Breeding birds (male and female) have dark red-brown necks, breasts and undersides; there is a white rim to the face, dusky-streaking on the head fades. Male and female are similar; males have longer beaks.
Immature birds are duller in colour than adults with dusky breast and belly and less curved bill. Head and neck are patchy white.
In flight, Glossy Ibis resemble Black Cormorants with regular flapping alternating with short glides, but Glossy Ibis hold their necks lower, inclined towards the ground
Gregarious birds living in flocks of up to thirty or more birds in shallow freshwater swamps and mud flats, particularly where trees and shrubs provide shelter. Also in paddocks near water. When feeding they walk along using the bill to probe for frogs, snails, spiders and insects. Can pick insects off plants. Wander nomadically in search of feeding grounds.
Found throughout Australia except for WA desert, but only occasionally seen in eastern Victoria, Cape York or central Australia. They do not use regular breeding sites but appear to regularly breed in the Murray-Darling basin dispersing in mid-year to the wetlands of northern Australia.
Breeds September to April. Nest is a platform of sticks, generally lined with aquatic plants; built between bushes or trees growing in water in secluded areas. Breeds together in small colonies of ten to twenty pairs. Nests are built lower than other ibises just above water level or on the edges of the water. Egg-laying continues for about five weeks, after other ibises have completed their clutches.
Glossy Ibis lay up to six eggs, most often three. Eggs are green-blue, elongate-oval 52mm x 35mm. Both sexes incubate the eggs; brooding begins as soon as the first egg is laid so eggs hatch in sequence and the oldest, first-hatched, chick may out-compete the others for food so later hatchlings die.
About two weeks after hatching the young begin roaming over the nesting bushes. They can fly at about one month and can feed themselves; fledglings stay in or around the nest for four to five weeks, both parents feed them. Later, they feed with their parents during the day and roost with them late at night, settling in trees with other ibis species, spoonbills and herons.