Clapper Rail

Rallus longirostris

(c) Ron Wolf
  • RALLIDAE
  • Coots, Rails
  • Gruiformes
  • Rascón Picudo
  • Râle gris
Introduction

The Clapper Rail, or Salt-water Marsh-hen, struts through North America's coastal marshes, pumping its head and bobbing its tail. With a narrow body and good swimming skills, it moves through dense marsh plants at all water levels. This relative of cranes and coots was a popular gamebird in the 19th Century. Today, 3 of its subspecies are Endangered.

(c) Glen Tepke
Appearance Description

Often compared to a chicken, the Clapper Rail is a medium-sized marsh bird with a thin body and fairly long bill. It measures about 14.5 inches long with a 19 inch wingspan and weighs about 10 ounces. Its various subspecies present remarkably different plumages. West and Gulf Coast birds closely resemble the King Rail, and require care in identification. In general, these subspecies have an orangish upper belly, chest, neck and face. The lower belly into the undertail is grey with thin white bars. The undertail flashes white along its sides. The upperparts are dark brown streaked with yellowish. The legs are stout, the thick bill is orange, and the eye is red. Gulf Coast birds are a bit duller and have grey in the face. Atlantic Coast birds are even duller, with a grey wash overall and a grey face.

Range Map
Courtesy Kenn Kaufman
Range Distribution

Along North America's Atlantic and Gulf coasts, the Clapper Rail is a permanent resident from about New Jersey southward into Tamaulipas, Mexico, including the islands of the western Caribbean. A disjunct population occupies most of the Yucatan Peninsula's coast. On the west coast the distribution is patchy, and it resides from San Francisco Bay southward through Baja California to Nayarit. A population also resides in the Lower Colorado River valley, including the Salton Sea. A small population of migratory Clapper Rails extends from northern New Jersey into southern New England.

Of the approximately 21 recognized subspecies of Clapper Rail, the 3 that are Endangered are in the West. The California Clapper Rail (R. l. obsoletes) occurs in the San Francisco Bay area. Its range has shrunk dramatically in the last 120 years. The Light-footed Clapper Rail (R. l. levipus) ranges in southern California from about San Quentin Bay to Baja California Sur. The Yuma Clapper Rail (R. l. yumanensis) lives along the Lower Colorado River and its adjacent marshes, southward to San Blas, Nayarit, along the Mexican Pacific coast.

Habitat

In summer, this rail inhabits salt marshes with open water and uses the wetter parts, where open water and plants mix. Typical plants in this situation include cordgrass, pickleweed, mangrove, and needlerush. Thick vegetation at the edge of the marsh may be important when the water is high. Emergent and barely submerged plants facilitate travel, provide some cover, and harbor prey. In Arizona, the Yuma Clapper Rail uses wetlands with emergent plants like bulrush, cattail, and sedge. Generally avoiding ice and very cold water, wintering rails may shift into more dense vegetation, higher parts of the marsh, or more mature plants.

Feeding

With an omnivorous diet, the Clapper Rail eats what it can find and swallow. Locating prey by sight and perhaps by smell, it picks items from new plant growth, the ground, and floating vegetation. It may also poke into mud or dead vegetation, but not deeply. The diet includes crabs, shrimp, insects, marine worms, the seeds of water plants, mussels, clams, and snails.

Reproduction

Males are territorial year round but are most aggressive during the breeding season and will chase off any other vocalizing male. The pairs form monogamous bonds that appear to last for the season. The male calls the female with a series of "keks," that sound like stones being tapped together. He courts her with exaggerated postures that feature the flash of his white under tail coverts. Using course marsh plants, the pair raises a platform from just a few inches to 5 feet above the water or ground. Set among thick marsh vegetation, the nest may have a cover and an access ramp. Several other mounds are constructed as roost sites for the chicks.

5-8 whitish eggs, splotched with shades of brown, are incubated by the pair for about 20 days. Covered in black down, the chicks are soon able to walk and swim, but need warmth from the adults. When threatened, they may hide or be carried to safety by an adult. In about a week, the adults split the brood and care for their own portion, until the young reach independence at about 6 weeks old. The pair may raise a second brood.

Migration

Only the Atlantic population from New England south into the mid-coast of North Carolina makes a traditional migration. Spring migrants probably move in March and April, but the precise schedule and their routes have not been determined. Fall migrants begin to depart in late summer and continue to move well into November. Rails breeding farther north migrate earlier. Migration occurs at night and probably at low altitudes.

  • unknown
  • unknown
  • Subspecies Endangered
Population Status Trends

In the mid 19th Century, John James Audubon reported this rail as "exceedingly abundant." In recent times, total population numbers have been impossible to calculate, but nowhere is it "exceedingly abundant." Breeding Bird Surveys (BBS) and Christmas Bird Counts are not well-designed for counting secretive marsh birds. Between 1966 and 2006, these surveys show little to no increase in populations, but the BBS indicates that its data are not statistically significant.

