The characteristic spiny appendage on the top of the Horned Screamer's head could rightfully earn it the title of "unicorn of the avian world." This bizarre relative of ducks and swans is found along rivers and freshwater marshes in northern and central South America. It tends to aggregate in pairs and small groups that never are as large as are flocks of the two other species of screamer. The Horned Screamer is herbivorous and forages by grazing and digging along the water. These birds are very vocal and can be heard dueting to make its call: ha-moo-co. This call gives it its local name jamuco or camungo. Yet, the Horned Screamer's strange physical features don't stop at its horn. It also has spurs on its wings that are used for fighting, and huge legs that contain many air sacs and are also used to make sound. All in all, the Horned Screamer is likely to make anyone feel as if they've stepped into a more prehistoric Amazon.