Kestrels are birds of the town as well as the country, and in June it is not uncommon to hear a great deal of loud calling coming down from the roofs of buildings where they have nested. The parents, and the young when they get bigger, all make loud, shrill “kee-kee-kee” cries. A family of them delighted or enraged the patients some years ago when they nested on the old, red-brick University College Hospital in London. In the country they often nest on cliff ledges or on old, flattened crows’ nests.
But they are best known for the marvellous way they hover over fields, keeping their heads motionless and their eyes fixed on one patch of ground, even if they are being buffeted by the wind. They look forwards, and if they see a vole or even a beetle moving, they swiftly glide down to pick it up. Voles are their preferred food, and it is the abundance of voles on overgrown motorway edges that explains why one so frequently sees kestrels hovering there. The only part of Britain where kestrels are hardly seen is Shetland, and that’s because there are no voles there.
They also catch small birds to some extent, but they rarely chase them in the air, as sparrowhawks or hobbies do. In fact, small birds do not seem to be frightened of them except when they see them overhead. Recently I watched a kestrel sitting on a telephone wire, with a greenfinch perched only a couple of yards along from it, singing away lustily.
They are beautiful birds, with speckled orange backs and speckled undersides. There’s no problem, of course, in telling them from sparrowhawks when they are hovering, but the two species can also be told apart in the air by their wings. The kestrel’s are long and pointed, while the sparrowhawk’s are stubby and round-ended. It is also fairly easy to tell the male kestrel from the female. He is smaller, and has a greyish blue head. Also, the female has a noticeably barred tail, whereas the male’s tail is plain blue with a black tip. So even if you only glimpse the tail as a kestrel flies away, you know which sex it is.