This is a resident breeder from Honduras through Nicaragua, Costa Rica and western Panama, and South America to northern Argentina.

The green ibis was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae.

[2] Gmelin based his description on the "Cayenne ibis" that had been described in 1785 by the English ornithologist John Latham in his book A General Synopsis of Birds .

[13] Breeding adults have glossy greenish-black bodies, pale green legs and bill, and grey bare facial skin patches.

Juveniles are much duller, but can be distinguished from the similar glossy ibis by their bulkier shape, shorter legs and broader wings.

In poor light, however, it might be confused with the glossy ibis; the latter (which is bronzy-maroon in color) has longer legs and a slimmer build.

[20] Because of its huge range and large population, the green ibis is rated as a species of least concern by the International Union for Conservation of Nature; however, its numbers do appear to be decreasing.

[21] The crested caracara is known to prey on green ibis, with a pair observed chasing and attacking one in flight, driving it to the ground.