Limpkins (Aramidae)

views updated

Limpkins

(Aramidae)

Class Aves

Order Gruiformes

Suborder Grues

Family Aramidae


Thumbnail description
Medium-sized wading birds with a long down-curved bill, long legs, long neck, rounded wings and tail, an erect stance, and a distinctive limp-like gait; brownish plumage is streaked and spotted with white

Size
26 in (66 cm); wingspan 40 in (102 cm); up to 2.4 lb (1.1 kg)

Number of genera, species
1 genus; 1 species

Habitat
Tropical and subtropical wetlands and lake and river margins

Conservation status
Many local populations are declining, but the species is not threatened.

Distribution
Florida, Mexico, Central America, tropical and subtropical South America

Evolution and systematics

The limpkin (Aramus guarauna) is the only member of the family Aramidae (which was described by Bonaparte in 1842). Limpkins are related to and intermediate in morphology and behavior to the cranes (family Gruidae) and rails (family Rallidae).

Physical characteristics

Limpkins are medium-sized wading birds with an erect stance, long legs, spreading toes, an elongate down-curved bill, and rounded wings and tail. The body length is about 26 in (66 cm), the wingspread 40 in (102 cm), and the weight is up to 2.4 lb (1.1 kg). The plumage is dark brown with white spots on the lower neck, breast, and outer wings. There is little physical difference between male and female limpkins.

Distribution

Limpkins range widely in tropical, subtropical, and warm-temperate regions of the Americas, from the southeastern United States (mostly on the Florida peninsula), through some islands of the West Indies, much of Mexico, Central America, and most of South America east of the Andes as far south as central Argentina.

Habitat

Limpkins inhabit a wide range of brushy and forested shallow-water wetlands, including the marshy edges of ponds, lakes, and slow-flowing rivers. They usually roost in shrubs or in the top of dead trees.

Behavior

Limpkins may live a solitary life or occur in breeding pairs or in small loose groups. They are difficult to see when roosting quietly in dense shrubbery but do not hide when active, especially while searching for food. In this respect their behavior is closer to that of cranes rather than to that of the much shyer rails. Limpkins can swim well. They fly slowly with an outstretched neck and with wings rising and

falling in a deliberate rhythm. The name limpkin comes from the bird's walking gait, which is somewhat awkward and resembles a limp. Limpkins are nonmigratory over much of their range, but in parts of South America they may move between habitats used during the wet and dry seasons. Limpkins have an unmistakable, loud, discordant, wild-sounding scream or wail, as well as a quieter clicking sound. Their shrill cries are most often heard in early morning, at night, or on heavily clouded days. Their calls have earned limpkins several colloquial nicknames, such as wailing bird, crying bird, and crazy widow.

Feeding ecology and diet

Limpkins feed almost exclusively on large freshwater mollusks known as apple snails (genus Pomacea). Limpkins find these snails in shallow water by searching visually and by probing carefully on the muddy bottom using their long bill. They extract the snail meat and leave an empty shell. Young limpkins take small snails from the bill of the parent and swallow them with the shell intact. Limpkins also eat mussels, insects, crayfish and other aquatic crustaceans, worms, small reptiles, frogs, and plant seeds.

Reproductive biology

A pair of limpkins builds a nest near water, either on the ground within dense vegetation or in a bush or tree 20 ft (6m) or sometimes higher above the ground. The nest is a platform constructed of reeds and grasses and lined with finer plant fibers. The female lays from four to eight eggs, each measuring about 2.2 in long by 1.7 in wide (56 mm × 44 mm) and ranging in color from whitish to pale brown with brown and gray spots. The incubation period is not exactly known. Both parents tend the eggs, and both parents cooperate in the care of their young, which are dark brown, downy, and precocial (capable of leaving the nest within about a day after birth).

Conservation status

Limpkins are not listed as being at risk globally by the IUCN or in the United States by the U.S. Fish and Wildlife

Service. Limpkins are, however, designated a species of special concern by the state of Florida. At the turn of the twentieth century, limpkins were hunted almost to extirpation in the United States, mostly as a source of meat. Since then limpkins have been protected and their populations have substantially recovered. However, many of the wetland areas inhabited by limpkins have been destroyed or degraded by filling, dredging, pollution, and other human influences. Habitat degradation has caused the species to decline in overall abundance in the last few decades of the twentieth century and to disappear from local parts of its range.

Significance to humans

Limpkins are not often hunted anymore. They are appreciated by birders and other naturalists, which can contribute to local economic benefits through ecotourism. The wailing cries of limpkins make them of cultural significance to aboriginal peoples who inhabit remote parts of the species' range.


Resources

Books

Bryan, D.C. "Family Aramidae (Limpkin)." In Handbook of the Birds of the World. Vol. 3. Hoatzin to Auks, edited by J. del Hoyo, A. Elliott, and J. Sargatal. Barcelona: Lynx Edicions, 1996.

Eckert, A.W. The Wading Birds of North America (North of Mexico). New York: Weathervane, 1981.

Nesbitt, S.A. "Limpkin." In: Rare and Endangered Biota of Florida: Birds, edited by H.W. Kale, II. Gainesville, FL: University Presses of Florida, 1978.

Niemeyer, L., and M. Riegner. Long-Legged Wading Birds of the North American Wetlands. Mechanicsburg, PA: Stackpole Press, 1993.

Stevenson, H.M., and B.H. Anderson. The Birdlife of Florida. Gainesville, FL: University Presses of Florida, 1994.

Periodicals

Snyder, N.F.R., and H.A. Snyder. "A Comparative Study of Mollusc Predation of Limpkins, Everglade Kites and Boat-Tailed Grackles." Living Bird 8 (1969): 177–223.

Organizations

BirdLife International. Wellbrook Court, Girton Road, Cambridge, Cambridgeshire CB3 0NA United Kingdom. Phone: +44 1 223 277 318. Fax: +44-1-223-277-200. E-mail: birdlife@birdlife.org.uk Web site: <http://www.birdlife.net>

Bill Freedman, PhD

More From encyclopedia.com