The white-shouldered ibis is a large species of bird in the family Threskiornithidae. It is native to small regions of Southeast Asia, and is considered to be one of the most threatened bird species on this part of the continent.
Region
Southeast Asia
Typical Environment
Occurs patchily in lowland deciduous dipterocarp forests, seasonal wetlands, and along large rivers with exposed sandbars. Core populations persist in northern and eastern Cambodia, with remnant groups in southern Laos and parts of Borneo (Kalimantan). It uses trapaeng (seasonal pools) during the dry season and forages on exposed mud and sand as waters recede. Nesting typically occurs in tall emergent trees near feeding areas. Human disturbance and habitat conversion strongly limit its distribution.
Altitude Range
Sea level to 400 m
Climate Zone
Tropical
Ease of Keeping
Beginner friendly: 1/5
The white-shouldered ibis is one of Southeast Asia’s most threatened waterbirds, now surviving mainly in northern and eastern Cambodia with smaller numbers in Laos and Borneo. It favors open, seasonally dry forests with scattered wetlands and sandbars, habitats that have declined sharply. Its conspicuous white shoulder patch makes it easier to identify in flight. Conservation efforts focus on protecting seasonal pools (trapaeng), riverine sandbars, and nesting trees from disturbance.
Pseudibis davisoni on a 2014 stamp of Indonesia
Aspects of the head, by Arnoul in G. Masson (1878)
Temperament
wary and cautious
Flight Pattern
strong flier with steady wingbeats and brief glides
Social Behavior
Usually seen singly, in pairs, or small loose groups, often roosting communally in tall trees. Nests singly or in small, scattered colonies on large emergent trees near seasonal wetlands or rivers. Breeding coincides with the late dry season when pools concentrate prey, and adults defend nest sites from disturbance.
Migratory Pattern
Resident
Song Description
Vocalizations include deep, resonant honks and harsh grunts, especially at roosts and nesting sites. Calls can carry over open forest at dawn and dusk and are used in pair communication and territorial displays.
Plumage
Mostly dark brown to blackish with a contrasting white patch on the upperwing coverts ('shoulder'), visible at rest and in flight. Head and upper neck largely bare and dusky-grey with sparse bristles; plumage has a slight gloss in good light. Long, downcurved bill is horn to grey. Overall silhouette is lanky with long legs and neck.
Diet
Feeds mainly on aquatic and terrestrial invertebrates such as beetles, grasshoppers, crabs, snails, and insect larvae. It also takes small fish, frogs, and other small vertebrates when available. Foraging involves probing soft substrates, picking prey off exposed mud or sand, and gleaning around shrinking pools.
Preferred Environment
Seasonal pools (trapaeng), drying river margins, sandbars, grazed clearings, and occasionally rice fields with shallow water. It favors open sites with sparse ground cover and minimal human disturbance.
