From November 1992 to June 1993, we conducted biweekly bird surveys at Ojo de Liebre (Scammon's Lagoon) on the west coast of Baja California Sur, México. During our surveys, we found four pairs of Laughing Gulls (Larus atricilla) breeding on Piedras Island (27°42'18" N, 114°09'36" W), one of five small and relatively low islands inside the lagoon (Figure 1).