The black-crowned night heron N. nycticorax (Linnaeus, 1758) is a aquatic bird with twilight and night habits, with wide geographical distribution. His reproductive biology has been studied intensively at the occurrence countries, however, in Brazil, it is mentioned commonly in the ornithologists' risings, but available information don't exist on his life cycle. This work aims to contribute for the knowledge of the reproductive biology of that species in the Santa Catarina coast. The samplings were accomplished in the years from 2000 to 2002 in the Ilha dos Pássaros and of 2002 in the Ilha dos Lobos, Santa Catarina. The largest abundances of individuals and nests with eggs happened in October, and the medium length of the eggs varied between 5.02 ± 0.23 to 5.07 ± 0.21 cm and the volume 31.71 ± 2.64 to 35.92 ± 3.47 cm³ and the largest frequencies of nestlings in November, culminating the abandonment of the colony in the middle of January. They were identified seven items in the chick regurgitations of the nestlings, and the sea fish represented 44.4% of the total weight. The main predator in the colony was the black vulture, that it acted on the eggs in the beginning of the season and the nestlings in the end.
Reproductive biology; black-crowned night heron; Ardeidae
