The sky is full of swifts. Okay not full of them, in truth there’s only a handful, but like the voices in my head when I wake nightly at 3am, they sound legion.

The birds are getting ready to leave, heading back to Africa. Their flight formation has grown more disciplined and precise in the last few days, which means it’s high summer, which in the UK translates to almost over. Meteorologists will tell you that September is officially the beginning of autumn, but everyone here knows it’s August.

Swifts vanish from our skies about the same time as ‘back to school’ sections start appearing in supermarkets. Adept at navigation by the stars and Earth’s magnetic field, swifts have no need of compasses and protractors. 

The swifts’ departure leaves me melancholy. Maybe you’ve heard songs of mine —most things do — but it’s hard not to read omens into the flight of these birds. All birds. They know things before we do, their calendar is different, their sooth-saying more accurate. Every year there are fewer swifts. The reasons; not enough insects, vanishing nesting sites, the general and all pervasive effects of climate disaster. Part of me is ready for the summer they don’t make it back. Or I don’t.

When I lived in Somerset — my first attempt at living out of the city — that spring we saw swifts returning to their familiar nesting sites under the eves of our hamstone cottage. They didn’t appear to land as much fly full speed into the wall, then scramble paratrooper-like into the shadows. At night we could hear them chittering quietly on their amateurish nests, then in the morning the brush of their scimitar wings on the cottage as they left to hunt. Soft blades being honed. That first summer, the morning after they left, their absence woke me.

I grew up, for a time, with a bird watching father. From quizzes on car journeys I came to learn facts about many birds. The bee hummingbird, the Artic tern. But I always liked the story of the swift. Life lived entirely on the wing. Never landing except to lay eggs. Even sleeping in the sky. At night, above the bats, and far above the quartering barn owls, they’ll be there. Dreaming themselves afloat. 

This year, despite knowing the house I now live in isn’t suitable, I installed swift boxes. Starter homes specifically designed for these picky birds . The building is too low to the ground, sofits beneath the guttering block access to the eves. There’s no safe flight path free from walls, fences, trees or domesticated predators for the birds to navigate safely. But I did it anyway. Unfounded hope. Because this is how I like to live now, given the state of everything. And because you never know.

I rescued a swift from the jaws of a cat once, a long time ago. For birds that spend their entire lives in motion, those brief minutes trapped stationary in the maw of a tabby must have felt like an eternity. Life flashing before its dark brown eyes. The continents mapped, the oceans charted, the acrobatic sex. These birds — that if you add up all the miles they fly in a lifetime — could fly to the moon and back,  eight times.

I held the almost weightless bird for a few seconds while it recovered, imagining its heartbeat, its breath, that very first nest in the Sea of Tranquility. Then, feeling it struggle, I opened my palms and it was gone. I held on to the feeling longer than I held on to the swift.

I’m going to do that again when they leave this week, or next. I can’t make them stay, and I can’t guarantee they’ll be back, but I’ll hold on to the feeling. And I’ll put up more swift boxes, because this is how I like to live now. And because you never know.