SUNBITTERN Eurypygidae The Sunbittern (left and below) is a wonderful water-edge bird of the Neotropics, ranging from Guatemala to the Pantanal of southern Brazil/Paraguay. In heavily forested country, such as Central America or the Amazon basin, it can be difficult to locate and approach as it hunts along clear streams and rivers. A group of us found it in Panama, for example, by wading up a small crystal-clear stream that crossed Pipeline Road until we flushed one from the bank. In the Venezuelan llanos and Brazilian Pantanal, however, sunbitterns are more easily found out in the open, hunting along the edges of drying up ponds (but still tending to stick to the shade and nearby cover). Along these edges it uses binocular vision to search methodically for frogs and insects.

The handsomely patterned Sunbittern looks a bit like a horizontal heron. It has a fairly long, straight bill; a long slender neck; a long protruding tail; and short legs used for stalking waterside prey. It is generally a cryptic bird, but hidden in the wings are two enormous bright "eyes" or "sunspots" that are used both in display, and to startle potential predators. Alas, my photos fail to show this wonderful feature, but great shots appear in Thomas (1996). The photo (right), however, does contain a cryptic reflection in a quiet, shadowy pool.

At one time there were thought to be two species of sunbitterns -- the nominate helias in the Amazon basin and major of Central America to coastal Ecuador. As to the latter, it is questionable whether the range of the Sunbittern extends north into southern Mexico. It was traditionally reported from the Atlantic slope of Chiapas, but there are no specimens known and no recent sightings (Howell & Webb 1995). Today, these taxa (plus the lower subtropical race meridionalis in central Peru) are considered subspecies of a single widespread species. There are no fossils of sunbitterns, and their taxonomic position has been the subject of some debate. Morphological and behavioral characteristics are shared with the Kagu of New Caledonia (and egg-white protein analysis implies affinities there) and painted-snipes of the Old World. But biochemical analysis does not support this latter potential relationship; painted-snipes are considered Charadriiformes (shorebirds) while sunbitterns are placed in the Gruiformes (cranes/rails order). Spectacular (and usually hidden) patterns in the wings are shared by both the Kagu and Sunbittern, and both may have originated from the Mesozoic biota of Gondwanaland (Thomas 1996).

Photos: The photos of Sunbittern Eurypyga helias were taken in the Pantanal of Mato Grosso, Brazil, in July 1999. Photos © D. Roberson; all rights reserved.

Bibliographic note:

There is no "family book" per se of which I'm aware, but an excellent introduction to the family (with some superb open-wing shots) is in Thomas (1996).

Literature cited:

Howell, S. N. G., and S. Webb. 1995. A Guide to the Birds of Mexico and Northern Central America. Oxford Univ. Press, Oxford & New York.

Thomas, B. T. 1996. Family Eurypygidae (Sunbittern) in del Hoyo, J., Elliott, A., & Sargatal, J., eds. Handbook of the Birds of the World. Vol. 3. Lynx Edicions, Barcelona.