Hawaiian Duck

From Wikipedia, the free encyclopedia

This article may need to be wikified to meet Wikipedia's quality standards.
Please help improve this article, especially its introduction, section layout, and relevant internal links. (help)

iHawaiian Duck

Conservation status

Endangered (EN)

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Anseriformes
Family:	Anatidae
Genus:	Anas
Species:	A. wyvilliana

Binomial name

Anas wyvilliana
Sclater, 1878

The Hawaiian Duck (Anas wyvilliana) is a species of the genus Anas. It is endemic to the islands of Hawaii. The former range of the Hawaiian Duck included all of the main Hawaiian islands except the island of Lana'i. Now the Hawaiian Duck only exists on the island of Kaua'i. The Hawaiian Duck was exterpirated on all other islands, but was subsequently reestablished on Oahu, Hawaii, and Maui through release of captive-reared birds. However, all the Hawaiian Ducks in the reestablished populations have bred with feral Mallard ducks and have produced hybrid chicks. So the only pure Hawaiian Ducks exist on the island of Kaua'i. Some authorities treat the Hawaiian Duck as an island race of the Mallard duck. The Hawaiian name for this duck is the Koloa. Males, (19-20"), are bigger than females, (16-17"). Both sexes are mottled brown in color. This motled brown color resembles a dark female mallard. The speculum is green to blue, bordered on both sides by white. The tail is dark, unlike the white tail of a mallard. The adults male has a darker head and neck which is also sometimes green. A first-year male Koloa looks like an eclpse-plumaged male Mallard. The feet and legs of the Koloa are orange. The bill is olive green in the male and dull orange with dark markings in the female. Another difference between the Koloa and the Mallard is their vocalizations. The Koloa quacks like a mallard, however not as harsh and vocal. Instead, the Koloa's quack is softer than a mallards. The Koloa is very wary and is often found in pairs. They can be found in lowland wetlands, river valleys, and mountain streams. The Koloa's diet consists of freshwater vegitaion, mollusks, and insects. Some Koloas nest year round, but their primary breeding season is from December to May. During the breeding season, pairs are often engaged in spectacular nuptial flights. Two to ten eggs are laid in a well-concealed nest lined with down and breast feathers. When first hatched, the young can soon take to the water, but cannot fly for nine weeks. Threats to the Koloa include feral cats, rats, and mongeese which eat the eggs and young of the Koloa. Genetic reaserch has also proven that interbreeding with feral mallards threatens the genetic integrity of the Koloa species^{[citation needed]}.

[edit] References

BirdLife International (2006). Pterodroma sandwichensis. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 10 May 2006. Database entry includes a brief justification of why this species is vulnerable and the criteria used
(2005). Hawaii's Birds. Hawaii Audubon Society. Sixth ed.