Saker (Falco cherrug)
Measurements: 0.45-0.55cm long; wingspan 1.0-1.3m
Id: Large stocky falcon, second largest after Gyrfalcon; wings rather broad with blunt tips. Adults strongly streaked on the underparts, and whitish head contrasts with mainly dark body.
With their streamlined bodies and fast flight, most falcons are bird catchers; but not the Saker. It feeds predominantly on small mammals, one of only two European falcons to do so (the other is the Common Kestrel). Its favourite prey items are ground-squirrels or susliks (Citellus), which can constitute a major part of the diet, but it also catches gerbils, hamsters and some rabbits, as well as birds up to the size of sandgrouse. Such prey abounds on the steppe and woodland steppe where this bird primarily occurs.
Most food is taken on the ground, although when a Saker does target birds, these can be snatched in mid-air. The usual view of a hunting Saker, though, is of a bird sitting for hours on a prominent perch on a rock or tree, watching for movement below. When something finally shows, the bird drops quickly and silently down, hoping to catch its prey by surprise.
In the breeding season, pairs of Sakers tend either to breed on cliff ledges or on the top of isolated trees. Tree sites are usually 15-20m above ground, and are invariably within the abandoned nests of other birds such as Grey Herons, Ravens or other birds of prey. In recent years, showing welcome adaptability, the Saker has also taken increasingly to using artificial sites, particularly on pylons.
From ‘Birds: A Complete Guide to All British and European Species’, by Dominic Couzens. Published by Collins and reproduced with permission.