Gray-necked wood-rails ( (Stotz, et al., 1996)) are widely distributed throughout the Neotropical region. These birds are found in the Pacific arid slope, from southern Sonora, south to Guanacaste, as well as Costa Rica, on islands in the southern Caribbean, such as Trinidad and Tobago, west of the base of the Andes Mountains, as well as the eastern parts of Brazil, Bolivia and Paraguay. They are found as far north as the eastern slope lowlands, from the border of the United States and Mexico to the Colombian border of Panama and as far south as the southeastern part of Brazil.
Gray-necked wood-rails are found in four distinct habitats, including three types of forest. These birds are commonly found in flooded tropical evergreen forests, which are flooded either permanently or annually. Less often, (Stotz, et al., 1996)are found in gallery forests, which are also quite damp, swampy environments occurring along bodies of water. Likewise, also inhabits freshwater marshes, which have less dense vegetation than their forest habitats. Gray-necked wood-rails are also occasionally found in mangrove forests, which border lagoons, estuaries and rivers along the Pacific coast and are also flooded either permanently or occasionally.
In forest vegetation these birds are usually found in lower tropical elevation zones (lower than 500 m), but can be found as high as 1,200 m. On rare occasions, (Stotz, et al., 1996)have been found on mountains, in elevation as high as 2,300 m.
- Terrestrial Biomes
- Range elevation
- 2,300 (high) m
In general, rails have relatively thin bodies; this helps them move through dense vegetation. As their common name suggests, gray-necked wood-rails can be distinguished from other rails by their distinct gray neck and head. has a powerful, yellow bill, red eyes and long red legs. The upper parts of their feathers are olive-brown, while their rump, tail and vent are black. Their breast and flanks are brownish-red, like rust. Their average length is 38 cm. Unlike some of its relatives, this bird is flighted due to its large pectoral muscles. Males and females are indistinguishable by their physical characteristics. ("Grey-necked Wood-rail Aramides cajaneus", 2012; Garrigues and Dean, 2007; Gosler, 2007; McNab, 1994; Skutch, 1994)
- Sexual Dimorphism
- sexes alike
- Average mass
- 397 g
- 13.99 oz
- Average length
- 38 cm
- 14.96 in
- Average basal metabolic rate
- 276 cm3.O2/g/hr
In an observational study of a pair of gray-necked wood-rails, a male and female bird occupied their nest at different times of day during the incubation period, which suggests a monogamous mating system. In general, most rails are thought to be monogamous. (Harris, 2009; Skutch, 1994)
- Mating System
Breeding begins during the first part of the rainy season, spanning from April to August. Most of what is known about their reproductive behavior is derived from a few anecdotal observations. In one such observation of nesting birds in the wild, one bird left the nest after an incubating session of between 6 to 8 hours and shortly thereafter, another bird took its place on the eggs, which was assumed to be the partner. During an observation in an aviary, the male incubated during the day and the female incubated at night. Data from both the aviary and the wild suggests that the incubation period is at least 20 days. In one study, the juveniles remained with their parents until at least 53 days old. (McNab and Ellis, 2006; Skutch, 1994)
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- Breeding interval
- Gray-necked wood-rails breed once yearly.
- Breeding season
- Gray-necked wood-rails breed April to August.
- Range eggs per season
- 2.0 to 7.0
- Average eggs per season
- Average time to hatching
- 20 days
- Average fledging age
- 53 days
During the 53 days a juvenile spends with its parents, there is a great deal of parental investment, with one parent brooding at a time. As with incubation, parents share brooding responsibilities. The brooding parent brings food, carried inside their mouth or throat. A few days after the young hatch, the chicks are brought to a "nursery nest", until they are about 40 days old. Both males and females physically lure predators away from their eggs or nest. (Skutch, 1994)
Their estimated lifespan is about 3.7 years in the wild. ("Grey-necked Wood-rail Aramides cajaneus", 2012)
- Average lifespan
- 3.7 years
- Average lifespan
Observations during breeding season found only one male and one female in any given area, indicating that rails, gray-necked wood-rails are flighted. They can also be distinguished from other rails by their distinct song. (McNab, 1994; Skutch, 1994)is a solitary species. Unlike many other species of
- Average territory size
- 13,600,000 km^2
There is no information available on their home range.
