Rare Species Guide

  Basis for Listing

King rails are widespread throughout the eastern United States, breeding from the Atlantic Coast westward to the Great Plains and from the Gulf Coast north to Ontario, the Great Lakes states, and the eastern parts of the Dakotas. Although their historic range is not known to have changed, severe declines have been reported in the northern part of the species' range. Populations in the southern United States, particularly in Florida and Louisiana, appear stable.

In Minnesota, the king rail has occurred at widely scattered localities in the southern half of the state. One notable exception is a summer record from Duluth in 1984 (not depicted on range map). Roberts (1932) referred to an observer finding nine nests in 1898 in Faribault County and a pair nesting in nearly every prairie slough. Roberts himself considered the king rail a regular species in Hennepin County and common at Heron Lake in Jackson County. From 1940 to 1970, the king rail declined significantly across its range in southern Minnesota, with nesting records reported from only 15 counties (Green and Janssen 1975).

Between 1970 and 1980, only three breeding season records of king rails were recorded. As a result of this decline, the king rail was designated a state special concern species in 1984. Only two breeding season records were recorded between 1980 and 2000, including a 1992 record from Hennepin County. The loss and degradation of wetland habitats has probably contributed to the species' decline, although previously occupied sites that still appear suitable are not being used. As a result of the continuing decline, the king rail was reclassified as an endangered species in Minnesota in 1996.

  Description

The king rail, with its strongly barred flanks and long, slightly curved bill, is similar in appearance to the much more common Virginia rail (Rallus limicola). King rails however, are much larger in size, have rusty-brownish cheeks, and a darker bill. The king rail is a secretive marsh bird usually detected by its raucous and variable calls. King rail calls are generally much deeper than the similar sounding calls of the Virginia rail.

  Habitat

Throughout their range, king rails are found in a wide variety of shallow freshwater, brackish, or saltwater marshes. A complex of wetland types is ideal for breeding, as densely vegetated sites are used for nesting, and drier areas are used for foraging by pairs and their broods (Reid 1989). It has been suggested that king rail distribution may be dependent on the muskrat (Ondatra zibethicus), whose activities in marshes create openings used as feeding areas by rails (Meanley 1992).

  Biology / Life History

King rails overwinter in tidewater areas along the Atlantic and Gulf coasts. They migrate individually, returning to the summer breeding grounds in late April. Males establish small territories that they defend from other rails. Often one or more symbolic nests are built in a territory before the true nest is made. Nests are usually placed in a clump of grass on a platform the birds have constructed. Vegetation surrounding the nest may be pulled over the nest to form a canopy. Males take the most active role in nest building, and both sexes incubate the eggs. King rails have large broods, averaging 10-11 eggs. Chicks are precocial, and leave the nest about an hour after hatching. During their first 3 weeks, chicks are fed by their parents, but soon begin to find food on their own. They generally become independent of the adults by late summer. Most king rails depart for overwintering grounds in fall, although in the southern portion of their range, some individuals may remain on the breeding grounds year-round. The species feeds mainly on crustaceans and aquatic insects, but it will also eat mollusks and fish if they are abundant and easy to catch. Small animals are swallowed whole, but large prey items are broken into pieces before being eaten or fed to the young (Meanley 1992).

  Conservation / Management

Programs aimed at halting the destruction and degradation of marshes will benefit the king rail as well as many other species. However, wetland management regimes that benefit king rails differ from those typically planned for waterfowl, as wetlands of greatest value to rails are shallower and have a greater percentage of emergent vegetation cover than those managed for waterfowl.

  Conservation Efforts in Minnesota

With only three summer observations reported between 1980-2008, the king rail appears to be all but extirpated as a nesting species in Minnesota. Efforts should be made to determine more precisely the current status of this species in Minnesota. It is remotely possible that king rails still occur in the state, particularly in the extensive, remote marshes along the Mississippi River in southeastern Minnesota.

  References and Additional Information

Green, J. C., and R. B. Janssen. 1975. Minnesota birds: where, when, and how many. University of Minnesota Press, Minneapolis, Minnesota. 217 pp.

Meanley, B. 1992. King Rail (Rallus elegans). Number 3 in A. Poole, P. Stettenheim, and F. Gills, editors. The birds of North America. The Birds of North America, Inc., Philadelphia, Pennsylvania.

Reid, F. A. 1989. Differential habitat use by waterbirds in a managed wetland complex. Ph.D. Dissertation, University of Missouri, Columbia, Missouri. 240 pp.

Roberts, T. S. 1932. Birds of Minnesota. Volume 2. University of Minnesota Press, Minneapolis, Minnesota; London, H. Milford, Oxford Universtiy Press.