The Northern Bald Ibis has black plumage with iridescent green and purple hues; the head of adults is bare, except for a sort of crown of longer feathers on the nape of the neck. The legs and beak are red; the sensitive, downward-curving beak is specialized for hunting insects and larvae found in the soil. This bird is not necessarily monogamous; it nests in colonies, and both partners participate in nest-building, incubating the eggs, and caring for the young once they hatch. The female lays about four eggs; it takes another 45 to 50 days after hatching for the chicks to be able to fly. At first, the young will fly and forage with their parents; afterward, they will join other birds of their own age to form small flocks. In the fall, they will migrate for the first time; the flock will join experienced birds and learn the migratory route to their wintering grounds from them.