WeBS Annual Report - Numbers & Trends

The Wetland Bird Survey (WeBS) is a joint scheme of the British Trust for Ornithology (BTO), Royal Society for the Protection of Birds (RSPB) and Joint Nature Conservation Committee (JNCC), in association with Wildfowl & Wetlands Trust (WWT).

The principal aims of the scheme 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. Following publication of latest waterbird population estimates (Wetlands International 2012), revised thresholds for listing sites of international importance are used in this report. Where applicable, interpretation of WeBS results is placed in the context of trends from other countries in the East Atlantic flyway.