Anhimidae

The screamers are an ancient South American family. They are related to waterfowl (family Anatidae) and gallinaceous birds (family Phasianidae). The best known species is the Southern Screamer (Chauna torquata), which is common on the plains of southern South America. Horned Screamer (Anhima cornuta) is less common and Northern Screamer (Chauna chavaria) is listed as Near Threatened.

Additional information

They have the most pneumatized skeleton of any birds: even the outermost toe bones are hollow. In addition, their skin contains many tiny air sacs. The anatomy shows clear similarity to waterfowl, yet in body structure, bill shape, and feet, the birds resemble chickens or turkeys.

The feathering is evenly distributed over the skin, rather than grouped in tracts as on most modern birds.

Screamers are often seen in pairs, with males sitting on an elevated position watching for danger as the female or family group forages. The birds forage in shallow water or while walking across water vegetation. After breeding, adjacent nesting pairs may gather in small flocks for the winter. Commonly, one or both of the pair take flight in the late morning, and soar high over their breeding area, calling loudly.

Screamers, as their name implies, have loud voices. However, rather than screams, the vocalizations are loud bulging or honking sounds, sometimes performed in a duet.

Taxonomy

 The family of screamers only consists of three species:

• Anhima cornuta (Horned Screamer)
• Chauna chavaria (Northern Screamer)
• Chauna torquata (Southern Screamer)