Avian seasonal reproduction in times of global warming:Insights from evolution, ecology and (epi-)genomics

In this thesis, I focused on avian seasonal reproduction in times of global warming in the great tit study population at the Hoge Veluwe. I assessed the evolutionary implications of the phenological mismatch between chick feeding and prey abundance and the genomic basis of lay dates in great tits with a focus on DNA methylation. The main conclusions are that (1) recent variability in global warming weakened the phenological mismatch and directional selection on lay dates in the study population, but long-term global warming will again lead to an intensified phenological mismatch, (2) genomic selection for early and late lay dates led to an asymmetric phenotypic response under wild conditions, indicating the presence of constraints on advanced lay dates, (3) DNA methylation in blood has limited potential to reflect functional signatures of DNA methylation in ovary (and potentially other target tissues) without prior validation and (4) genomic variation for lay date in great tits resides in temperature-sensitivity offering a potential mechanism at which selection can take hold in the study population. However, I did not fully resolve the questions of the evolutionary implications of the phenological mismatch and the genomic architecture of lay dates in great tits. Hence, we need further studies to derive robust predictions for the potential of great tits and other wild bird species to adapt to global warming