It is common to see this species perched on fence posts, in shallow lagoons, always near or on the water. It is a permanent resident, and some populations may migrate north during the southern hemisphere winter.
Tidal waters, lakes and coastal regions, generally within protected estuaries, rivers or lagoons. May nest inland in dead trees near reservoirs and on offshore islands. In Latin America, it is found in a wide variety of areas inland and on the coast, in warm and cold waters.
It mainly feeds on large numbers of small fish in shallow sheltered waters, and its prey is typically 5 to 12 centimeters long. It also consumes tadpoles, frogs, and aquatic insects. In the wide variety of tropical habitats, it may also take other prey.
Resident bird most likely to be seen in winter and spring.
It is common in lagoons and freshwater reservoirs.