The White-necked stork has glossy black plumage and green, blue and purple iridescence and is an elegant bird. Its wings and tail are also black. Its woolly belly, neck, and under tail coverts are white color, as are the lower back and rump. Its forked black tail is hidden by its long white under tail coverts and looks white if seen from below. Males and females are similar. The young are duller and browner, lacking the iridescences. Its black forehead reaches further back on the crown. The beak is pale grayish and the eyes are dark. Its feet and legs are duller.
It is a widespread tropical species that breeds in Asia, from India to Indonesia, and in tropical Africa. It is able to occupy almost any wetland environment, usually preferring flood plains, pans, rivers, ponds, dams, lagoons, mangrove swamps, swamp forests, tidal mudflats, and estuaries as well as man-made habitats, such as golf courses, roads in plantations and firebreaks.
The White-necked stork is nocturnal and can forage in the dark due to its keen night vision. This is the time when its prey comes out into the open. It is a solitary bird and is usually observed alone, walking slowly on the ground or along the water. It uses its long bill to picks up its prey. Termite emergencies are a food source as well. Although not very gregarious, sometimes they are seen in small groups or pairs near water, though they rarely wade. The stork is mainly resident and is an intra-African migrant, undergoing regional north-south movements, sometimes as a large flock. It lives in Asia as well, subject to some movements there.
The stork is mainly carnivorous, eating fish, frogs, toads, lizards, snakes, large insects and larvae, mollusks, marine invertebrates, and crabs. It feeds by walking slowly through vegetation or water stabbing at prey.
White-necked storks are monogamous, breeding with one partner for life. Essentially a solitary nester, birds may breed in loosely associated colonies of 4 to 5 pairs. Nests are built by both males and females, being a platform of sticks featuring a central bowl with a lining of fine twigs, green leaves, and grass. The nest is typically located in the fork of a large tree, at a height of 10 to 50 meters above ground or the water. Eggs are laid from August to December. The female lays 2 to 4 eggs, which are then incubated by both parents for about 30 to 31 days. Chicks are brooded and fed by both male and female and leave their nest after about 55 to 65 days to roost in a tree nearby, achieving full independence about 3 weeks later.
White-necked storks are not under threat globally, but they are near-threatened in South Africa, where there are low population numbers caused largely by habitat destruction, shooting and persecution.
According to the IUCN Red List, the total White-necked stork population size is around 35,000 individuals. Currently, this species is classified as Vulnerable (VU) on the IUCN Red List and its numbers today are decreasing.
White-necked storks mostly prey on aquatic life and thus influence their prey’s populations in those ecosystems.