Rooks are busy nest building at this time of year and the Herts Bird Club is once again asking submission of Rookery nest counts in Hertfordshire in 2026.
In 2025, 228 Rookeries with 4338 nests were found, a big increase on the 2024 totals as a result of better observer coverage. Rooks have been surveyed for a long period in Hertfordshire going back to a complete survey in 1960/61 where 521 Rookeries with 15739 nests were found (Sage & Nau, 1963). Numbers declined until the 1990's, but appear to be stable since, with a loss of Rookeries in the south of the county and trend towards more but smaller Rookeries (Knight, Herts Bird Report 2021).
There are two ways to submit rookery counts. Records for existing rookeries can be added to the live Google Sheet here, where you can see the counts for other rookeries in 2026. Alternatively please submit your records to the Herts Bird Club website here including a nest count and six-figure grid reference. Mobile applications such as ‘OS Maps’ can be useful for calculating your grid reference in the field. A count of the nests that are active is not necessary, just the number of complete nests, provided the rookery as a whole is active.
For any questions about the Rookery survey, please contact Graham Knight here
