotypic response to environmental change. However, there are several reasons for expecting that maladaptive behavioural plasticity may be especially important in the context of anthropogenic impacts, and the many reports of ecological traps suggest that maladaptive responses to environmental changes caused by humans are widespread. The population-level consequences of plasticity are not well studied, but limited evidence suggests that behavioural responses have enabled persistence or reduced population declines. I conclude by highlighting several topics on which further research is needed.