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Résumé :
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The populations of colonial waterbirds (gulls, terns and other seabirds, and herons) have been accurately censused only in restricted regions of the earth. The continental or worldwide review (Cramp & Simmons, 1977 and 1983; Croxall et al., 1984; Cramp, 1985) include sound data on populations of colonial waterbirds, which are limited to Northern and Central Europe, the coasts of the United States of America and of Canada, and a few other countries, e.g. South Africa. Elsewhere, the data are either incomplete (e.g. the Mediterranean countries) or merely qualitative (most tropical and southern regions).
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