Birds of the Alcatrazes archipelago and surrounding waters, São Paulo, southeastern Brazil

Alcatrazes island and surrounding islets, 35 km from the mainland in southeastern Brazil, are a young archipelago created by rising sea levels around 7,000 years BP. The main island covers 135 ha and is the only to harbour forest, the four islets showing exposed rock, grasses and sedges. A total of 82 species, of which six breeding seabirds, has been recorded in the archipelago. Another 11 seabirds were documented in the waters surrounding the islands. Alcatrazes holds the largest Magnificent Frigatebird, Fregata magnificens, colony in the southern Atlantic, as well as the threatened Brazilian population of Royal Terns, Thalasseus maximus. The landbird community is impoverished, with few resident species but a large number of seasonal visitors, including Atlantic forest species and intertropical and southern migrants.