Urban Swift Conservation and Welfare

Common swifts spend almost their entire lives airborne but depend on buildings for nesting. Their welfare is directly threatened by building renovation that destroys nest sites.

Key Facts

Common swifts spend up to 10 months of the year continuously airborne, landing only to breed; they are among the most aerial of all bird species
Swift populations in the UK have declined by approximately 60% since the 1990s; loss of nest sites through building renovation is a primary driver
Swifts return to the same nest sites annually for up to 20 years and show strong fidelity to natal colonies — losing a nest site is not recoverable by moving
Swift bricks and nest boxes can provide equivalent nest sites to natural cavities; planning requirements in some UK councils now mandate swift provision in new builds
Renovation of older buildings without swift nest protection causes immediate welfare harm — nesting birds may be sealed in or eggs and chicks abandoned

Welfare Considerations

Swift welfare is almost entirely determined by nest site availability. These extraordinary birds spend most of their lives in perfect freedom in the air but are utterly dependent on a handful of centimetres of cavity in a building wall for their annual reproduction. The loss of a nest site through building renovation — particularly if done during the breeding season when adults or chicks are present — causes direct welfare harm and population-level decline. Swifts that lose nest sites cannot easily find alternatives: they return to where they were born and where they have bred before, and if that site is gone they may fail to breed entirely. Legislative protection for swift nest sites during renovation, mandatory swift brick provision in new builds, and public education about swift colony identification are the most important welfare interventions for this species.

What You Can Do

Check for swift nest sites before undertaking building renovation and delay work until after August when young have fledged
Install swift bricks or nest boxes on south or east-facing walls of buildings to replace lost natural cavities
Advocate for local planning authorities to require swift nest provision in new builds and renovations
Record swift colonies in your area using the RSPB swift mapper to build evidence for nest site protection
Support local swift groups that monitor colonies and advocate for nest site preservation during development