Charrán coroniblanco

The snowy-crowned tern (Sterna trudeaui), also known as Trudeau's tern, is a species of bird in subfamily Sterninae of the family Laridae, the gulls, terns, and skimmers. It is native to Argentina, Brazil, Chile, Uruguay, and possibly Paraguay, and also vagrant in Peru and the Falkland Islands. == Taxonomy and systematics == Some genetic data indicate that the snowy-crowned tern and several other closely related terns belong in a genus separate from Sterna. At the least, the snowy-crowned and Forster's tern (S. forsteri) are sister species. The snowy-crowned tern is monotypic. The snowy-crowned tern was first described by the American ornithologist John James Audubon in 1838. He had been sent a specimen by his friend Dr. James de Berty Trudeau (1817–1887) of Louisiana, who had reportedly found several of the terns at Great Egg Harbor Bay, New Jersey. Audubon named the bird in his honor. == Description == The snowy-crowned tern is 28 to 35 cm (11 to 14 in) long with a wingspan of 76 to 78 cm (30 to 31 in) and weighs 146 to 160 g (5.1 to 5.6 oz). It has a rather blocky head, a thick neck, long wings, and a forked tail. The sexes…