The common swift, Apus apus, arrives in the Lake District in late April or early May — one of the last summer migrants to reach Britain, travelling from sub-Saharan Africa across the Sahara, the Mediterranean and France before crossing the Channel and continuing north to its breeding sites in the eaves and roof spaces of old buildings across Cumbria.
It leaves again in late July or early August — earlier than the swallow and house martin, which linger into September. The swift's presence in the Lake District is approximately twelve weeks long, concentrated in May, June and July.
In that twelve weeks it is the most audible bird in any Lakeland town.
The behaviour that announces the swift's arrival, and its continued presence through June, is the screaming party — a group of swifts, typically between five and twenty birds, flying at high speed around the rooftops of a town or village, calling constantly with the high, screaming call that is unmistakeable and carries two hundred metres in still air.
Screaming parties occur most reliably in the late evening — from about 8pm until dusk — when the temperature drops slightly and the insects that the swifts have been feeding on all day are concentrated at lower altitudes. A screaming party in the lanes of Ambleside on a June evening, with the birds banking and turning at eye level between the buildings, is one of the most dramatic pieces of wildlife behaviour available in any English town.
In Hawkshead, where the buildings are old and the roof lines have the deep eaves that swifts prefer for nesting, the screaming parties are particularly concentrated.
The swift is not closely related to the swallow or house martin, despite the superficial similarity in silhouette. It is more closely related to hummingbirds. Its feet are so small and weakly developed that it cannot perch in the manner of most birds — when a swift lands it clings to a vertical surface rather than sitting on a horizontal one. A swift found on the ground cannot take off from a flat surface; it must be launched from height.
A swift that has fledged from its nest and left the colony does not land again for approximately two to three years — it eats, drinks, sleeps and mates on the wing. The individual you see screaming over Ambleside in June may not have touched a solid surface since it left its natal colony two or three seasons ago.
Swift populations in Britain have declined by approximately 60% since 1995. The cause is primarily the loss of nesting sites: the renovation and re-roofing of old buildings closes the gaps under eaves and in roof spaces that swifts depend on. Swifts return to the same nest site year after year; when that site is lost the bird has nowhere to go.
Swift bricks — purpose-made nest chambers built into new buildings or inserted into existing ones — are increasingly required by planning authorities for new developments. Several buildings in the Lake District now have swift bricks installed, and the colonies using them are monitored by local wildlife groups.
The best swift watching in the Lake District is in the villages and towns with old buildings: Ambleside, Hawkshead, Grasmere, Keswick. Arrive in the early evening, find a place with a good view of the rooflines, and wait. If the swifts are present the screaming parties are impossible to miss.
Above the fells, swifts fly higher than swallows and martins — often at two hundred metres or more — and can be identified by the crescent wing shape and the complete absence of any wing-beat pause. The swift moves through the air as though cast rather than flown.
Wildlife, including migratory birds, is covered on all our tours throughout the season. See all tours.