Limpkin

Description:

Limpkin (Aramus guarauna) - foraging and feeding, at dusk, in heavy cover - at Green Cay Wetlands, Boynton Beach, Florida. << The Limpkin is a somewhat large bird, 66 cm (26 in) long, with a wingspan of about 102 cm (40 in) and a weight of about 1.1 kg (2.4 lb). The males are slightly larger than the females in size, but there is no difference in plumage. Its plumage is drab—dark brown with an olive luster above. The feathers of the head, neck, wing coverts, and much of the back and underparts (except the rear) are marked with white, making the body look streaked and the head and neck light gray. It has long, dark-gray legs and a long neck. Its bill is long, heavy, and downcurved, yellowish bill with a darker tip. ... It inhabits freshwater marshes and swamps, often with tall reeds, as well as mangroves. ... Limpkins are largely nocturnal and crepuscular, except that in Florida refuges, where they do not fear people, they are active during the day. Even so, they are usually found near cover. ... Limpkins forage primarily in shallow water and on floating vegetation such as water hyacinth and water lettuce. >>

Habitat:

The Limpkin (also called "carrao", "courlan", "crying bird"), Aramus guarauna, is a bird that looks like a large rail but is skeletally closer to cranes. It is the only extant species in the genus Aramus and the family Aramidae. It is found mostly in wetlands in warm parts of the Americas, from Florida to northern Argentina. It feeds on molluscs, with the diet dominated by apple snails of the genus Pomacea. Its name derives from its seeming limp when it walks. The Limpkin is placed in its own monotypic family, Aramidae, which is in turn placed within the crane and rail order Gruiformes. It had been suggested that the Limpkin was close to the ibis and spoonbill family Threskiornithidae, based upon shared bird lice. The Sibley-Ahlquist taxonomy of birds, based upon DNA-DNA hybridization, suggested that the Limpkin's closest relatives were the Heliornithidae finfoots, and Sibley and Monroe even placed the species in that family in 1990. More recent studies have found little support for this relationship. More recent DNA studies have confirmed a close relationship with particularly the cranes, with the Limpkin remaining as a family close to the cranes and the two being sister taxa to the trumpeters. The Limpkin is a somewhat large bird, 66 cm (26 in) long, with a wingspan of about 102 cm (40 in) and a weight of about 1.1 kg (2.4 lb). The males are slightly larger than the females in size, but there is no difference in plumage. Its plumage is drab—dark brown with an olive luster above. The feathers of the head, neck, wing coverts, and much of the back and underparts (except the rear) are marked with white, making the body look streaked and the head and neck light gray. It has long, dark-gray legs and a long neck. Its bill is long, heavy, and downcurved, yellowish bill with a darker tip. The bill is slightly open near but not at the end to give it a tweezers-like action in removing snails from their shells, and in many individuals the tip curves slightly to the right, like the apple snails' shells. The white markings are slightly less conspicuous in first-year birds. Its wings are broad and rounded and its tail is short. It is often confused with the immature American White Ibis. The Limpkin occurs from peninsular Florida (and formerly the Okefenokee Swamp in southern Georgia) and southern Mexico through the Caribbean and Central America to northern Argentina. In South America it occurs widely east of the Andes; west of them its range extends only to the Equator. It inhabits freshwater marshes and swamps, often with tall reeds, as well as mangroves. In the Caribbean, it also inhabits dry brushland. In Mexico and northern Central America, it occurs at altitudes up to 1,500 m (4,900 ft). In Florida the distribution of apple snails is the best predictor of where Limpkins can be found. The Limpkin undertakes some localised migrations, although the extent of these are not fully understood. In some parts in the northern part of the range females (and a few males) will leave the breeding areas at the end of summer, returning at the end of winter. Birds may also migrate between Florida and Cuba. In Brazil birds breeding in some seasonal marshes will leave during the dry season and return again with the rains. Limpkins are largely nocturnal and crepuscular, except that in Florida refuges, where they do not fear people, they are active during the day. Even so, they are usually found near cover. Because of their long toes, they can stand on floating water plants. They also swim well, both as adults or as newly hatched chicks, but they seldom do so. They fly strongly, the neck projecting forward and the legs backward, the wings beating shallowly and stiffly, with a jerky upstroke, above the horizontal most of the time. Limpkins forage primarily in shallow water and on floating vegetation such as water hyacinth and water lettuce. When wading they seldom go deeper than having half the body underwater, and never are submerged up to the back. They walk slowly with a gait described as "slightly undulating" and "giving the impression of lameness or limping", "high-stepping", or "strolling", looking for food if the water is clear or probing with the bill. They do not associate with other birds in mixed-species feeding flocks, as do some other wading birds, but may forage in small groups with others of their species. The diet of the Limpkin is dominated by apple snails (Ampullariidae) of the genus Pomacea. The availability of this one mollusk has a significant effect on the local distribution of the Limpkin. Freshwater mussels, including Anodonta cowperiana, Villosa vibex, Elliptio strigosus, E. jayensis, and Uniomerus obesus, as well as other kinds of snails, are a secondary food sources. Less important prey items are insects, frogs, lizards, crustaceans and worms. These prey items may be important in periods of drought or flooding when birds may be pushed into less than optimal foraging areas. In one site in Florida moon snails and mussels were the most important prey items. Two studies, both in Florida, have looked at the percentage composition of the diet of Limpkins. One, looking at stomach contents, found 70% Pomacea apple snails, 3% Campeloma and 27% unidentified mollusc, probably Pomacea. When a Limpkin finds an apple snail, it carries it to land or very shallow water and places it in mud, the opening facing up. It deftly removes the operculum or "lid" and extracts the snail, seldom breaking the shell. The extraction takes 10 to 20 seconds. The orange-yellow yolk gland of female snails is usually shaken loose and not eaten. It often leaves piles of empty shells at favored spots. (credit: http://en.wikipedia.org/wiki/Limpkin)