Green Ibis

Identification

The green ibis is a medium-sized wading bird measuring 45–60 cm in length, weighing 700 to 890 g. It is unmistakably dark in good light, with breeding adults displaying glossy greenish-black plumage, pale green legs and bill, and grey bare facial skin patches. The sexes are identical in plumage, though the largest individuals tend to be male. Juveniles are considerably duller but can be distinguished from the similar glossy ibis by their bulkier shape, shorter legs, and broader wings. Like all ibises, the green ibis flies with its neck outstretched in a characteristically heavy manner, with jerky wingbeats and fewer glides than related species. It produces a distinctive hollow, hooting call that accelerates in pitch, transcribed as "kro kro" or "koro koro," described as mellow and most often heard at dawn and dusk.

Range & Habitat

This species is a resident breeder found from Costa Rica south through Central America and across South America to northern Argentina and Paraguay, with sightings recorded as far north as Honduras. The green ibis inhabits a variety of forested wetland environments, particularly swamps and the edges of rivers and lakes, at altitudes up to 500 metres. It undertakes some local seasonal movements during the dry season, making it a partially migratory species across its vast range.

Behaviour & Diet

The green ibis is largely crepuscular, being most active at dawn and dusk. Unlike most of its relatives, it is notably less gregarious and is usually observed alone or in pairs. When foraging in mixed-species flocks, it characteristically remains on the fringes, typically associating with other green ibises rather than mingling freely. The species regularly perches in trees, an adaptation to its forested wetland habitat. Its diet consists of fish, frogs, other aquatic creatures, and insects, typical of ibis feeding behaviour.

Green ibises nest in flimsy platforms of twigs constructed high in trees. Notably, they have been recorded harassing sunbitterns that nest in the same tree, suggesting competitive interactions in shared breeding habitat.

Best Time & Places to See It

The green ibis can be found throughout Central America from Costa Rica through Panama, and across much of South America. Dawn and dusk are the best times to observe this crepuscular species, when its mellow, hooting calls are most frequently heard. Look for them in forested wetland habitats—swamps, river edges, and lake margins—where they may be perched in trees or foraging in shallow water. Their preference for solitude or pair groupings means patient, quiet observation in suitable habitat offers the best viewing opportunities.

Photography Tips

The green ibis's glossy greenish-black plumage and pale green facial features are most striking in good light, so seek well-lit shooting conditions to capture its distinctive colouration accurately. The pale green bill and legs provide useful focal points for composition. Photographing this species requires patience, as it is less gregarious and more solitary than other ibises. Early morning and late afternoon light will enhance the subtle sheen of its dark plumage. When capturing flight shots, be prepared for the jerky, heavy wingbeats characteristic of the species. Tree-perching behaviour offers excellent opportunities for portraiture, particularly if you can position yourself to include the bare facial skin patches and the bird's characteristic posture.