Common swifts spend almost their entire lives airborne, but their dependence on old buildings for nesting makes them highly vulnerable to renovation and development.
Swifts are exceptional animals whose entire life is adapted for the air — they cannot walk normally on flat ground. Their dependence on specific hole-nesting sites in old buildings creates a vulnerability to human development that has caused catastrophic population decline. Each swift that loses its nesting site loses the ability to breed for that season, and often abandons the area permanently. Installing swift bricks during renovations and protecting existing colonies during building works costs almost nothing compared to the irreplaceable ecological value these birds provide through insect control and biodiversity.