Rallus elegansking rail

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Geographic Range

Habitat

Rallus elegans prefers permanent fresh water marshes in the Midwest, although it uses brackish wetlands elsewhere. Grasses, sedges, rushes and cattails are important cover types. They are typically found in in rice fields in the southern United States and rarely along roadside ditches. Rallus elegans is also found in coastal regions that contain salt water marshes. (Darrah and Krementz, 2009; Poole, et al., 2005)

Physical Description

Rallus elegans is a large, slender, rust-colored marsh bird with a long bill and long toes. It is the largest North American rail. Rallus elegans features an olive-brown upper body, reddish-brown breast and black-and-white barred flanks. Its tail is short and often lifted up. Females and males are similar, females generally are smaller than males. Females, on average weigh 11 to 13 ounces while males, on average, weigh 12 ounces.

Rallus elegans chicks are downy and black in coloration. They can be confused for black rails (Laterallus jamaicensis), but R. elegans have dark (not red) eyes, a white bill and lack spotting on their backs. Juveniles are similar to adults, but markings are indistinguishable with variable amounts of black on their sides.

Virgina rails (Rallus limicola) occur in the same habitats, are gray-cheeked, smaller versions of R. elegans and lack the extensive barring on the sides of R. elegans. Clapper rails (Rallus longirostris) are also similar to R. elegans in appearance, but are smaller and have dull black-and-white stripes on the flanks. ("King Rail", 2001; "Rail", 2010; Darrah and Krementz, 2009; )

  • Sexual Dimorphism
  • sexes alike
  • male larger
  • Range mass
    280 to 504 g
    9.87 to 17.76 oz
  • Range length
    38.1 to 48.26 cm
    15.00 to 19.00 in
  • Range wingspan
    53.34 to 63.5 cm
    21.00 to 25.00 in

Reproduction

Currently, all evidence suggests Rallus elegans is a monogamous species. Male Rallus elegans utilize several courtship displays to attract a mate. Male courtship behaviors include strutting with tail held vertically, exposing the white under tail coverts, tail flicking or fanning, and a "pursuit display" where the male hunches over low to the ground and follows a female. In some populations, courtship feeding has been observed where a male presents a female with crayfish or crabs. Males also give courtship calls during any display except a pursuit display. Pairs uphold a monogamous relationship throughout the breeding season, but birds become solitary during the non-breeding periods. Pair fidelity from year to year is currently unknown. (Meanley, 1957; Poole, et al., 2005)

The nesting season of Rallus elegans begins in early March and lasts until early September with the peak of activity occurring between April 15 and July 1. Nests are a platform of vegetation with a depression in the center, a canopy of nearby vegetation, and occasionally a ramp. After copulation, the female lays one egg per day into the nest. This is done until a clutch of 6 to 14 eggs is reached. The incubation period lasts an average of 22 days. Each of the young are precocial, meaning they are capable of following the mother around shortly after birth. The young's first flight occurs approximately 63 days after birth. ("King Rail, Life History", 2011; Poole, et al., 2005)

  • Breeding interval
    King rails breed once yearly.
  • Breeding season
    The breeding season for king rails occurs from April through July.
  • Range eggs per season
    6 to 14
  • Average time to hatching
    22 days
  • Average fledging age
    63 days

Both parents exhibit parental care for the young, however the female generally is present more often than the male. Rallus elegans males are aggressive defenders of their territory and will chase out other Rallus elegans males, as well as males of other rail species. Males are also the primary participants in nest construction. Both parents take turns incubating the clutch. Once the young are born, both parents still care for the young, but the female is present more often. Hatchling R. elegans are precocial at hatching, and quickly leave the nest to follow their parents and learn how to care for themselves. The young are fed by both parents from 1 to 3 weeks of age. During this time, the young learn how to gather food from watching their parents and are capable of foraging on their own at 4 to 6 weeks old. Parents remain with their brood until they are at least 30 days old. ("King Rail", 2001; ; Poole, et al., 2005)

  • Parental Investment
  • precocial
  • male parental care
  • female parental care
  • pre-fertilization
    • provisioning
    • protecting
      • male
      • female
  • pre-hatching/birth
    • provisioning
      • male
      • female
    • protecting
      • male
      • female
  • pre-weaning/fledging
    • provisioning
      • male
      • female
    • protecting
      • male
      • female
  • pre-independence
    • provisioning
      • male
      • female
    • protecting
      • male
      • female

Lifespan/Longevity

Rallus elegans typically lives 5 to 9 years in the wild. Limits to the lifespan of R. elegans include predation, farming practices, wetland destruction and impacts from vehicles. ("King Rail, Life History", 2011)

  • Typical lifespan
    Status: wild
    5 to 9 years

Behavior

Rallus elegans is a secretive marsh bird, thus little is known regarding behavior. It is a largely migratory species although some southern populations remain in the same location year-round. Rallus elegans is nearly completely diurnal, but many nocturnal behaviors have been reported during the breeding season.

