The Glossy Ibis is a medium-sized, dark wading bird with a long, decurved bill, an appearance responsible for the common name "black curlew." In good light, the plumage is metallic bronze with a striking green tinge.
This cosmopolitan species is the most widespread ibis species, with populations in Central and South America, the Greater Antilles, southern Europe, Africa, Asia, India, and Australia. In North America, it is restricted to eastern regions from New Brunswick through Florida and Louisiana and sporadically inland. In western North America, it is replaced by the widespread and closely related White-faced Ibis (Plegadis chihi). The Glossy Ibis resembles the White-faced Ibis, but during breeding season, the latter has distinctive white feathers along the facial skin.
The Glossy Ibis uses a wide variety of inland wetland habitats, and to a lesser extent coastal lagoons and estuaries. Individuals that nest in coastal habitats often forage inland in fresh water. They are gregarious year-round and nest colonially, usually with a variety of heron species. The species often disperses widely after breeding, and is seminomadic in parts of its range. This tendency to wander may be responsible for the monotypic status of the species-no subspecies are currently accepted.
The Glossy Ibis is a tactile forager, probing substrate with its long, decurved bill. It feeds mainly on insects and crustaceans, but plants, such as cultivated rice, may constitute a major portion of its diet at some seasons. In contrast to the White-faced Ibis, which suffered population declines during the DDT era, the Glossy Ibis during the twentieth century has gone from a rare and local Florida species to a locally common breeder as far north as Maine and an occasional breeder into the Maritime Provinces of Canada-a remarkable range expansion.
The Glossy Ibis is a generally understudied species in North America (but see Baynard 1913a, Bent 1926, Palmer 1962a), so, for this monograph, we have drawn on information about the species worldwide (see Cramp and Simmons 1977, del Hoyo et al. 1992, Marchant and Higgins 1990).