Green billed toucan in the rain, Atlantic Rainforest, Brazil

The Green billed Toucan is the smallest species of Ramphastos. This also is the most southern species of toucan, occuring from east central Brazil south to eastern Paraguay and northeastern Argentina. In parts of its range, in southeastern Brazil, the Red-breasted Toucan overlaps geographically with a distinctive subspecies (ariel) of Channel-billed Toucan (Ramphastos vitellinus). Both of these toucans are superficially similar, with an orange throat and breast, red belly and tail coverts, and red orbital skin. But they easily can be distinguished by bill color: mostly black in Channel-billed, and mostly light green in Red-breasted. These two species also have similar “croaking” vocalizations, although the calls of Red-breasted are more raucous. The two species tend to segregate by elevation, with Red-breasted in montane forests and Channel-billed restricted to the lowlands.

It is one of the smallest species of Ramphastos toucans, weighing 265–400 grams (9.4–14.2 oz.) and measuring 40–46 cm (16–18 in) long in total.[2] Its beak is one of the shortest of Ramphastos toucans at only about 10 cm (4 in) in length. Its breast is actually orange, with yellow at the sides. The beak is mostly pale greenish-horn, leading to its common name. In aviculture, their requirement of spacious cages, a high fruit diet and sensitivity to hemochromatosis (iron storage disease) make them difficult to maintain for novice keepers. Not globally threatened (LEAST CONCERN). Probably reasonably common in general.