Laysan ducks introduced on Midway
Advertiser Staff
A flock of endangered Laysan ducks is being established at the Midway Atoll National Wildlife Refuge, about 1,250 miles northwest of Honolulu.
The 20 young ducks were captured on Laysan island in the Northwestern Hawaiian Islands by scientists and taken on a
two-day boat ride to their new home, arriving Oct. 3. U.S. Fish & