Giant Ibis - Life History

Life History

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 4 km (2.5 mi) 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.