Screamers: Anhimidae

Screamers are large, goose-like birds that swim well and live in and near fresh water. They have a horn-like projection on top of their heads, and a short, downcurved bill. Their legs are long and thick, and their feet are only shallowly webbed. Wings are long and broad, which makes them able to soar well. They weigh 5 to 7 pounds (2 to 3 kilograms) and measure 28 to 36 inches (71 to 92 centimeters) long.

Each wing has a sharp, spur-like outgrowth of bone. These spurs, which are used as weapons, are covered with keratin, the same material that makes up hair and fingernails. Body coloration is black or gray on top with lighter hues below.