Many winter migratory birds from Siberian countries visit Nelapattu bird sanctuary every year. It is a breeding ground for some of the rare and endangered species like grey pelicans, open billed storks, little cormorants, sponbills, white ibies, night herons etc.
The lake is one of the largest Pelicanaries in South East Asia with more than 1500 pelicans and other birds visiting every year. The big fresh water tank of Nelapattu along with the presence of good number of Barringtonia Acutangula trees which can tolerate inundation for longer periods in the tank bed and fore shore area make this sanctuary a haven for a wide variety of bird species for breeding and roosting.
An Environmental Education Centre is situated in the sanctuary along with a museum, library and auditorium with audio visual equipment for screen slides and films on wild life. Watch towers are also available to watch the birds at the Sanctuary.