Droughts are expected to increase in frequency and severity with climate change. Population impacts of such harsh environmental events are theorized to vary with life history strategies among species. However, existing demographic models generally do not consider behavioural plasticity that may modify the impact of harsh events. Here we show that tropical songbirds in the New and Old Worlds reduced reproduction during drought, with greater reductions in species with higher average long-term survival. Large reductions in reproduction by longer-lived species were associated with higher survival during drought than predrought years in Malaysia, whereas shorter-lived species maintained reproduction and survival decreased. Behavioural strategies of longer-lived, but not shorter-lived, species mitigated the effect of increasing drought frequency on long-term population growth. Behavioural plasticity can buffer the impact of climate change on populations of some species and differences in plasticity among species related to their life histories are critical for predicting population trajectories.
