Little information is available on the avifauna of San Ignacio Lagoon. The only published accounts dealing specifically with this area are those of Huey (1927), who visited the lagoon over 60 years ago, and Bancroft (1927), who mentioned this area as breeding ground for the Osprey (Pandion haliaetus) and some species of waterbirds. As far as we know, the only other ornithological research there is that of Reither man and Storrer (1981), who studied the Osprey population of Ballena Island from 1980 to 1983.
During 1988 and 1989, Danemann (1991) spent 117 days at San Ignacio Lagoon, studying primarily the community ecology of birds breeding on Ballena Island. Here we summarize observations recorded during those visits.