RAILS, COOTS, AND MOORHENS – Rallidae

RAILS, COOTS, AND MOORHENS

RAILS, COOTS, AND MOORHENS FACTS

Rails are usually colored to blend into their environments. Browns, blacks, grays, and blue-gray shades are particularly common in the group. One group of gallinules, however, tends to have brighter colors such as purples, blues, and greens. Rails often have spotted, barred, or streaked patterns. The underside of the tail is frequently differently colored from the rest of the animal. Generally, females and males are similarly colored, with a few exceptions such as the flufftails and some of the New Guinea forest rails.

Rails vary in size from 4.7 inches (12 centimeters) and 0.7 ounces (20 grams) for the black rail, the smallest member of the family, to 24.8 inches (63 centimeters) and 9.2 pounds (4.2 kilograms) for the takahe, a large, flightless rail species. In most rails, males and females are similar in size. However, males are much larger than females in a few species.

The bodies of rails are often laterally compressed, flattened on the sides, a trait which allows them to move easily through dense vegetation. Many species have long necks. The wings of most rails are short, broad, and rounded. An unusually large number of rails are flightless, unable to fly. These are generally species found on islands that have no natural predators, animals that hunt them for food. Even some rails that are able to fly sometimes escape danger by running away instead of flying. Some rails also have a sharp claw on the wing that helps individuals, particularly young rails, climb. Rails generally have short tails. Bills vary a lot among the rails, and may be long or short, straight or downwardly curved, and thick or thin. Bill shape depends primarily on diet. Rails have strong legs and feet. In some species the legs are rather long.

GEOGRAPHIC RANGE

Rails are found worldwide except in the Arctic and Antarctica, and in very dry deserts. They are particularly common on oceanic islands. In part, this is because of their weak flying abilities, which causes them to be easily thrown off course.

RAILS, COOTS, AND MOORHENS HABITAT

Rails live in a wide variety of habitats, including wetland, grassland, scrub, and forest. Wetlands have the largest number of rail species, although many species are also found in rainforests. Both freshwater and coastal saltwater wetlands are used by rails. Coots are the most aquatic rails and live in freshwater habitats such as lakes and ponds. Rails that live in forested areas can inhabit diverse forest types with almost any type of ground cover, either clear, with leaf litter, with mud, or covered with dense vegetation.

RAILS, COOTS, AND MOORHENS DIET

Rails are omnivorous, meaning they eat both plant and animal matter. The more aquatic rails, such as coots and gallinules, tend to eat primarily plant matter, whereas wetland and terrestrial rails tend to have a diet consisting mostly of animal matter. Animal matter eaten by rails can include insects, spiders, worms, mollusks, crustaceans, and sometimes small fish, frogs, tadpoles, lizards, snakes, or turtle hatchlings. Rails will also eat the eggs or chicks of other birds. Some rails even eat carrion, dead animal matter. Plant matter eaten by rails can include fruits, seeds, stems, leaves, tubers, roots, and, in some species, cultivated crops. Most rails are generalists, that is, they eat a wide variety of foods, concentrating on whatever food is most abundant at the time. However, there are a few specialists. The chestnut rail and rufous-necked wood-rail, for example, inhabit mangrove forests and eat mostly crabs.

BEHAVIOR AND REPRODUCTION

Most rails are solitary, meaning they live alone, although some can be found in pairs, usually male and female breeding partners, or in small groups. Some species, however, including most coots and some gallinules and moorhens, sometimes gather in large flocks during the nonbreeding season. The black-tailed native-hen, an Australian rail, can form flocks of as many as 20,000 individuals.

Breeding strategies vary across the rails. Many species are monogamous (muh-NAH-guh-mus), with one male mating with one female. Some species are polygamous (puh-LIH-guh-mus), meaning single males mate with multiple females. Other species are polyandrous (pah-lee-AN-drus), where a single female mates with multiple males. In some species, older siblings help their parents feed and care for younger siblings. Intraspecific brood parasitism is also common among the rails. This describes a strategy in which a female lays eggs in the nests of other females so that other individuals will feed and raise her young.

Many rails are territorial and will defend their territories from other individuals of the same species. To prevent serious injuries from actual fighting, territorial disputes between rails are decided using displays, characteristic postures or behaviors that help determine which individual would win in an actual fight.

Rails are shy, and generally stay in areas of dense vegetation. At night, they roost on the ground, hidden in dense vegetation, or, less commonly, in trees.

RAILS AND PEOPLE

Many species of rails have been and continue to be hunted either for food or for sport. Rail eggs are also sometimes collected and eaten. Some species of rails are considered pests because they damage crops. The purple swamphen appears in Egyptian wall paintings and was also considered sacred by the Greeks and Romans.

CONSERVATION STATUS

Of the 134 rail species in existence, thirty-three are considered threatened by the World Conservation Union (IUCN). Of these, four are Critically Endangered, facing an extremely high risk of extinction in the wild. Twelve are Endangered, facing a very high risk of extinction, and sixteen are Vulnerable, facing a high risk of extinction. One, the Guam rail, is Extinct in the Wild. No fewer than twenty rail species have become extinct since 1600, the majority of them flightless species on islands. Threatened species have suffered population declines due primarily to habitat destruction. Some island species have also been severely affected by the introduction of animals such as cats, dogs, pigs, mongooses, and snakes.