Common swifts have declined by over 60% in the UK since the 1990s, primarily due to loss of nesting sites in modernised buildings - a welfare and conservation crisis with clear solutions.
Swift welfare is primarily threatened by nest site loss due to building renovation. Breeding failure caused by lost nest sites represents a direct welfare harm to adult birds, who invest heavily in site fidelity and lose a season's reproductive effort. The broader population decline is itself a welfare concern - reduced population density may affect flock-based behaviours and pair formation. The practical solution - swift bricks and nest boxes - is low-cost and highly effective, making swift conservation one of the most achievable urban wildlife welfare interventions.