00000cam 2200000za 4500 9.855895 CaOODSP 20241203113642 cr ||||||||||| 180427s1986 onca|||#o f00| 0 eng d CaOODSP eng n-cn-on CW69-1/57E-PDF Blokpoel, H., 1938- The ring-billed gull in Ontario [electronic resource] : a review of a new problem species / H. Blokpoel, G.D. Tessier. [Ottawa] : Canadian Wildlife Service, 1986. 34 p. : ill. Occasional paper ; no. 57 Digitized edition from print [produced by Environment and Climate Change Canada]. Issued also in French under title: Le goéland à bec cerclé en Ontario : une nouvelle espèce problème. Errata sheet inside front cover. Includes bibliographical references. "During the period 1976-84 the nesting population of the Ring-billed Gull (Larus delawarensis) in the Great Lakes and Upper St. Lawrence River increased at an average annual growth rate of 11%. In 1984 there were an estimated 700 000 pairs of Ring-bills in that area (about two-thirds in Canada and one-third in the USA). Because Ring-bills are highly adaptable it is likely that their numbers will continue to increase"--Abstract. gccst Birds gccst Population gccst Environmental impact Ring-billed gull Tessier, G. D. Canada. Environment Canada. Canadian Wildlife Service. Le goéland à bec cerclé en Ontario (CaOODSP)9.856578 Occasional paper (Canadian Wildlife Service) no. 57 (CaOODSP)9.504780 PDF 12.62 MB https://publications.gc.ca/collections/collection_2018/eccc/CW69-1-57-eng.pdf