Data from: Responses of the collared flycatcher to the changing climate: a comprehensive view

Global climate change involves various aspects of climate, including precipitation changes and declining surface wind speeds, but studies investigating biological responses have mainly focused on the impacts of rising temperatures. Additionally, related studies on bird reproduction often focus on breeding onset, even though the sensitivity of a species can vary among different breeding components influenced by diverse weather aspects. We used an almost four-decade-long data set to investigate how the different aspects of breeding parameters of a collared flycatcher (Ficedula albicollis) population in the Carpathian Basin were associated with various local weather parameters. We also investigated the temporal trends of weather and breeding parameters. Higher temperatures and lower wind speeds were accompanied by earlier breeding onset. Breeding season length correlated positively with rains and negatively with the magnitude of within-season temperature rise. Hatching delay increased with cooler temperatures and rainier weather. Clutch size increased with the number of cool days. There were significant temporal trends in all breeding variables and, in parallel, the related weather parameters. For example, an advance in breeding onset and a decrease in wind speed were observed. The phenological mismatch between prey availability and breeding has notably increased in the last decade. Our results highlight the intricate interplay between climate change and the reproductive patterns of migratory birds, emphasizing the need for a holistic approach. It also underscores the potential threats posed by climate change to bird populations and the importance of adaptive responses to changing environmental conditions.