Little is known about social behaviors in Rallus elegans. Pairs form during the breeding season, and males are highly territorial at this time. Males actively chase out males of the same, or even different, species. Outside of the breeding season, it is largely thought to be solitary. Rallus elegans is also thought to be a solitary nocturnal migrant. This is largely due to its territorial nature. Flight for R. elegans is usually short and low to the ground, with their feet skimming the tops of vegetation. During the breeding season R. elegans is typically found in pairs and later found with their broods trailing in a line behind the male and female. ("King Rail", 2001; Darrah and Krementz, 2009; Poole, et al., 2005)

Home Range

Exact territory size is currently unknown, but one study found a row of 3 nests located 298 ft and 166 ft from the next. (Meanley, 1957)

Communication and Perception

Rallus elegans is a very visual and acoustic communicator. This rail relies heavily on acoustic communication to communicate with mates and other rails. Rallus elegans gives a wide variety of calls although due to it's secretive nature and dense habitat, associated behaviors are poorly understood. Most vocalizations are dry, clicking sounds mnemonically described as 'kik-kik-kik' or a rolling 'chur-ur-ur'. Amount of vocalizations increases during the breeding season, suggesting there is an important vocal element to courtship. Rallus elegans uses postures and tail movements to communicate mating interest or aggression. When pursuing a mate, male R. elegans may crouch low to the ground, flare the tail feathers or hold the tail vertically. Males also crouch to ward off territory intruders and will eventually aerially attack a persistent threat. Like most bird species, R. elegans perceives it's environment through visual, auditory, tactile, and chemical stimuli. ("King Rail, Life History", 2011; ; Poole, et al., 2005)

Food Habits

Rallus elegans is considered an omnivore, but mainly feeds on crustaceans, fish and insects. Occasionally it will feed on plants or seeds. Water is very important to R. elegans, because even if its food has come from land it will dunk it in water before consuming it. The bill and legs of R. elegans are specialized for probing and foraging in water. Common prey items include crayfish, red-jointed fiddler crabs, clams, perch, and aquatic beetles. ("King Rail, Life History", 2011; Poole, et al., 2005)

  • Primary Diet
  • carnivore
    • eats non-insect arthropods
  • Animal Foods
  • fish
  • insects
  • terrestrial non-insect arthropods
  • aquatic crustaceans
  • Plant Foods
  • leaves
  • roots and tubers
  • seeds, grains, and nuts

Predation

Rallus elegans is mostly preyed upon during the egg and juvenile stages of life. Predators of eggs and young include red fox, raccoons, mink, feral cats, and coyotes. Some adults are caught by predators such as great horned owls, northern harriers, and alligators. Rallus elegans coloration allows for it to be well camouflaged from predators. It also can puff up and flutter around in the brush to try and scare off potential predators. ("King Rail", 2001; "King Rail, Life History", 2011; Poole, et al., 2005)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Rallus elegans serves as both predator and prey in marsh ecosystems. Due to its heavy reliance on crayfish, R. elegans likely has a significant effect on local populations. (Poole, et al., 2005)

Economic Importance for Humans: Positive

Rallus elegans is considered a game bird in much of the southern United States from Texas to Delaware. Though few rails are harvested, bag limits in some states are up to 15 per day. (Darrah and Krementz, 2009; Poole, et al., 2005)

Economic Importance for Humans: Negative

There are no known negative effects of Rallus elegans on humans.

There are no known negative effects of king rails on humans.

Conservation Status

Rallus elegans is a species of concern according to the United States Fish and Wildlife Service. In many individual states, especially in the northern range such as the states of Michigan and Minnesota, R. elegans is listed as endangered. This is primarily due to human-induced habitat destruction, as wetlands are rapidly shrinking or disappearing across their range. (Poole, et al., 2005)

Contributors

Tressa Sellner (author), Minnesota State University, Mankato, Robert Sorensen (editor), Minnesota State University, Mankato, Rachelle Sterling (editor), Special Projects.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

bog

a wetland area rich in accumulated plant material and with acidic soils surrounding a body of open water. Bogs have a flora dominated by sedges, heaths, and sphagnum.

brackish water

areas with salty water, usually in coastal marshes and estuaries.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

diurnal
  1. active during the day, 2. lasting for one day.
endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

estuarine

an area where a freshwater river meets the ocean and tidal influences result in fluctuations in salinity.

female parental care

parental care is carried out by females

freshwater

mainly lives in water that is not salty.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

male parental care

parental care is carried out by males

marsh

marshes are wetland areas often dominated by grasses and reeds.

migratory

makes seasonal movements between breeding and wintering grounds

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

riparian

Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

saltatorial

specialized for leaping or bounding locomotion; jumps or hops.

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

young precocial

young are relatively well-developed when born

References

2011. "King Rail, Life History" (On-line). The Cornell Lab of Ornithology. Accessed May 01, 2011 at http://www.allaboutbirds.org/guide/King_Rail/lifehistory.

2001. "King Rail" (On-line). Michigan Natural Features Inventory. Accessed May 01, 2011 at http://web4.msue.msu.edu/mnfi/abstracts/zoology/Rallus_elegans.pdf.

2010. Rail. Pp. 1 in Columbia Electronic Encyclopedia, Vol. 1, 1 Edition. Online: Columbia Electronic Encyclopedia. Accessed May 01, 2011 at http://web.ebscohost.com.ezproxy.mnsu.edu/ehost/detail?vid=2&hid=9&sid=674c860c-54d9-4859-8957-b33b5a949e8a%40sessionmgr14&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d.

Darrah, A., D. Krementz. 2009. Distribution and Habitat Use of King Rails in the Illinoirs and Upper Mississippi River Valleys. Journal of Wildlife Management, 8: 1380-1386. Accessed May 01, 2011 at http://web.ebscohost.com.ezproxy.mnsu.edu/ehost/detail?sid=814c9353-7fac-4260-be9f-2f3c78e3978e%40sessionmgr15&vid=1&hid=9&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d.

Meanley, B. 1957. Notes on the courtship behavior of the king rail. The Auk, 74: 433-440.

Poole, A., L. Befier, C. Marantz, B. Meanley. 2005. "Birds of North America Online" (On-line). King Rail (Rallus elegans). Accessed May 01, 2011 at http://bna.birds.cornell.edu/bna/species/003.