The aim of this national census is to collect annual nest counts of Grey Herons from as many sites as possible in the United Kingdom. The Heronries Census began in 1928 and is the longest-running breeding season monitoring scheme in the world. Volunteer observers make counts of apparently occupied nests at heron colonies each year. Changes in the numbers of nests, especially over periods of several years, are a clear measure of the population's trend. In recent seasons, observers have also counted the nests of Little Egrets which are now appearing in a number of southern English heronries.
For more information, go to Grey Heron monitoring pages of the BTO website.
If you would like to help with heron nest counting, or have any information on breeding sites or new possible breeding sites, then please contact Brian Sharkey (see the Scientific Committee pages for address details).