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Snowy-crowned Tern - BirdForum Opus

Photo by Rick and Elis
South Brazil, 9 June 2011

Alternative name: Trudeau's Tern

Sterna trudeaui


Distinctive medium sized white bodied tern with gray mantle. Crown white in all plumages. Ear patches black in breeding season, gray in non-breeding. Bill mostly yellow in breeding plumage but dark with a yellow tip in non-breeding.


South America: found in lagoons and marshes of south-eastern Brazil and Uruguay to Patagonia. Type specimen alleged to have been collected at Cape May, New Jersey. Probably incorrect.


This is a monotypic species[1].


Swamps, shallow seas, and intertidal marshes.


Plunge dives for fish. Breeding poorly known. Colonial, often in colonies of Brown-hooded Gulls. Builds an anchored floating nest.


  1. Clements, JF. 2011. The Clements Checklist of Birds of the World. 6th ed., with updates to August 2011. Ithaca: Cornell Univ. Press. ISBN 978-0801445019. Spreadsheet available at http://www.birds.cornell.edu/clementschecklist/downloadable-clements-checklist
  2. Gochfeld, M., J. Burger, and E. F. J. Garcia (2020). Snowy-crowned Tern (Sterna trudeaui), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.truter.01

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