Along ten years of study of a common dolphin from the brazilian coast, Sotalia brasiliensis Van Beneden, 1874, I could see some occasions of feeding associations of this dolphin with five species of birds, Sula leucogaster (Boddaert, 1783), Fregata magnificens Mathews, 1914, Sterna hirundinacea Lesson, 1831, Larus dominicanus Lichtenstein, 1823 and Phalacrocorax olivaceus Humboldt, 1895. The commonest association observed was between the dolphin and S. leucogaster, and in all the associations was characterized the commensalism, with advantaged to the birds.
Sotalia; Cetacea; sea birds; feeding; behaviour