The principal aims of the Wetland Bird Survey are to identify population sizes, determine trends in numbers and distribution, and identify important sites for non-breeding waterbirds in the UK. WeBS Core Counts are made annually at approximately 2,000 wetland sites of all habitats; estuaries and large still waters predominate. Monthly coordinated counts are made mostly by volunteers, principally from September to March, with fewer observations during summer months. Data from other sources, e.g. roost counts of geese, are included where relevant. This report presents total numbers counted for all species in the most recent year in Great Britain and Northern Ireland. Annual indices are provided for the more numerous species, as are monthly indices showing relative abundance during the winter.
