House martin populations are declining; their welfare and conservation depend on availability of nesting sites on buildings and access to aerial insect prey.
House martin welfare is most threatened by nest site loss from building renovation and construction that eliminates traditional eave nesting opportunities. Breeding failure from poor weather reduces chick survival. Individual birds returning to find nest sites destroyed face the energetic cost of reconstruction or nest site failure. Welfare conservation requires maintaining existing nest sites during renovation, installing artificial cup nests on appropriate buildings, and supporting insect-rich habitats that provide adequate prey during the breeding season.