Dark, burly medium-sized ibis. Restricted pale patches on the nape and shoulder distinguish this from all-dark ibises. Habitat preferences differ somewhat in two parts of disjunct range; Bornean birds favor mature riparian forests, while Indochinese birds are generally found in wet or flooded openings in dry forest and wooded plains. Forages singly, in pairs, or in small groups. Often disperses with the arrival of seasonal rains. Gives loud, resonating honks and croaking roars. Declining across range; status of Bornean population especially tenuous.