December 1975 – vol. 68, issue 12, pp 507–513 Following the national census of coastal seabird colonies (Operation Seafarer) in 1969-70, a census has been carried out annually, as a population monitoring scheme, at about 50 colonies throughout Britain and Ireland. The species counted at these sites include the Razorbill Alca torda and the Guillemot Uria aalge. At most colonies the annual census is obtained from a single count, although counts... This article is only available to registered users.To read more, please log in or purchase a subscription.