THE Victorians called them ‘Devil Birds’, but their association with all things evil goes back centuries, due to their screeching cries, dark colouration and scythed-shaped wings.

Today we know them as swifts and they return to us from Africa in May, to breed. Like swallows and house martins, swifts were designed for life on the wing, but their aerial abilities go way beyond that of any other bird.

Swifts eat, sleep and even mate on the wing. On summer evenings they can be seen circling the skies, climbing higher and higher, up to 10,000 feet, before slowly descending through the night, navigating their course, allowing for variation in wind speed and direction automatically – all while asleep. Swifts lay two or three eggs in small nests of grasses, leaves and feathers, stuck together with the bird’s saliva.

They pair for life and both parents feed the young, collecting insects in their huge gaping mouths. The young leave the nest at six weeks and remain airborne for two years while they mature into adults – and they can live as long as 18 years.

They have the longest wing to body ratio of any bird and their feet are designed for clinging to vertical surfaces rather than walking. This means that if a swift is grounded, it cannot take off again unaided.

Swifts are related to humming birds and watching them displaying their aerial ability makes it easy to see why. Swifts truly are remarkable birds and well worth looking out for this summer.

LB Loxley