Nuevo registro de nidificación de la Gaviota Cangrejera (Larus atlanticus) en la Reserva Natural Bahía Blanca, Bahía Falsa y Bahía Verde, Buenos Aires, Argentina

a new colony of olrog's gull (larus atlanticus) was found on 29 december 2006 in the bahía blanca estuary, buenos aires province, argentina. the colony was located on a small island near the golfada chica channel (38°55'50"s, 62°12'26.2"w), 50 m away from the shoreline. a total of 311 empty nests and 640 fledglings were counted. significance of this discovery for olrog's gull population size estimations is discussed bearing in mind its habit of changing colony location.