Sunbittern: Eurypygidae

Sunbitterns are often solitary, that is, they frequently live alone. However, they are sometimes found in pairs, usually male and female breeding partners. Sunbitterns are not particularly shy, but will fly to the low branches of trees if they are disturbed. Sunbitterns do not migrate, but stay generally in the same place throughout the year. However, individuals who live in dry areas may move short distances in order to find appropriate habitat.

Sunbitterns are known for their defensive posture, which they use to frighten away potential predators. The defensive posture involves opening the wings and rotating them forward to reveal the sunburst pattern, and raising and fanning the tail at the same time. This causes the sunbittern to appear to be a large and alarmingly colored bird. In order to protect a nest and chicks, adult sunbitterns will also perform a "broken-wing" display in which one wing is dragged along the ground as if broken. By drawing attention to what appears to be a helpless adult, sunbitterns are able to distract attention from the more vulnerable nest.

The sunbittern song is a high, ringing whistle and is sung most often in the morning. Sunbitterns also have an alarm call that is used to warn others of danger.

Breeding in sunbitterns occurs during the rainy season. Courtship involves calls and singing duets as well as flight displays, head bobbing displays, preening, and begging displays. Both males and females participate in nest-building. The nest is usually built on a horizontal branch 3 to 23 feet (1 to 7 meters) above the ground and consists of a large bowl of decaying leaves, mud, and other plant material. More rarely, nests are built directly on the ground. The nest is usually placed under the cover of vegetation and close to water. The female lays two or three eggs at a time. These are pink in color, often with purplish-brown spots, and hatch after twenty-seven to thirty days. Chicks hatch already covered with down, fine fluffy feathers, and with their eyes open. One chick often hatches one or two days before the other. Both males and females incubate, or sit on, the eggs, and both help feed and take care of the chicks once they hatch. Chicks are able to stand and flap their wings a week after birth, and leave the nest after approximately thirty days.

The sunbittern's defensive posture, rotating the wings forward, causes the sunbittern to appear to be a large and alarmingly colored bird. (© François Gohier/Photo Researchers, Inc. Reproduced by permission.)