This article first appeared in Countryside La Vie magazine.
In his single verse poem Thaw, Edward Thomas makes two accurate observations about the Rook: its habit of breeding early in the year, and, at the time he was writing in the early twentieth century, its preference for nesting in elms. Mature elms are sadly long gone from the Leicestershire and Rutland landscape, victims of Dutch Elm Disease in the 1970s, but the Rooks are still here. And in contrast to many farmland birds, they are at least maintaining and possibly even increasing their numbers.
Nesting colonially in conspicuous rookeries, the Rook is a straightforward species to count in the breeding season. The last full survey by the Leicestershire and Rutland Ornithological Society found 12,261 pairs of Rooks nesting in 421 rookeries. This gives an average of around 30 nests per rookery, but the largest contained up to 200 nests. As Thomas observed, Rooks start nesting before most other birds, returning to refurbish their nests over the winter, and laying eggs as early as the end of February.
A rookery in early spring is a busy place, full of birds coming and going with sticks for their nests and all constantly calling with that familiar deep ‘craa’ which is so much a part of the British countryside. Easily dismissed as just another black bird looking very much like a crow, close up in sunshine a Rook is transformed. The ‘black’ feathers can be seen to be glossed with electric blues and purples, and the large pale grey bill surrounded by bare skin at the base is quite unlike that of its relation the Carrion Crow.
Not surprisingly for such a familiar bird which nests close to human settlements, the Rook often features in folklore. The sudden desertion of a rookery was said to be bad luck for the landowner, and it was once believed that the birds can foretell rain. One of the most intriguing myths is the idea that Rooks hold ‘parliaments’, sitting in judgement of their peers and handing out harsh punishments for wrongdoers. However, this is most likely to be a misinterpretation of normal territorial behaviour, which will sometimes escalate into violence, even among colonially nesting birds such as the Rook.
The crow family, of which the Rook is a member, often gets a bad press. Some of this may be justified; it can be distressing to watch a pair of Magpies or crows taking all the young from the nest of a garden bird, but by comparison the Rook is fairly benign. Most of its diet consists of worms and various insect larvae, including pests such as wireworms and leatherjackets. At sowing time though, they can be less welcome on arable farms, as they eat newly sown cereals. As a result the Rook has long been regarded as a pest, and many are still shot, although even on farmers’ tables Rook pie is a less common dish than it once was!