Sassy and sociable, the swifts are back in town

Kendal, Lake District Every year they fly 5,000 miles to breed in the exact same crack or crevice in the exact same building

In their brief sojourn here, swifts wreak high-pitched havoc - they are all daredevil velocity and sassy sociability. Since Roman times at least, these urban Apodidae have exploited humankind's structures. They are nest site faithful, returning every year to breed in the exact same crack or crevice in the exact same building after their 5,000-mile migration from Africa.

But according to the RSPB, over a third of the UK's swifts have been lost in 22 years, in no small part because of habitat loss. Re-roofing or re-pointing old stone buildings can unwittingly lock swifts out; they may return from their long-haul trip to find their homes boarded up and, for that season at least, breeding will not take place.