Factors influencing plasticity in the arrival-breeding interval in a migratory species reacting to climate change

Climate change is profoundly affecting the phenology of many species. In migratory birds, there is evidence for advances in their arrival time at the breeding ground and their timing of breeding, yet empirical studies examining the interdependence between arrival and breeding time are lacking. Hence, evidence is scarce regarding how breeding time may be adjusted via the arrival-breeding interval to help local populations adapt to local conditions or climate change. We used long-term data from an intensively monitored population of the northern wheatear (Oenanthe oenanthe) to examine the factors related to the length of 734 separate arrival-to-breeding events from 549 individual females. From 1993 to 2017 the mean arrival and egg-laying dates advanced by approximately the same amount (~5-6 days), with considerable between-individual variation in the arrival-breeding interval. The arrival-breeding interval was shorter for: (1) individuals that arrived later in the season compared to early...