Green Ibis

The green ibis, or Mesembrinibis cayennensis, known colloquially as the Cayenne ibis, is a solitary wader of the ibis family Threskiornithidae. It is the sole representative of its genus, Mesembrinibis. This medium-sized bird is characterized by its short legs and long, slender, downward-curving bill. The adult's plumage is a glossy greenish-black, with pale green legs and bill, and grey patches of bare skin on the face. Juveniles present a much duller appearance but are distinguishable from their relatives by their bulkier shape, shorter legs, and broader wings.

Identification Tips

In favorable lighting, the green ibis's dark plumage is unmistakable. However, in dimmer conditions, it may be mistaken for the glossy ibis, which is bronzy-maroon and has a slimmer build and longer legs. The green ibis can be identified in flight by its heavy wingbeats and less graceful gliding compared to other ibises.

Habitat

The green ibis inhabits a range of forested wetlands, including swamps and the margins of rivers and lakes, up to an elevation of 500 meters.

Distribution

This species is native to the Americas, with a distribution extending from Honduras through Nicaragua, Costa Rica, western Panama, and South America down to northern Argentina and Paraguay. It has been known to undertake local seasonal migrations during the dry season.

Behaviour

The green ibis is primarily crepuscular, often seen alone or in pairs, and less frequently in flocks. It tends to stay on the periphery when foraging with other species. It is also known to perch in trees regularly.

Song & Calls

The green ibis vocalizes with a hollow, hooting call that accelerates, often heard at dawn and dusk. The sound can be transcribed as "kro kro" or "koro koro" and is described as "mellow."

Breeding

Nesting high in trees, the green ibis constructs a flimsy platform of twigs. There have been observations of green ibises disturbing sunbitterns nesting in the same tree.

Similar Species

The green ibis is most likely to be confused with the glossy ibis in poor light conditions. However, the green ibis is bulkier with shorter legs and broader wings.

Diet and Feeding

The diet of the green ibis includes fish, frogs, other aquatic organisms, and insects.

Conservation status

The green ibis is classified as Least Concern by the IUCN, with a large population and extensive range. Nonetheless, there is evidence of a decline in numbers. It is occasionally hunted in Central and South America. The crested caracara is a known predator, and the green ibis is also the type host for a species of bird louse, Plegadiphalus cayennensis.