Pied flycatchers are migratory summer visitors to upland oak woodland whose welfare is affected by timing mismatches between arrival and caterpillar peak caused by climate change.
Pied flycatcher welfare at breeding sites is increasingly compromised by phenological mismatch. When caterpillar peak passes before chick hatching, adults must work harder to find declining prey numbers, reducing chick feeding rates and increasing starvation risk. Chick starvation is a significant welfare cost in years of severe mismatch. Nestbox provision is one of the most effective and practical welfare interventions, increasing nesting success in areas where natural cavities are scarce. Long-term nestbox programmes that monitor breeding performance provide welfare data as well as population information.