In 2022, thanks to the help of many volunteers, over 450 survey squares were covered. However, we need more squares surveyed in 2023 for a robust population estimate to be calculated. We are repeating the method adopted by the 1996 UK survey, with observers counting the number of nests in rookeries on a single visit between 20 March and 20 April, before the leaves fully emerge. If it is a late spring, the survey can be extended to 30 April. The definition of a rookery is two or more nests in close proximity, but over 100m from another cluster of nests. It is not essential, but highly desirable, that the tree species in which the rookery is located should be identified too, especially as Ash (Fraxinus excelsior) is predicted to become far less available over the coming decades. Since identifying broadleaf trees to species level can be challenging before leaves unfurl, advice on useful ID guidance will be given to volunteers who require it.

Sign up for your 2023 tetrads here – the page contains links to all the necessary documents and details.