Gray-headed Swamphen Life History

Habitat

Gray-headed Swamphens inhabit wetlands that have at least some patches of vegetation that emerges above the water level. Like many other swamphen species around the world, they adapt well to human-modified environments. In Florida, they are fairly common in freshwater sloughs and sawgrass marshes of the Everglades. They also frequent ponds in golf courses and other developments, ditches, borrow pits, stormwater treatment areas, water conservation areas, and many other artificial wetlands, and it is common to see them feeding in the open on lawns and fairways, well away from water’s edge. They also forage in agricultural lands, especially sugarcane and rice fields. Gray-headed Swamphens avoid saltwater environments for the most part. Among the more common plant species found where swamphens breed in Florida are sawgrass, southern cattail, common cattail, coastal plain willow, pickerelweed, spikerush (an important food), and various species of water lily, arrowhead, and panicgrass. Back to top

Food

Gray-headed Swamphens eat mostly plant matter, especially the shoots and tubers of semi-aquatic and aquatic plants such as reeds and rushes. In Florida, they consume spikerush (club-rush), sawgrass, cattail, rice, and various other grasses. They forage by walking slowly through shallow wetlands and either picking at vegetation with the bill or grasping it with the bill and pulling it up. They use the huge feet both to balance themselves and to grasp plant food and bring it to the bill to eat. Like Purple Gallinules, with similarly long toes, they are agile climbers and sometimes forage from a perch in a tree, bush, or reed bed, normally not more than a few yards higher than the water’s surface. Swamphens often strip off the outer layers of reeds with the bill to reach the softer core. They occasionally consume snails and other mollusks, insects, fish, amphibians, reptiles, birds (including nestlings and eggs), and in some places readily accept handouts of seed, fruits, or vegetables in backyards. Back to top

Nesting

Nest Placement

In Asia, the species nests on floating vegetation a few feet from the water’s edge or in reed beds. Groups may build several nests and use a well-hidden one for eggs.

Nest Description

Females (with help from males) construct loosely woven, circular nests of aquatic and semi-aquatic vegetation, always of plant species found in the vicinity. Nests measure on average (in Asia) about 13 inches across, 9.7 inches tall (above water level), with an interior cup 8.2 inches across and 1.8 inches deep.

Nesting Facts

Behavior

Gray-headed Swamphens have not been the subject of much study, but in general swamphen species spend much of the day foraging, preening, and resting. They walk along the edges of wetlands, in shallow wetlands, or on land, looking for food (both plant and animal), occasionally swimming to reach some food source. Their long toes permit them to walk across floating vegetation such as lily pads. When disturbed, they run rapidly, sometimes flapping wings much like a chicken. They fly well, although their flight appears labored and ungainly at first. Mating systems in swamphens vary around the world. Some are socially monogamous, but most have a system of communal (group) breeding that involves several breeding females and males that collectively defend a territory. The females of the group usually share a nest, and they may have nonbreeding nest-helpers that assist with nest construction, chick rearing, and perhaps incubation. Because the weather is mild in southern Florida, Gray-headed Swamphen groups appear to nest multiple times per year there, sometimes raising three broods in one year. The bonds in these breeding groups are maintained by behaviors such as courtship feeding and mutual preening, and these may be performed between any members of the group, regardless of sex. When members of one group come into contact with members of another (usually at territory boundaries), they often signal their displeasure by raising up, hunching down, flicking the tail, raising the wings, or displaying the bill and frontal shield. If threat displays are not sufficient, the birds may fight by flying at each other feet-first and attempting to peck. Back to top

Conservation

Gray-headed Swamphens in North America have expanded rapidly since their introduction in the mid-1990s. They are a source of conservation concern chiefly for the possible negative impacts this exotic species may have on native bird species, plant communities, and crops. It also appears to be aggressive toward smaller rail species such as Common Gallinule, especially when nesting.

Credits

Kushlan, J. A., M. J. Steinkamp, K. C. Parsons, J. Capp, M. A. Cruz, M. Coulter, I. Davidson, L. Dickson, N. Edelson, R. Elliott, R. M. Erwin, S. Hatch, S. Kress, R. Milko, S. Miller, K. Mills, R. Paul, R. Phillips, J. E. Saliva, W. Sydeman, J. Trapp, J. Wheeler and K. Wohl (2002). Waterbird conservation for the Americas: The North American waterbird conservation plan, version 1. Washington, DC, USA.

Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.

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