60–85 cm. Large, dark ibis with distinctive blue bare mid hindcrown and nape down to upper hindneck, spreading round and becoming bold white below ear-coverts to upper.
Habitat: Marshes, seasonally flooded areas, abandoned paddy fields (including fallow sites) and other cultivation, shrub, grasslands and edges of lakes and large rivers; recent sightings in Borneo associated with riverine forests; in Cambodia inhabits dry dipterocarp forests,
Food and Feeding: Very little known until recently. Old records indicate main food includes grasshoppers, cicadas and grain, with recent unsubstantiated claims of feeding on fruit and direct observations of amphibians, small invertebrates (large worms, mole-crickets, leeches, insect and beetle larvae), eels, snakes and crabs; at trapaengs in Cambodia, preferentially feeds on amphibians,
Breeding: The white-shouldered ibis is a solitary breeder; and in its stronghold of Cambodia, it nests December–April during the mid- to late dry season November – May in dipterocarp tree canopies.
Population: BirdLife International estimate the world population at just 650 mature individuals (based on a global population estimate of 731–856 birds in 2010) within an overall range of 88,900 km2.