The 3 Endangered subspecies have been tracked more closely and specifically. In California, 277 pairs of the Light-footed Clapper Rail were estimated in 1984. By 1990, the total population was estimated at 380 pairs, including the Mexican population. In 2007, the total population is believed to be fewer than 1,000.

Once common, the California Clapper Rail has not recovered its numbers since market hunting in the late 19th Century. In the mid-1970's, about 5,000 California Clapper Rails resided around San Francisco Bay. By the mid-1980's that number had dwindled to about 1,000 and continued to fall to less than 400 individuals in 1992. In 2007, the total population is believed to be fewer than 1,000.

In the U.S., numbers of Yuma Clapper Rails have fluctuated between 503 and 885, from 1996 to 2005. In Mexico, the estimated population dropped from 6,300 in 1999 to 4,850 in 2003.

Conservation Issues

The Clapper Rail suffers from ongoing habitat loss and fragmentation, increased predation caused by human activities, and the invasion of its habitat by exotic plant species. Between 1780 and 1980, states that host the Clapper Rail have lost between 30 and 91% of their total wetlands. Some coastal marshes have suffered severely. The San Francisco Bay area has lost over 90% of its original 193,800 acres of tidal marshes, the only remaining habitat for the Endangered California Clapper Rail. In 2006, the U.S. Department of the Interior reported a loss of over 28,000 acres of the country's intertidal wetlands between 1998 and 2004. Agriculture, mosquito control, housing development, recreation, and increased fresh water runoff laden with pollutants and silt destroy, degrade, and fragment our salt marshes. Habitat fragments may support rails but they also expose them to more predators and offer less food.

The Endangered Clapper Rail subspecies have recovery plans, produced in the 1970's and 1980's, which need updating.

Specific conservation actions have benefited the California Clapper Rail, including the creation of the San Francisco Bay National Wildlife Refuge, including over 40,000 acres of marshland. On the refuge, Blair Island is now being restored. Between 2004 and 2007, over 15,000 pounds of invasive plants and 3,000 pounds of garbage have been hauled out this section. Restored marshes in which the rails can forage need to be large, globular (not narrow), surrounded by a thick transitional border, close to other marshes, and fed by many tidal channels,.

In 2006, the 5 Year Review for the Yuma Clapper Rail noted that little has been done to increase its population, but that its needs are better understood. The review calls for water level management to protect existing wetlands in the Lower Colorado River Valley, the restoration and creation of marshes, and a reliable water flow from the United States into Mexico to sustain the marshes at Cienega de Santa Clara.

Little has been done for the Endangered Light-footed Clapper Rail or for the eastern populations.

What You Can Do

Look for the Clapper Rail in late summer or early fall in the coastal marshes. A boardwalk at a state park or wildlife refuge can offer the best viewing, especially at high or extremely low tide.

Support the Endangered Species Act and the designation of Critical Habitat for Endangered species. Listing under the Endangered Species Act made it possible to learn critical information about the biology of the Yuma Clapper Rail. Audubon continues to work to ensure that this vital legislation protects our publicly-owned wildlife resources. Learn of the latest news about the Endangered Species Act and how you can help at Audubon's Issues & Action web pages.   Join the effort to restore North America's wetlands. Organizations like Save the Bay  in San Francisco have a history of successful restoration and community activism. They need volunteers to clean, replant, and monitor wetlands. 

Find out about actions you can take including Audubon programs and activities.

More Information

Learn more about other species protected under the Endangered Species Act.

Learn more about this species and other birds through these resources

.

Natural History References

Eddleman, W. R., and C. J. Conway. 1998. Clapper Rail (Rallus longirostris). In The Birds of North America, No. 340 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

Sibley, David Allen. 2000. The Sibley Guide to Birds. Alfred A. Knopf, New York.

Conservation Status References

Albertson, J. 1998. Restoring salt marsh habitat for the recovery of California clapper rails. Tidelines. U. S. fish and Wildlife Service. Don Edwards San Franciso Bay National Wildlife Refuge. Newark, CA. Accessed 7 September 2007. 

Dahl, T. E. 2006. Status and Trends of Wetlands in the Conterminous United States 1998 to 2004. U. S. Department of the Interior; Fish and Wildlife Service, Washinton, D. C. 112 pp.

Eddleman, W. R., and C. J. Conway. 1998. Clapper Rail (Rallus longirostris). In The Birds of North America, No. 340 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

MANEM Waterbird Working Group. Waterbird Conservation Plan for the Mid-Atlantic/New England/Maritimes Region: 2006-2010. December 2006. Waterbird conservation for the Americas. Accessed 5 September 2007.

NatureServe. 2007. Clapper Rail. NatureServe Explorer: An online encyclopedia of life. Version 6.2. NatureServe, Arlington, Virginia. Accessed: September 5, 2007. 

Fitzpatrick, Lesley. Yuma Clapper Rail 5-Year Review – 2006. Notice 70 FR 5460-5463. U.S. Fish and Wildlife Service, Southwest Regional Office. Accessed 5 September 2007.