Songbird Saturday: Swift

Swift screaming, Montgomeryshire

Swift screaming at home of John and Lesley Cookson, Montgomeryshire; (c) Martin Neil

Whether you’re taking a stroll through town, or hiking through fields and farmland, if you hear the air above you filled with a haunting, high-pitched screaming, chances are it’s one of our most eagerly awaited summer visitors: the Swift

Often heard before they are seen, Swifts migrate to the UK from Africa in late April each year, with most arriving in May – to considerable fanfare from wildlife-lovers. They’re only here a few months, to breed and raise their young, before they return to African countries such as Kenya, Tanzania and Uganda in August.

As soon as they get to the UK, these masters of the sky waste no time in setting to work on the serious business of mating and nesting. The use their screams to communicate their location to other Swifts, to find existing pairs – as the Swift mates for life – or to attract a new partner. Swifts are social birds and their calling is often done in large groups or ‘screaming parties’ where it helps keep the group together and defend their territories from other swifts or predators.

A Swift’s call is one of the easiest ways to identify it, especially when these birds are actively flying overhead. These aerial birds, who feed, sleep and even mate on the wing also call from the air. They typically give loud, high-pitched, piercing screams that sounds like “sreee-sreee’ and carry a long distance through the air.

These insect-eaters are most vocal on warm, dry, and sunny days, rarely calling when it is wet and windy. Look for them flying high over the rooftops in towns and villages, where they tend to nest. The best times of day to hear them are around dawn, for the first few hours of light, and at dusk, until it gets dark. These are when the birds are most socially active and returning to or defending their nest sites.

Once you hear them, Swifts can be identified by their long pointed wings held in a sickle shape, their dark brown colour which looks black against the sky, their blunt, bullet-shaped head and their short, forked tail. Depending on the setting, Swifts might be seen flying near Swallows or House Martins, but if you look closely you can tell them apart from these members of the hirundine family by the lack of white on their body, their narrower wings, their larger size and their more direct, slicing flight.

Sadly, both their screaming and their wheeling flight are much rarer than they used to be and disappearing from some areas entirely. Data from conservations organisations such as British Trust for Ornithology (BTO) show their numbers have plummeted by 70% in the last 30 years, adding them firmly to the UK’s red list. A big part of this decline is fast-disappearing Swift nest sites. The birds make their homes in buildings like houses and churches, where they squeeze through tiny crevices to nest in roofs. However, many newer buildings do not have these holes and older buildings are frequently renovated, their soffit gaps closed up.

We are lucky in Montgomeryshire to still see and hear these incredible birds, but they need our help and adding a wooden swift box to your home and joining campaigns to get swift bricks added to all new housing developments help provide the nesting sites these birds desperately need.

In fact, this Songbird Saturday audio of Swifts screaming was recorded (by MWT volunteer Martin Neil, like the rest of this series) at Great Hope Farm near Leighton where John and Lesley Cookson have spent years perfecting swift nest box designs with remarkable success – an inspiration to Swift-lovers everywhere!