Common swifts have declined by over 60% in the UK since 1995, largely due to loss of nesting opportunities in buildings as renovation seals up eaves and gaps. Providing swift nesting sites is a direct conservation and welfare action.
Swifts that cannot find nest sites may be unable to breed, causing population decline. Adults without nest sites remain physiologically capable of breeding but cannot contribute to reproduction, representing a welfare and conservation loss. Newly fledged swifts that fall to the ground are completely unable to take off from flat surfaces and will die without human rescue — they should be placed on an elevated surface and if unable to fly should be taken to a wildlife rehabilitator. The mass loss of nesting opportunities through building renovation is a human-caused welfare and conservation emergency with straightforward mitigations.