Courtesy Kenn Kaufman
The King Rail's breeding range has shrunk dramatically in the last 60 years. Once found regularly from the upper midwest southward through eastern Texas, then eastward through the coastal plain, and up into New England, today, the King Rail is largely restricted to the coastal plain from Texas through the lower Mississippi River Valley and all of Florida. This bird also occurs close to the Atlantic coastline north to New Jersey.
King Rails are best supported by extensive wetlands with shallow water and a mosaic of plant species, such as grasses, cattails, sedges, and millet. These marsh birds prefer fresh water, but will also use brackish and tidal wetlands. King Rails tend to breed in the center of marshes, but their chicks depend on drier areas for foraging.
Most often, King Rails forage by walking through shallow water or over moist, thickly vegetated ground. Like other large rails, King Rails are omnivorous. In the summer, their diet depends heavily on aquatic animals and insects, including crayfish, crabs, small fish, frogs, grasshoppers, and beetles. During fall and winter, they consume more aquatic plant seeds, especially millet and rice. King Rails have also been known to eat small mammals and acorns.
In the southern United States, King Rails form apparently monogamous pairs as early in the spring as February. The male courts the female by strutting around her with his tail cocked to reveals its white underside. He occasionally pauses to call "kik, kik, kik!" Once formed, the pair defends territories from other rails. Constructed by both sexes, the grassy nest is hidden in dense grasses and sedges, and elevated above damp ground or shallow water The pair incubates 10 to 12 light yellowish eggs, marked with small brown spots; they defend eggs and chicks by rushing at intruders or pretending to be injured. After about three weeks, the black, downy chicks emerge, ready to walk but dependent on the adults for food for the next nine weeks. Both adults brood the chicks, which also huddle together for warmth. Young King Rails begin to fly in about nine weeks, and families appear to break up before migration. In the south, some pairs may produce another brood before fall.
Although some southern populations do not appear to migrate, northern King Rail populations migrate south in September. Spring migrants have been observed in early April. Two banded individuals were recaptured 350 and 1000 miles, respectively, from one banding station. King Rails killed by radio towers suggest a nocturnal, individual migration.