English: The Black-headed Ibis is one of several large waterbird species in south and south-east Asia, with adults measuring 65–76 cm in length. The white plumage is starkly contrasted against a conspicuous naked black neck and head, and black down-curved beak. Tails of adults bear light grey ornamental feathers that turn jet black during the breeding season. During the breeding season, bare patches under the wing turn blood-red. The head of some breeding adults gain a blueish tinge, or very rarely have a pink or bright red patch behind the neck. Some breeding adults also develop tufts of white feathers behind the neck, and rarely also get a yellowish colouration on the breast and back. Sexes are identical but juveniles are identifiable from adults in having greyish feathering on the neck and speckled brown-grey feathering on the wings and back. Like storks and spoonbills, it lacks a true voice-producing mechanism and is silent except for ventriloquistic grunts uttered by pairs at the nest.