The common swift has declined significantly in the UK, losing nesting sites as buildings are renovated and insect prey populations collapse.
Swift welfare is primarily affected by nest site loss during building renovation and reduced food availability from insect decline. Adults that lose established nest sites after years of return fidelity experience significant disruption to breeding success. Chicks in nests affected by renovation may face death by disturbance or nest loss. Swift boxes integrated into buildings during renovation are an effective mitigation measure. Insect conservation through pesticide reduction benefits individual swifts through improved prey availability.