Blog
The incredible swift
Thursday 13th August 2026
Anne Watson
My husband and I moved into our top floor central London flat about 20 years ago, not realising that we already had lodgers who came and went as they pleased! That summer we couldn’t believe what we were seeing when birds flew up in front of the living room window and disappeared under the roof – swifts!
We watched two pairs of the birds arrive and take up residence in gaps under our eaves and, judging by the wearing on the brickwork, they, and their predecessors, had been visiting for decades. In fact, there could have been swifts nesting here since the place was built over 150 years ago! But they do no damage, leave no mess and are excellent tenants.
Swifts don’t build nests in trees, like robins, or on the outside of buildings like house martins. They use holes and crevices (or special nest boxes if they’ve been put up), returning to the same one year after year after year. If their hole gets blocked up while they’re away, then that nest space is lost, and the birds may well not breed that year. New spaces are increasingly hard to find, and some birds even die trying, relentlessly, to gain access to their faithful nest hole.
The UK’s swift population has fallen by over 70% in the last 50 years as holes are filled in, and because new buildings are tightly sealed up. But we have a little colony and we get to experience swift ‘screaming parties’ doing acrobatics and highspeed fly-bys over and around us on our roof terrace. Humans don’t seem to be on their radar so we stand and watch (and sometimes feel the draught) and they carry on as if we’re not there. It’s incredible to be so close to a wild bird!
Swifts breed in Europe, arriving in late April or early May. Ours usually arrive on 7th May (yes, really!). The chicks hatch – we can hear them cheeping in the nests – but can go into torpor if mum and dad need to spend longer away from the nest to find food.
Swifts are incredible. The adults can fly 100km in a day, round storms and bad weather, catching insects on the wing. They’re the fastest birds in straight flight. They grab nesting materials on the wing, anything that’s floating about in the air. They mate, eat and drink on the wing. They bathe in cloud vapour, and they sleep on the wing, spiralling up into the sky at night on what are called ‘vesper flights’, coming down in exactly the same location. They do the same at dawn. Scientists have found that these flights take them to altitudes of 8,000 feet, and allow them to orientate themselves using the pattern of the stars and light polarisation, recalibrating their inbuilt magnetic compass. They can forecast the weather this way, too, because they can see and feel oncoming weather systems and wind directions.
Outside of the nesting season, swifts never, ever land. A swift on the ground is a dead swift. There are never swifts sitting in trees. Their Latin name is Apus Apus which means ‘footless footless’ because they have very short legs and can’t walk about or perch like other birds. The chicks have to be ready to fly like adults as soon as they leave the nest, because there’s no going back. So they do press-ups to strengthen their wing muscles! Swifts leave the nest by dropping out and down, and then swooping away. So the babies drop, and swoop – and then don’t land again until they are breeding themselves, perhaps two or sometimes even three years later! Once they leave Europe it’s back to Africa until next spring.
Each year the breeding pair arrives first, followed by the ‘bangers’ – the juveniles who aren’t breeding yet but are looking for nest spaces. They scream and clatter against nest holes, while the swifts inside scream back!
We’ve had a few swift adventures over the last 20 years. A swift ended up in our hallway and had to be released back outside. You must never throw a downed swift into the air (drop and swoop, remember?) so picture me standing at the top of a step-ladder, on the edge of a small, and very high up, roof terrace, with my arm up in the air and a swift on my hand, waiting for it to leave. It wasn’t afraid of me, and certainly wasn’t in a rush (my poor arm), but eventually it was off to rejoin its mate. And we’ve had one fly in the door a couple of times, realise its mistake, veer back round and out again – quite a sight when you’re sitting quietly watching the telly!
So next year, keep looking up to see if you can spot these scythe-like wonder birds - although you’ll probably hear them before you can see them. Find a local swift group. Look out for and protect any nest spaces. And even put up some boxes of your own. Using a special swift caller will help attract them, and maybe you can start your own little colony.