Each year I hear them a while before I see them. At first the hearing is subliminal. Their signature screeching insinuates itself as I am occupied with something else; a conversation perhaps, or a book. But the moment I become conscious of their presence I look up. And there they are, Africa-black boomerangs in silhouette, flicking and diving against an ultramarine sky. The swifts have returned. Earth's orbit has cranked full circle and the final piece of summer's jigsaw is in place. The swifts are back, screaming through eaves and gnat-crammed alleys. I am a year older and all is right with the world.
The last to arrive, the first to leave, we can almost set our watches by them. May Day or the day after, never much later than that, whatever the weather and whichever way the prevailing winds are blowing. We have to make the most of them for they are gone again by mid August. I was once astonished to see a lone straggler in the Edinburgh skies on the first of September.
There are some extraordinary fancies told about swifts, the most celebrated being that they have no feet (their taxonomic name Apus apus lending tautological credence to the myth) and that, if grounded, they are doomed. For a bird so intimately associated with human habitation it is remarkable how little we still understand them. They are aerial aliens in our earthbound towns. There is something delightfully otherworldly about them with 'Their mole-dark labouring, Their lunatic limber scramming frenzy And their whirling blades' as Ted Hughes memorably depicted them.
Once, while touring in Rioja country on one of the hottest days I can ever remember, I came across a solitary swift apparently crash landed in a tree. I had no camera with me and they have never been within range since. However I can testify to it being equipped with a full complement of feet, four toes apiece. But you don't have to believe me.