Non‐photic environmental cues and avian reproduction in an era of global change

Abstract

Ultimate factors such as food availability and weather create optimal windows of time for birds to reproduce. However, within a given year, birds must rely upon proximate environmental information such as photoperiod, food, temperature, social cues and other factors to anticipate when that window will occur and prepare physiologically for breeding. While avian responses to photoperiod are relatively well understood, less is known about how birds use non‐photoperiodic information in reproductive timing decisions – even though understanding how birds use non‐photic cues is an important component of predicting their responses to global change. We review research on the regulation of reproductive physiology and clutch initiation by non‐photic cues within and across avian species. We evaluate hypotheses in the literature about the integration of photoperiodic and non‐photic cues in reproductive timing and about differences in non‐photic cue‐use between the sexes and across species. We show how regulation of reproduction by non‐photic cues may influence species’ responses to climate change and highlight research opportunities moving forward.