On the Brazilian coast, those species nest sympatrically, from the islands of Espírito Santo State to Santa Catarina State. From 1999 to 2002 a sampling program was implanted with the objectives of studying the breeding of S. hirundinacea and S. eurygnatha along Santa Catarina coast. The size of colonies in number of couples, reproduction strategy, length, width, weight and the volume of the eggs, as well as bill length and weight of the nestlings were determined. S. hirundinacea youth weight/length relationship was estimated and the reproductive success of the terns colonies was also determined.
Conservation; seabirds; terns
