WILD BRISTOL

Pour yourself a beer and watch these scythe-winged ‘devil birds’ tear recklessly around the rooftops like boy-racers on the ring road

The birds of summer

While we’ve been locked away for the past few months, it’s been business as usual for the city’s swifts, says Pete Dommett

Has the storm passed? It’s hard to tell: the bruised evening sky still glowers forebodingly. But rather than reach for my raincoat, I pour myself another beer and watch the swifts. A shrieking gang of these scythewinged creatures tears recklessly around the rooftops like boy-racers on the ring road. Devil birds, they were once called on account of those demonic screams – one of the summer’s most dramatic sounds.

Swifts begin arriving in late April and early May, having travelled 6,000 miles or more from their wintering areas in sub-equatorial Africa. That’s nothing for this bird: an adult swift might clock up 1½ million miles in its lifetime. In fact, no other species spends more time in the air. A swift feeds, drinks, sleeps and even mates on the wing, and only comes down to earth to nest.

In the breeding season, many swifts become urban birds. They collect in colonies in the pre-war-built parts of our towns and cities to nest under loose roof tiles and beneath weather-beaten eaves. Worryingly, these nest sites are being rapidly lost as older buildings are renovated and cavities blocked up; modern houses don’t offer suitable alternatives. As a result, some swifts return in spring to discover their usual nesting places are no more. It’s one reason why Britain’s breeding population has halved over the last 25 years.

Bristol has a number of small, loosely connected colonies scattered across the city, with hot-spots in Redland, Cotham, Fishponds, Hartcliffe and Withywood. In Stoke Bishop, Mark and Jane Glanville have turned their 1920s semi into a swift megalopolis, with 25 homebuilt nest-boxes surrounding their house. Mark tells me that their avian lodgers arrive at this des-res in three distinct waves.

“The first swifts to appear are the breeders. They already have a nest-box, which they used last year, so once they’ve paired up, they’re good to go,” he says. “Then come the bangers.”

Bangers? “That’s what we call the two-year-old birds,” Mark explains. “These arrive at the end of May and beginning of June to bagsy a box for next season. They bang their wings against a nestbox to see if it’s already occupied. If it’s free, they’ll build a nest, but don’t actually breed in it until the following year.”

“The last swifts to visit are the roamers in mid-July,” he adds. “These are young birds, the ones that fledged the previous summer. They’re just sussing out the various colonies in the area to work out which one to join next year.”

After a poor breeding season last year, Mark and Jane are hoping that 2020 will be more successful. So far, it’s looking good – this summer, ‘Swift House’ is home to 15 pairs of breeders which could raise more than 30 chicks between them.

Mark has honed his nest-box design, since making the first one 15 years ago, by carefully observing the swifts’ behaviour to work out exactly what they need. And he’s spent the lockdown busily replying to the many emails he receives from people around the country, and further afield, asking for advice on how to make their homes more hospitable to these birds.

But all too soon the city’s swifts will be gone. In August, they’ll be carving a sky-path back to Africa on wings of curved steel. Their summer is nearly over, while ours seems to be only just beginning –better enjoy them while we can. “In the evening, there’s nothing nicer than just sitting in the garden and watching our swifts,” Jane says. “It’s the perfect way to end the day.”

I’ll raise a glass to that. ■