For me, the return of swifts in summer is one of the highlights of the year. They're so evocative of evenings sitting outside, when you can listen to them screeching overhead, tumbling over each other in the sky.
Swifts are often confused with hirundines – the group that contains swallows and house martins – and it’s easy to see why as they do look and behave similarly. But they are not closely related at all, and in fact the closest relative of swifts are hummingbirds! You can tell swifts apart from swallows and house martins by their sickle-shaped wings and their screeching call. Swallows have long tail feathers and a white underside, and house martins have a noticeable white patch on their rump. Swift behaviour is fascinating, they only stop flying to breed, and they sleep, eat and mate on the wing.