These are found in Australia, Indonesia, New Zealand, and Papua New Guinea in wetlands and sheltered coastal waters, mainly in the tropics and subtropics. They prefer smooth, open waters for feeding, with tree trunks, branches, stumps or posts fringing the water for resting and drying their wings. Here you can find them in our wetland areas and sheltered saltwater places like Rosslyn Bay, often seen swimming with only the snake-like neck visible above the water or drying their wings while perched on a tree or stump.
Fish form the bulk of their diet but other aquatic animals such as tortoises are also eaten, the fish are pierced from underneath, flicked onto the water's surface and then swallowed head first, smaller items are eaten underwater but large items are carried to a convenient perch and then swallowed.
Breeding is erratic, happening whenever water levels and food supplies are suitable but most often occurs in spring and summer. The nest-site is normally in the fork of a tree standing in water about 3.5 m above the surface, both sexes complete the nest, incubate the eggs and raise the young.