No.007 · Birds · Uncommon
Swift
Apus apus
A scythe-winged screamer of summer skies. Swifts eat, sleep and even mate on the wing, coming down only to nest; they spend under four months in Britain.
When to look
May to August, mostly at dawn, day and dusk.
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Time of day
- Dawn
- Day
- Dusk
- Night
- Best time
- Late April/May to early August, in the air at dusk in June–July; the air fills with screaming parties.
- Where in the game
- Millbrook (urban, churchyard, park, canal, farmland and garden)
- Size
- Length 16–17 cm
- Wingspan
- About 45 cm
- Weight
- About 40 g (BTO adult average)
- Lifespan
- Average about 9 years; the oldest ringed bird lived nearly 18 years (Wildlife Trusts, BTO)
- Population
- About 59,000 pairs in the UK (BTO, 2016); down 70% between 1995 and 2024 (BTO)
- Status
- Red (Birds of Conservation Concern 5, 2021); moved up from Amber in 2021
Diet
Airborne insects and spiders, caught in flight; feeds low before rain.
Habitat
Skies over towns and villages; nests under roof tiles, in eaves and swift boxes in old buildings.
Breeding
Nests under eaves in old buildings from late May; 2–3 eggs; chicks fledge after about 5–8 weeks and then stay on the wing.
Field signs
- High, shrill screaming as parties chase round rooftops at dusk
- Dark, crescent-shaped birds with fast, stiff wing-beats; no perching
- Swift boxes and nest holes under old roof tiles
Did you know?
- A Swedish study with tiny trackers found common swifts spend about 10 months of the year on the wing outside the breeding season, and some individuals never landed at all.
- Swifts arrive in the UK from Africa from late April, and most have gone by mid-August to September (BTO).
- Swifts are Red-listed because modern roofs and renovations remove the nooks they nest in; swift bricks built into new homes help.
Moments worth waiting for
- Screaming party
A gang of swifts sweeps round the rooftops at speed, shrieking, then rockets skywards. - Feeding low before rain
Swifts skim low over the canal and playing fields, scooping up insects as the air thickens before a shower.
Photo tip
Photograph them at dusk in June and July when the screaming parties race low over rooftops. Use a fast shutter (1/3000 s), pan smoothly, and pre-focus on the church tower.
Be a good naturalist
Never disturb a nest site under eaves in summer; install swift boxes or bricks in September or October, well after they have gone. Do not use recorded calls to lure them.
The law
All wild birds, their nests and eggs are protected under the Wildlife and Countryside Act 1981; it is an offence to kill, injure or take them or damage an active nest. Swifts return to the same nest site year after year, so blocking it up out of season still harms them.