July 2011 – vol. 104, issue 7, pp 364–397 Abstract In total, over 12.5 million waterbirds occur in Britain during the winter. Estimates of the numbers of non-breeding waterbirds visiting Britain are important for the birds' conservation, both for status assessments and for the identification and designation of nationally and internationally important sites. This paper collates data from a wide range of sources, principally for the period 2... This article is only available to registered users.To read more, please log in or purchase a subscription.