May 1971 – vol. 64, issue 5–238 Birds of Estuaries Enquiry This joint project of the British Trust for Ornithology and the Royal Society for the Protection of Birds was outlined in 'News and comment' last year (Brit. Birds, 63: 183). The first report of the pilot survey, covering the period August 1969 to April 1970, was published in April this year. The 24-page document covers briefly the main wildfowl and gull concentrations no... This article is only available to subscribed users.To read more, please log in or purchase a subscription.