Rooks are quite easily distinguished from the similar carrion crow, they both have full coverage of black plumage, however, the rook has a pale bill and a bare grey face at the base of their bill. They also have a more cone-shaped head and feathers on their legs which look like a pair of trousers, which no other UK corvids have.
Average Length: 44-46 cm
Average Lifespan: 6 Years
Average Wingspan: 81-99 cm
Similar to other corvids, rooks are not fussy eaters, they will eat almost anything from worms to small mammals, birds, eggs, and carrion.
Rooks are colonial breeders and nest in large colonies known as rookeries, where males can be seen strutting and bowing to impress the females. They can begin nesting as early as late February, both sexes contribute to building a bulky nest made of twigs and lined with grasses and leaves. Often they will repair a previous year's nest and reuse it leading to very large nests forming. They usually lay 3 to 4 eggs, but larger broods have been recorded, which are incubated by the female for 15-16 days while the male provides food. Once hatched the male will continue to provide food while the female broods until the chicks are old enough for the female to aid in the feeding efforts. After 32-34 days the young fledge but require care from the parents for some time after.
While rook populations have decreased since 2000, the causes of this decline are not well understood. Licenced killing of rooks is legal in the UK, however, this alone is unlikely to significantly impact their population. However, when combined with changes in agricultural practices such as the application of pesticides and seed dressings (treating seeds with antibacterial substances before sowing) could be enough to drive the decreases seen.
Don’t view these birds as a pest, welcome them to your garden or land.
Provide clean water throughout the summer in a larger bird bath.
A group of rooks is called a parliament due to the apparent way in which they gather in a circle around one or two individuals who ‘speak’ at length.
BirdLife International (2023) Species factsheet: Corvus frugilegus. Downloaded from http://datazone.birdlife.org/species/factsheet/rook-corvus-frugilegus. Accessed: 25/09/2023.
British Trust for Ornithology (2023) Rook | BTO - British Trust for Ornithology. Available at: https://www.bto.org/understanding-birds/birdfacts/rook. Accessed: 25/09/2023.
Dally, J. M., Clayton, N. S., & Emery, N. J. (2008). Social Influences on Foraging by Rooks (Corvus frugilegus). Behaviour. 145(8): 1101-1124.
Griffin, L. R., & Thomas, C. J. (2000). The spatial distribution and size of rook (Corvus frugilegus) breeding colonies is affected by both the distribution of foraging habitat and by intercolony competition. Proceedings of the Royal Society B: Biological Sciences, 267(1451), 1463–1467. https://doi.org/10.1098/rspb.2000.1165
Kasprzykowski, Z. (2003). Habitat Preferences of Foraging Rooks Corvus frugilegus During the Breeding Period in the Agricultural Landscape of Eastern Poland. Acta Ornithologica, 38(1), 27–31. https://doi.org/10.3161/068.038.0107
Mason, C. F., & Macdonald, S. M. (2004). Distribution of foraging rooks, Corvus frugilegus, and rookeries in a landscape in eastern England dominated by winter cereals. Folia Zoologica. 53(2): 179-188.
RSPB (2023) Rook bird facts: Corvus Frugilegus, The RSPB. Available at: https://www.rspb.org.uk/birds-and-wildlife/wildlife-guides/bird-a-z/rook/. Accessed: 25/09/2023.