March 1977 – vol. 70, issue 3, pp 127–128 Interchange between Gannet colonies The paper by M. S. Cullen and R. Pratt (Brit. Birds 69: 88-90) added to the now considerable evidence that relatively massive increases—and sometimes substantial decreases— in the numbers of nest- or site-owning Gannets Sula bassana occur at many gannetries in successive years. I have discussed the details in The Sulidae: Gannets and Boobies (in press), b... This article is only available to registered users.To read more, please log in or purchase a subscription.