Communication and Perception
- Communication Channels
maize and they are also avid frugivores. To eat these fruits, gray-necked wood-rails throw their whole bodies into pecking, see-sawing up and down, using their legs. Gray-necked wood-rails have also been observed eating water snakes and snails (Pomacea flagellata). They are also insectivorous and molluscivorous. (McNab and Ellis, 2006; Skutch, 1994)is an omnivorous bird. In their natural habitat, they have been seen eating
- Primary Diet
- Animal Foods
- aquatic crustaceans
- Plant Foods
- seeds, grains, and nuts
- Known Predators
- Humans (Homo sapiens)
Economic Importance for Humans: Positive
Adults and juveniles taken from the wild are used as both pets and food. Gray-necked wood-rails are pets both locally and internationally, while their use as food is primarily limited to their native areas. ("Grey-necked Wood-rail Aramides cajaneus", 2012; Nishizawa and Uitto, 1995)
Economic Importance for Humans: Negative
There are no known adverse effects of humans.on
There are eight subspecies of gray-necked wood-rails, although they are not usually referred to specifically in the literature, they are worth noting. The subspecies are characterized by their geographic locations. The eight subspecies are: Aramides cajanea mexicanus, Aramides cajanea albiventris, Aramides cajanea vanrossemi, Aramides cajanea pacificus, Aramides cajanea plumbeicollis, Aramides cajanea latens, Aramides cajanea morrisoni, and Aramides cajanea cajanea. (Clements, 2007)
Marissa Falkiewicz (author), The College of New Jersey, Matthew Wund (editor), The College of New Jersey, Leila Siciliano Martina (editor), Animal Diversity Web Staff.
living in the southern part of the New World. In other words, Central and South America.
uses sound to communicate
Referring to an animal that lives in trees; tree-climbing.
- 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.
uses smells or other chemicals to communicate
to jointly display, usually with sounds, at the same time as two or more other individuals of the same or different species
to jointly display, usually with sounds in a highly coordinated fashion, at the same time as one other individual of the same species, often a mate
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.
- female parental care
parental care is carried out by females
A substance that provides both nutrients and energy to a living thing.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
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
marshes are wetland areas often dominated by grasses and reeds.
Having one mate at a time.
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.
an animal that mainly eats all kinds of things, including plants and animals
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- pet trade
the business of buying and selling animals for people to keep in their homes as pets.
- seasonal breeding
breeding is confined to a particular season
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
Living on the ground.
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
uses sight to communicate
- young precocial
young are relatively well-developed when born
2012. "Grey-necked Wood-rail Aramides cajaneus" (On-line). Accessed October 10, 2012 at http://www.birdlife.org/datazone/speciesfactsheet.php?id=2884&m=1.
Clements, J. 2007. The Clements Checklist of Birds of the World. Ithaca: Cornell University Press.
Garrigues, R., R. Dean. 2007. The Birds of Costa Rica. Ithaca: Comstock Publishing Associates.
Gosler, A. 2007. Birds of the World: A Photographic Guide. Buffalo: Firefly Books Inc.
Harris, T. 2009. Complete Birds of the World. Washington D.C.: National Geographic.
McNab, B. 1994. Energy conservation and the evolution of flightlessness in birds. American Naturalist, 144/4: 628-642.
McNab, B., H. Ellis. 2006. Flightless rails endemic to islands have lower energy expenditures and clutch sizes than flighted rails on islands and continents. Comparative Biochemistry & Physiology Part A: Molecular & Integrative Physiology, 145/3: 295-311.
Nishizawa, T., J. Uitto. 1995. The Fragile Tropics of Latin America. Tokyo: United Nations University Press.
Skutch, A. 1994. The gray-necked wood-rail: habits, food, nesting, and voice. The Auk, 111: 200.
Stotz, D., J. Fitzpatrick, T. Parker III, D. Moskovits. 1996. Neotropical Birds: Ecology and Conservation. Chicago: The University of Chicago Press.