Hawaiian Coot

Fulica americana alai

Description

The Hawaiian coot, Fulica americana alai, is a sub-species of the American coot, a common North American waterbird. The Hawaiian coot is smaller in body size, 13-16 in 33-40.6 cm) in length, and has dark slate-gray plumage and conspicuous white undertail feathers. The bill extends up the front of the head to form a prominent white frontal shield. This frontal shield is red in about 15% of Hawaiian coots. The sexes are alike in appearance. This bird is known by the Hawaiian name "alae ke'o ke'o."

Behavior

The coot nests in ponds, reservoirs, irrigation ditches, and openings among marsh vegetation. Nesting occurs mostly from March through September and appears to be triggered by local habitat conditions, such as water levels. Some breeding occurs year round. The coot builds its nest from aquatic vegetation, anchoring it to clumps of emergent plants. Nests may occasionally be free floating. Clutch size averages between four to six eggs, while incubation lasts from 23 to 27 days. Chicks leave the nest soon after hatching. Coots often build additional false nests near the actual nest and use these as loafing or brooding platforms. Coots prefer to feed close to nests but will fly long distances when food is scarce locally. They dive for food or forage in mud and sand, feeding on seeds and leaves of aquatic plants, snails, crustaceans, small fish, tad-poles, and insects. In general, coots are noisy and aggressively territorial. The male reacts first to drive other coots away, but in his absence the female will confront intruders. Confrontation sometimes leads to outright violence. Coots rapidly charge across the water with wings flapping and attempt to upend an intruder by rearing back, grabbing at the neck with one clawed foot and striking out with the other, all the while making sharp jabs with the bill. The winner of the contest will then attempt to hold the other bird under water. This sharply antisocial behavior explains the colloquial use of old coot to describe a misanthropic person. Social conflict, however, is tempered by the coot's large repertoire of displays employed to communicate non-hostile intentions. It signals with body posturing, the positioning of tail feathers or wings, and the angle of the neck feathers. When aroused it can inflate its frontal shield, and when threatened by predators or human intruders, it erects its feathers to appear much larger than it is.

Habitat

Hawaiian coots inhabit a variety of freshwater and brackish wetlands, including lakes, tidal ponds, and marshes where vegetation is interspersed with open shallows. Coots generally prefer more open water than gallinules, particularly for feeding, but some plant cover is necessary for protection from predators. Coots nest only where water levels are stable and will avoid salt water. Pristine habitat may support as many as 10 coots per acre (1 acre=0.4 hectares) during the nonbreeding season. Most suitable wetlands are near the coastline below 660 ft (201.2 m) in elevation.

Distribution

This species was once found on all the larger Hawaiian Islands except Lanai and Kahoolawe, which apparently lacked suitable waterbird habitat. Coots are most numerous on Oahu, Maui, and Kauai. Censuses from the late 1950s to the late 1960s indicated a population of less than 1,000. Since then, populations gradually increased to an average of 1,840 birds, as surveyed from 1980 through 1986.

Threats

Loss of both natural and cultivated wetland sites, such as taro fields, has been the primary cause for the decline of the coot and other Hawaiian waterbirds. Once a staple of Hawaiian agriculture, wet taro fields have nearly all been replaced by dry sugarcane fields. Today only about 500 acres (202.3 hectares) of taro or other wetland crops remain on the islands. Other wetlands have been filled to construct hotels and other commercial and residential development. Encroaching non-native plants, such as California grass, water hyacinth, and mangrove, have degraded remaining wet-lands.

Conservation and Recovery

A century ago, Hawaii's endemic waterbirds were nominally protected by the law because of their role in controlling army worms, an agricultural pest. In 1952 Kanaha Pond on Maui was designated as the first state waterfowl sanctuary. In 1972 the first national wildlife refuge for waterbirds, consisting of 917 acres (371 hectares), was acquired in Hanalei Valley on Kauai. Since that time, four additional wetland refuges have been established: Huleia, along the Huleia River on Kauai; Kakahaia on Molokai; Pearl Harbor on Oahu; and the James Campbell National Wildlife Refuge on Oahu. These refuges have enabled the Hawaiian coot to stabilize its population.

Contacts

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
(503) 231-6121
http://pacific.fws.gov/

U. S. Fish and Wildlife Service
Office of Environmental Services
300 Ala Moana Boulevard
P.O. Box 50167
Honolulu, Hawaii 96850

References

Byrd, G. V. 1985. et al. "Notes on the Breeding Biology of the Hawaiian Race of the American Coot." Elepaio 45 (7): 57-63.

Ehrlich, P. R., D. Dobkin, and D. Wheye. 1988. The Birder's Handbook: A Field Guide to the Natural History of North American Birds. Simon and Schuster, New York.

Ripley, S. D. 1977. Rails of the World. David R. Godine, Boston.

Ryan, M. R., and J. J. Dinsmore. 1980. "The Behavioral Ecology of Breeding American Coots in Relation to Age." Condor 82: 320-327.

U. S. Fish and Wildlife Service. 1985. "Recovery Plan for the Hawaiian Waterbirds." U. S. Fish and Wildlife Service, Portland.

Weller, M. W. 1980. The Island Waterfowl. Iowa State University Press, Ames.