Wild Swift Population Decline and Building Conservation

Swifts are declining rapidly in the UK due to loss of nest sites in renovated buildings; their welfare and conservation depend on built environment changes.

Key Facts

Swift populations declined by approximately 53% in the UK between 1995 and 2019
Swifts nest almost exclusively in buildings, using cavities under eaves and in older walls
Building renovation that seals eaves and soffits destroys nest sites that swifts return to yearly
Swifts mate for life and show strong nest site fidelity - site loss has lasting population effects
Swift bricks and boxes can provide replacement nest sites when fitted correctly
New buildings in some areas are now required to include swift nest provision
Swifts spend almost their entire lives airborne, only landing to nest
The UK swift nesting season runs from May to August - renovation should avoid this period

Welfare Considerations

Swifts returning to find nest sites sealed by renovation face significant welfare consequences. Site-faithful birds expend substantial energy attempting to re-enter blocked sites. Loss of nest sites prevents breeding and drives population decline. The welfare of individual swifts is best protected by avoiding building works that affect nest sites during the nesting season, installing swift nest provisions when renovating, and advocating for planning requirements that mandate swift bricks in new developments. RSPB and Swift Conservation provide expert guidance.

What You Can Do

Check buildings for swift activity before starting any renovation work between May and August
Install swift bricks or nest boxes when renovating or building - Swift Conservation provides guidance
Advocate for local planning policies that require swift provision in new developments
Join the RSPB Swift Mapper project to report swift nest sites in your area
Support Swift Conservation and local swift groups working on nest site protection