Sadly, numbers are in freefall, so Sussex Ornithological Society is marking Swift Awareness Week, which runs from July 3 to 11 this year, by highlighting the simple steps people can take to reverse the dramatic decline.
He said: “For a few lively weeks each year, we share the streets with some very special visitors. They have been called the ‘devil bird’ for their black silhouette and bizarre scream, and more recently the ‘hundred-day bird’, in a nod to their rushed summer here.
“The swift, as it’s properly known, arrives in early May, after wintering in southern Africa, but vanishes again as soon as July and early August. Swift Awareness Week is a chance for us to celebrate this incredible bird and share its story.
“Between their summers here, individual swifts might well spend every waking, and sleeping, moment airborne. In the same way many seabirds touch land only to breed, swifts will be persuaded out of their element only when it’s their time to rear young.
“They are so supremely adapted for life on the wing that they can struggle to get back in the air if they end up grounded and it was once believed they lacked feet.
“Unusually, the swift is one charismatic long-distance migrant which can be seen without a trip to the countryside. Long ago, the swift was a bird which nested in crevices offered by cliffs and old trees, but for hundreds of years they have instead slipped quietly into the eaves of our houses.
“More respectful neighbours than most urbanites, nesting swifts are not only unobtrusive – bolting in and out in a blink – but also mess-free. In fact, many homeowners with nesting swifts would never have guessed the birds are in residence. They leave no droppings outside the nest and the material inside breaks down while they swoop over the savannahs and rainforests of Africa.
“Swifts are often confused with swallows and house martins but belong to an entirely different taxonomic group. In fact, they are close relatives of the hummingbirds.
“They are among the fastest birds in level flight, clocking in at almost 70 miles per hour at full pelt. Their diet is exclusively made up of airborne invertebrates, which they bring to their young in ‘bugballs’ of up to 1,000 insects and floating spiders.
“When the weather turns, they take drastic measures to survive. The young enter a state of torpor, allowing them to live without food for several days while their parents fly around storms and sometimes over seas to forage in calmer skies.
“Once the young drop out of the nest, they are on their own and that first flight might last for many months, so it’s important to get it right.
“Sadly, swift numbers are in freefall. More than half of the UK population was lost between 1995 and 2016, and there is no hint of a recovery yet. Several factors could be driving the decline, including climate change and the continuing crash in insect biomass but one obvious problem is the steady modernisation of building.
“Houses built after about 1960 happen to block swifts from entering, while renovations on older builds can also shut the birds out. After centuries of nesting in our eaves, and with natural sites much scarcer, swifts are now struggling to find somewhere to nest.
“Fortunately, this means we’re able to remedy at least one of the challenges that this enigmatic bird faces. Swift boxes are readily available online and can provide the perfect home for a nesting pair. You just need to find someone able to safely install it using a ladder.
“Specially-designed bricks can be incorporated into new builds, holding the structure not only of the building but supporting the local swift population, too. If you have a say on a building that’s at least 4.5 metres high, with an unobstructed aspect facing away from strong sunlight, why not consider installing a swift box? Even if you’re unable to do so, you can still help swifts by reporting your sightings on the Swift Mapper app, collecting information which will help inform their conservation.
“There’s nothing like a summer evening outside, or in the pub garden, while these loveable banshees scream and wheel overhead. Let’s secure the future of our swifts in Sussex and beyond.”
Swifts pair for life and meet up at the same nest site in the UK each spring.
By reporting where you see nesting swifts, you will help to build a picture of where swift nest sites need to be protected and where it would be best to provide new nest sites. Watch out for groups of swifts flying fast at roof height, often screaming loudly – this means they are breeding nearby.
Swifts nest in holes, so report any swifts you see entering holes in buildings, but do not report swifts flying high in the sky, feeding over water or fields.