“And here they are, here they are again!” Ted Hughes thrilled to the swifts when they returned to these shores in May. These are the first birds in a series of waves of swifts, arriving at different times depending on their age.

Swifts spend most of their lives soaring high in the sky, only ever landing to nest. They are easy to spot as they look like an arrow whirling through the sky, and often fly in groups. Originally, they would have nested in trees or cliffs but now prefer the roofs of old buildings like churches. Swifts spend the winter in Africa but travel to Britain every year in April and May.

They feast on small flying insects by catching them in flight. Insects collect in a special pouch at the back of the swift's throat, where they are bound together by saliva until they form a kind of pellet known as a bolus, which can be regurgitated and fed to chicks. One single bolus can contain over 300 insects, with some holding over 1,000!

Aerial life

The swifts you may see in spring have been flying without cease ever since the moment they launched into the air from the safe, dark nest in which they hatched. From there they straightaway headed south for Africa: snapping up airborne insects, sipping water from lakes on the wing, preening their feathers in elegant aerial manoeuvres and spiralling up into the sky at dusk to sleep and orient themselves. Flying is simply what a swift does, all of the time, unless grounded by misfortune - most likely in the shape of persistent, torrential rain. However, their return to the part of the world in which they hatched is purposeful.

They come to seek a nest and a mate, and to establish their place within the loose, colonial territories that swifts form during the breeding season. Finding a nesting hole takes time but they have an instinct for suitable places and are often attracted by calls from their own kind. Swifts prefer to nest high up, under the eaves of buildings or in crevices in the masonry, searching for an entrance hole to a hidden space where they can make their dish-like nest of feathers, tree seeds and other materials blown up into the air and glued together with saliva.

How to identify swifts

The swift is dark brown all over, often appearing black against the sky, with a small, pale patch on its throat. They're larger than swallows and martins, with long curving wings that make them look a bit like a boomerang when in the air. Swifts are very sociable and can often be spotted in groups wheeling over roofs and calling to each other with high-pitched screams. Unlike swallows and martins, swifts are almost never seen perching. They spend most of their lives flying – even sleeping, eating and drinking on the wing – only ever landing to nest. 

Key features to tell a swift from a swallow or martin are the dark underside (swallows and martins have pale bellies), the proportionately longer wings and the screaming call

What you can do to help

From Saturday 29 June to Sunday 7 July 2024 it's Swift Awareness Week. Could you help these incredible birds?

Protecting existing nest holes is the best thing you can do for swifts as they are very site faithful. If carrying out roof renovation or insulation during the summer, ensure that access holes are not blocked by scaffolding and that they’re retained for the future.

Installing a swift box or two, at least five metres high, is a great way to help swifts but it can take time for the birds to find them. Playing swift calls can speed things up. If you’re thinking of buying a newly-built house, ask your builder to incorporate swift bricks.

Help swifts find food by gardening in a wildlife-friendly way. Insects from your garden may spiral into the air and be snapped up the birds.