Species of the Month: Rook Corvus frugilegus (April 2025)
Rooks Corvus frugilegus belong to the Corvidae family and are the most gregarious of our resident crow species in the breeding season. They can be most easily distinguished from other black corvids by the grey-white skin at the base of their long, pointed beak, which gives the head a somewhat cone-shaped appearance.
Their colonial nesting sites – rookeries – are most easily noticed in spring before the leaves appear on the trees; now is the best time to record these breeding colonies by counting the nests. Nesting colonies are often noisy; the constant ‘discussions’ between neighbours is part of the daily soundtrack at the SWSEIC office during the spring and early summer. Whilst disliked by many, for SWSEIC staff the absence of the raucous chatter was a missing sign of spring during the 2020 lockdown when we were working from home. Indeed Peter Cushing, the famed star of many Hammer horror films, apparently chose the sound of cawing Rooks as one of his Desert Island Discs!
Rooks primarily feed in agricultural land, where they eat invertebrates such as earthworms, leatherjackets (the larvae of craneflies) and beetles. They will also take grains and fruits when available. In the breeding season their feeding sites are usually within a kilometre or two of the rookery. Their resourceful nature can bring them into conflict with agriculture, and although they sometimes cause significant local damage (e.g. to newly-sown crops), in most cases they are not troublesome neighbours.
In the UK, Rooks are Amber listed under latest Birds of Conservation Concern review, with monitoring indicating a fall in numbers of 23% in the last 25 or so years. Rooks have a very long history of local monitoring in Dumfriesshire, with surveys in Dumfriesshire dating back to 1908. Details of these surveys can be found in the transactions of the Dumfriesshire and Galloway Natural History and Antiquarian Society. An interesting summary of Rooks in Ayrshire is available on the Ayrshire Birding website.
Mark Pollitt
SWSEIC Manager