| Hawaiian Duck | |
|---|---|
 female | |
 male | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Anseriformes |
| Family: | Anatidae |
| Genus: | Anas |
| Species: | A. wyvilliana |
Although similar in appearance to the Mallard Duck of the mainland, the Hawaiian Duck (Anas wyvilliana) is actually a distinct species endemic to the Hawaiian Islands.
Appearance[]
Both sexes resemble a dark female mallard; mottled brown plumage with blue speculums bordered on both sides by white. Males are larger than females, growing up to 20 inches while females are typically in the range of 16-17 inches long. Adult males have darker head and neck feathers and have olive green bills. Females have a dull gray or orange bill with a "saddle". In box sexes, the feet and legs are orange.
Habitat and Range[]
The Hawaiian Duck once inhabited all of the main islands of Hawaii except Lana'i and Kaho'olawe. Wild populations are now restricted to Kaua'i and Ni'ihau and small populations have been reestablished on O'ahu, Big Island, and Maui.
Koloa maoli inhabit coastal wetlands, river valleys, freshwater pools, bogs, streams, and marshy areas. They prefer shallow water with dense cover and safe roosting sites, often in the form of islands, nearby.
Diet[]
Koloa feed on the leaf parts and seeds of a variety of wetland plants, crustaceans, insects, nematodes, and algae. They can often be seen feeding in taro fields.
Behavior[]
Hawaiian Ducks are very secretive and as a result, difficult to observe. These ducks do not normally associate with wintering or feral mallards despite the inbreeding between the two species.
Vocalizations[]
Hawaiian Ducks are capable of quacking like a mallard, but prefer to vocalize less.
Reproduction[]
Some Hawaiian Ducks nest year-round, through the primary breeding season is from December to May. Koloa build their well-concealed nests on the ground near water, lining them with down and breast feathers. Two to ten eggs are laid and incubated for less than a month. The young are precocial, able to take to water soon after hatching but are unable to fly for about nine weeks.
Ecological Threats[]
Feral mallards are noroiously effective breeders and will interbreed readily with species distantly related. Koloa and mallard hybridization has been threatening the existence of pureblooded Koloa. Other factors include habitat loss, altered hydrology, alien plant enraochment, avian botulism, and introduced mammalian predators. Invasive predators such as the mongoose, cats, dogs, Black-crowned Night Herons, and Common Mynas will prey on ducklings. Pureblooded Hawaiian Duck populations are largely concentrated on Kauai, an island where vigilant efforts to reduce mallard populations to a number far smaller than the Hawaiian Duck population has succeeded. To further reduce Mallard populations, the Division of Forestry and Wildlife of the State of Hawaii enourages people not to feed mallard ducks and not release domesticated ducks into the wild.
The Hawaiian Duck is listed as Endangered by the Federal and State governments. It is protected under the Migratory Bird Treaty Act.
Cultural Significance[]
Hawaiian Ducks were said to be a guide to the mythical blind warrior king Imaikalini. The ducks would altert Imaikalini of the presence of his enemies whenever he went to battle and guide his spears to his target.
Works Cited[]
"Hawaiian Duck." Marines, www.mcbhawaii.marines.mil/. Accessed 18 Sept. 2022.
"KOLOA MAOLI (HAWAIIAN DUCK)." Honolulu Zoo Society, www.honoluluzoo.org/.
Accessed 18 Sept. 2022.
"KOLOA MAOLI: THE HAWAIIAN DUCK." Division of Forestry and Wildlife: Wildlife
Program, dlnr.hawaii.gov/. Accessed 18 Sept. 2022.