Common swifts have declined sharply in the UK as old buildings are renovated, destroying nest sites - conservation efforts focus on creating artificial swift bricks and towers.
Swift welfare is critically tied to nest site availability. As colonial nesting birds that return to the same site year after year, swift pairs suffer directly when their nest sites are lost to renovation - arriving birds circle their old site repeatedly in evident distress before departing. Providing replacement nest sites through swift bricks, towers and boxes is a direct welfare and conservation intervention. Swift societies provide free advice to householders and developers. Planning conditions requiring swift bricks in new buildings are increasingly being adopted by progressive local authorities.