The Green Ibis (*Mesembrinibis cayennensis*) is a striking, medium-sized wading bird native to the wetlands and forested rivers of Central and South America, distinguished by its unique, iridescent plumage. Unlike the stark white of its more famous relatives, this ibis boasts a deep, glossy green-black body that shimmers with bronze and olive highlights in the sunlight, complemented by a pale, buffy-yellow bill and legs. Its most special feature is its solitary, crepuscular nature and a distinct, far-carrying call that sounds like a hollow, wooden "tok-tok-tok," often heard at dusk as it probes muddy shores for insects, crustaceans, and small amphibians. With a long, decurved bill perfectly adapted for foraging in soft substrates, the Green Ibis remains a secretive and enchanting gem of neotropical waterways.

Faits amusants

Unlike its more flamboyant relatives, the Green Ibis is a secretive forest dweller that often freezes mid-step with its beak pointed skyward, a bizarre camouflage trick that makes it resemble a broken branch. It has a unique, un-ibis-like call—a series of resonant, hollow *kloo-kloo* notes that sound more like a frog or a distant woodwind than a bird. Its iridescent green plumage is so effective at blending into dappled jungle light that it can vanish from sight while standing in the open, and it possesses a remarkably long, decurved bill that it uses not just for probing mud, but for deftly snatching crabs and large insects from the surface with a rapid, scissoring motion.

Habitats et répartition

The Green Ibis is found throughout much of tropical South America, east of the Andes, from Colombia and Venezuela through the Guianas, Brazil, and into eastern Peru, Bolivia, Paraguay, and northern Argentina. It also occurs in Panama and Trinidad. Its preferred habitat consists of dense, swampy forests, mangrove swamps, and the edges of rivers, lakes, and oxbow lakes, particularly those with muddy banks and shallow water. It avoids open grasslands and dry forests, instead favoring humid, lowland areas where it can forage for aquatic invertebrates and small vertebrates in soft mud and shallow water.

Comportements & Reproduction

The Green Ibis is typically observed alone, in pairs, or in small, loose groups, and it does not form large, dense breeding colonies like many other ibis species. Mating pairs are monogamous for at least a single breeding season, and courtship involves mutual preening, bill-clattering, and stick-presentation displays. The nest is a simple platform of sticks built in a tree fork, often over water or in dense swampy forest. Both parents share incubation duties for the single clutch of two to three eggs, which lasts around 22 to 24 days. A notable reproductive strategy is their strong site fidelity; the same nest tree may be reused and repaired year after year. The chicks are altricial and are fed regurgitated food by both adults, fledging after approximately five weeks. Unlike some colonial wading birds, the Green Ibis does not engage in synchronous breeding, with nesting timing varying by local rainfall patterns.

Alimentation

The Green Ibis is primarily a carnivorous wader, its diet consisting almost entirely of small aquatic and terrestrial animals. It forages by probing its long, decurved bill into soft mud, shallow water, and leaf litter to capture prey such as insects (especially beetles, dragonfly larvae, and grasshoppers), spiders, small frogs, lizards, snails, and earthworms. An interesting aspect of its feeding behavior is that it is less social than many other ibis species, often foraging alone or in small family groups rather than in large flocks. Unlike some ibises that feed in open water, the Green Ibis prefers the dense, shadowy understory of humid forests and swamps, using the dim light to surprise its prey. Additionally, its diet shows a notable seasonal shift during the breeding season, when adults increase their intake of protein-rich insects and small vertebrates to feed their growing chicks.

Couleurs

The Green Ibis is predominantly dark greenish-black with a distinct bronze or olive gloss on its back and wings, appearing almost black in low light. Its head and neck are a slightly paler, grayish-green, and it lacks the white markings or bright facial skin seen in other ibises. This uniform, iridescent coloration provides excellent camouflage in the dim, shadowy swamp forests and muddy riverbanks it inhabits, helping it blend with wet foliage and dark water.