Nature Notes

ROOKS KEEP extremely long hours. Of all diurnal birds they are the earliest on the wing, and also the last to go to roost. At this time of year their day begins with a great gathering or convocation: hundreds of them - maybe thousands, even - swarm into the air at first light and for several minutes fly round in an enormous cloud, giving off a terrific clamour and gradually gaining height, before dispersing into smaller but still large groups.

What are they up to, mustering like that and making such a racket? It is as though they are getting up steam and nerving themselves to go about the day's business.

Rooks can be distinguished from all-black carrion crows by the fact that they have bare, grey-white faces, and that they move around in flocks, rather than singly or in pairs. They feed on fields, eating seeds and other vegetable matter, as well as earthworms and a useful number of insects that are harmful to agriculture. Given the chance, they also eat carrion and the eggs of songbirds.

In the evening, rooks stay on the ground until it is almost dark, as if they need to forage for every available minute. This habit is often their undoing, for as dusk thickens foxes come out on the prowl, and many a rook furnishes Reynard with a good dinner.