Giant Ibis

Scientific Name
Pseudibis gigantea
Genus
Conservation Status
Critically Endangered (CR)
Sub-Family
Threskiornithinae

Recent Nearby Sightings

View all 6 sounds

Range Map

Giant Ibis Images

Wikipedia Article

The Giant Ibis (Thaumatibis gigantea) the only species in the monotypic genus Thaumatibis, is a wading bird of the ibis family, Threskiornithidae. It is confined to northern Cambodia, with a few birds surviving in extreme southern Laos and a recent record from Yok Don National Park, Vietnam.
The Giant Ibis is a lowland bird that occurs in marshes, swamps, lakes, wide rivers, flooded plains and semi-open forests as well as pools, ponds and seasonal water-meadows in denser deciduous forest. One bird was collected in a Malay paddyfield. Formerly the Giant Ibis was believed to breed in southeastern Thailand, central and northern Cambodia, southern Laos and southern Vietnam. It was still fairly common in the Mekong River delta until the 1920s but is now almost depleted, with a small remnant population breeding in Cambodia, southern Laos and possibly in Vietnam.
Very little is known of the Giant Ibis's life history. It eats aquatic invertebrates, eels, crustaceans and small amphibians and reptiles. Insects such as locusts and cicadas are eaten regularly when abundant and seeds occasionally supplement the diet. Outside of the breeding season, frogs and mole-crickets appear to be perhaps the most significant prey types for Giant Ibises. They mainly forage in muddy substrate in shallow waters, though can feed at all depths in seasonal forest pools. Feeding flocks may consist of a breeding pair or small family group and have been observed mixing with Black Ibises. Next to nothing is known of its breeding behaviour, but it nests in trees, with a possible preference for Dipterocarpus trees. Usually, nests are located at least from human habitations, although the species is not especially shy around or fearful of humans unless persistently harassed or hunted. Females lay two eggs at the start of the rainy season, around June to September. Earthworm taken from their mounds in wet grasslands appears to be an important food source for nesting ibises of this species. In general, the species is residential but can wander widely for food or in response to disturbances. The Giant Ibis is general territory and may remain with a family group throughout the year. However, in the dry season, when they are not nesting, groups of up to 7 individuals, sometimes likely unrelated, have been observed feeding together.
This is, by far, the largest of the world's ibises. Adults are reportedly 102106 cm (4042 in) long, with an upright standing height of up to and are estimated to weigh about 4.2 kg (9.3 lbs). Among standard measurements, the wing chord is , the tail is , the tarsus is and the culmen is . The adults have overall dark grayish-brown plumage with a naked, greyish head and upper neck. There are dark bands across the back of the head and shoulder area and the pale silvery-grey wing tips also have black crossbars. The beak is yellowish-brown, the legs are orange, and the eyes are dark red. Juveniles have short black feathers on the back of the head down to the neck, shorter bills and brown eyes. It has a loud, ringing call, frequently repeated around dawn or dusk, a-leurk a-leurk.
The Giant Ibis is considered to be critically endangered. The primary causes seem to be drainage of wetlands for cultivation and the epidemic clear-cutting of forest for rubber, cassava, wood pulp and teak plantations in southeast Asia. Habitats may also face ravaging due to local human warfare. Increasing human populations in Cambodia have in turn lead to disturbance and further lowland deforestation. The ibis may be hunted for meat by people and eggs may be predated by the Asian palm civet and the yellow-throated marten, with the species certainly unable to withstand sustained predation. A reduction in seasonal pools in forest, made by now depleted megafauna such as Wild Asian water buffaloes and, may also negatively effect them. Local droughts, possibly related to global climate change, have appeared to have further decreased the breeding population. Some conservation efforts have been untaken, including the instillation on some trees with ibis nests of metal belts that prevent predators from accessing them, but the protection of ideal habitat and the increasing human populations in Cambodia continues to be a vexing challenge. Increasing ecotourism in the region and education to local people is clearly required for the species to successfully recover from the brink of extinction. The current population is estimated at 100 pairs, with a total population (including young and juveniles) of fewer than 500 individuals. However, even these figures may be optimistic.