Scientific name: Apus apus
Conservation status: Classified in the UK as Red under the Birds of Conservation Concern 5: the Red List for Birds (2021). Protected by The Wildlife and Countryside Act 1981
There are around 113 Swift species worldwide, eight of which may appear in the UK. But our familiar summer visitors are the Common Swift, Apus apus.
The average lifespan of a Swift is nine years, reaching breeding maturity at around four years old. Estimates of the oldest recorded Swift range from 18 – 21 years old.
Swifts pair for life and will actually form their pair bonds from as early as one year old when the pair will seek out their nest site that they return to year after year, but they are unlikely to nest successfully for another few years.
Swifts fledge at around six weeks old and are immediately independent of their parents, beginning their migration to Africa only a few days after leaving the nest.
To prepare themselves and build up their wing muscles, at 3-4 weeks old while still in the nest, young Swifts will do “press-ups” by pushing down on their wings to lift their bodies off the ground.
Once-fledged Swifts spend most of their lives in the air, they even drink, mate and sleep while still flying. The only time they land is to nest.
Every year they make the 6,800-mile round trip from their winter feeding grounds in Africa to their breeding grounds in Britain, arriving in our skies during April and May, and leaving as the summer ends in August.
Swifts are voracious hunters, specialised in catching flying insects and drifting spiders.
They collect insects in a special pouch at the back of the throat binding them together with salvia into a pellet known as a bolus that weighs just over a gram but can contain anywhere from 300 to 1,000 insects. They regurgitate the bolus to feed their chicks.
Originally Swifts would have nested in crevices in trees or cliffs but they now almost exclusively nest in the roofs of buildings, making them a feature of urban wildlife.
They are dedicated homeowners, constructing their nests using a variety of materials they find on the wing, including feathers, paper, straw, and seeds, which are all cemented together with their salvia. They will return to the same nest every year and make repairs and renovations before laying their eggs.
As old buildings get renovated, better insulated or replaced with new builds, Swift nest sites are fast disappearing. This, in part, has resulted in Swifts being added to the Red List in the 2021 UK Conservation Status Report which recognises their steep decline in breeding population and range. This is why Ealing Wildlife Group’s Swift Project is so important.
Anything you can do from installing a swift box, recording nesting Swifts on RSPB’s Swift mapper, raising awareness with your neighbours or campaigning for planning legislation to include Swift bricks in all new builds, everything counts toward supporting this impressive and iconic creature.
This species focus was written by EWGs Assistant Secretary and Newsletter Editor, Sarah Murphy.