Common Swift Welfare: Nesting Success in 2025

Common swift nesting welfare in 2025 continues to improve as swift brick installation in new buildings becomes more widespread, offsetting losses from building renovation that remains the primary threat.

Key Facts

UK swift populations have declined by 60% since 1994, primarily due to loss of nest sites in buildings
As of 2025, over 150 local authorities require swift bricks in new construction in their planning policies
Swift numbers at monitored sites are stabilising in areas with strong nest box and swift brick programmes
Swift chicks fledge after 5-8 weeks in the nest; the nest site must be undisturbed throughout this period
Swifts scream in chasing parties around nesting buildings in June and July, a welfare indicator of site fidelity

Welfare Considerations

Individual swift welfare centres on the security of their nest site throughout the breeding season. A swift displaced from a long-established nest cannot simply adopt a new site; their extreme site fidelity means displacement causes breeding failure and may deter use of adjacent sites by other birds. The 2025 progress in planning policy requiring swift bricks directly benefits welfare by ensuring newly constructed buildings provide habitat equivalent to the old buildings lost to renovation. Continued advocacy and monitoring are needed to maintain momentum in the face of building renovation that threatens established sites.

What You Can Do

Install RSPCA-approved swift bricks or boxes on your building if you have suitable walls
Contact your local planning authority to ask about swift brick requirements in new construction
Check for swifts before any building work between May and August and seek advice from Swift Conservation
Report swift nesting locations to Swift Conservation and local wildlife groups