A vagrant Black-headed Gull (Chroicocephalus ridibundus) documented from Saint Peter and Saint Paul Archipelago: Brazil’s first record

We report the sighting of a specimen of Black-headed Gull (Chroicocephalus ridibundus) in Saint Peter and Saint Paul Archipelago (SPSPA), Brazil, in the mid-Atlantic Ocean. Chroicocephalus ridibundus is a Palearctic species that breeds throughout Europe. Part of the population spends winters in the Mediterranean and coasts of Africa, and a small breeding population remains in the northeast coast of North America. The specimen was on the island for 27 days, between 09 February and 06 March 2020. The gull was identified as a first-winter bird based on its plumage. We conclude that the vagrancy of yet another Old World species at the oceanic SPSPA in the western equatorial Atlantic Ocean was caused by the southwesterly trade winds of the Intertropical Convergence Zone. To our knowledge, this is the first documented record of C. ridibundus in the Brazilian territory.