Mostly nocturnal. Roosts in colonies in trees near water by day or on islands on the ground in treeless areas. Flies with slow, silent wingbeats. Birds leave colony in unison, travelling to wetland feeding grounds. Forages alone from early evening and before dawn for fish and other aquatic prey.

Found in brackish or fresh, permanent or semi-permanent water. Swamps, lagoons, estuaries with mangroves.