King Rail

KING RAIL

Photo Credit: Marlene Cashen & Weeks Bay Reserve Foundation
http://www.weeksbay.org/

SCIENTIFIC NAME: Rallus elegans

OTHER NAMES: Marsh hen and freshwater marsh hen.

DESCRIPTION: King rails are the largest rail found in North America. It is a medium sized marsh bird with a compressed slender compact body. Average length of an adult is 15 to 19 inches. The overall coloration of this bird is rust to cinnamon; exceptions include a white throat patch, black and white barring on the flanks and whitish belly coloration. The sexes are similar in coloration but the male is slightly larger. Wing span ranges from 21 to 25 inches. The average weight for a mature male is 12 ounces while the female averages between 11 and 13 ounces. King rails have a long slightly down curved bill. Long toes and strong legs allow for movement through their marshy habitat. Vocalizations include evenly spaced “kik-kik-kiks”, “clacks”, deep grunting notes, click and a trill.

DISTRIBUTION: The king rail has a broad geographic range encompassing most of the eastern United States. Breeding can occur in the eastern United States, portions of the Great Plains and into parts of southern Canada. Wintering birds are normally found along the Atlantic and Gulf States into Mexico and Cuba.  

HABITAT: Found in a variety of marshes including coastal, brackish and freshwater. Will inhabit marsh-shrub swamps and can be found in road side ditches, tidal rivers and rice fields.  Requires large marshes with open shallow water that merges with shrubby areas. Prefers abundant vegetation especially bulrushes, cattails and sedges. Wintering birds utilize coastal brackish and freshwater marshes but rarely salt marshes.

FEEDING HABITS: King rails are omnivorous, diurnal (daytime) feeders that prefer crustaceans and insects. In freshwater areas they utilize crayfish and in brackish or tidal marshes fiddler crabs are an important part of their diet. Aquatic invertebrates, fish, frogs, grasshoppers, crickets, and moist soil plant seeds are also consumed. Similar to owls, pellets containing exoskeletons, which are indigestible, are regurgitated.

LIFE HISTORY AND ECOLOGY: King rails are known to return to the same nesting area year after year. Nesting can begin as early as February and continue as late as August. Nesting sites are normally chosen and defended by the male. Yearly monogamous pair bonds are established on the breeding grounds. Nests are grass lined depressions on a tussock (bunch of grass); clump of vegetation or in a short shrub. Nests are concealed by grasses or vegetation bent over the nest. Abundant vegetation and stable water levels are important requirements during breeding season. Clutch size ranges from 8 to 11 eggs. Eggs are pale buff with brown spots. Incubation starts as soon as the last egg is laid and lasts approximately 22 days. Both sexes participate in nest building, incubation and care of the precocial (down covered, active) young. First flight of young occurs around the 63^rd day. Nests are preyed upon by raccoon (Procyon lotor), mink (Mustela vison), and red fox (Vulpes vulpes). Northern harrier (Circus cyaneus) and the great horned owl (Bubo virginianus) will prey on adults.  King rails migrate at night and apparently alone.  

REFERENCES:

Connecticut Department of Environmental Protection http://dep.state.ct.us/burnatr/wildlife/factshts/krail.htm (11-06-06)

Rabe, M. L. 2001. Special animal abstract for Rallus elegans (King rail). Michigan Natural Features Inventory. Lansing MI. 4pp.

http://web4.msue.msu.edu/mnfi/abstracts/zoology/Rallus_elegans.pdf (11-6-06)

Reid, Frederic A. and Brooke Meanley and Leigh H. Fredrickson. 1994. King Rail. Pages 181-191 in T. C. Tacha and C. E. Braun, eds. Migratory Shore and Upland Game Bird Management in North America. International Association of Fish and Wildlife Agencies, Washington D. C.

Species at Risk http://www.speciesatrisk.gc.ca/search/speciesDetails_e.cfm?SpeciesID=24  (3-9-06)

Author: Richard Tharp, Certified Wildlife Biologist, Division of Wildlife & Freshwater Fisheries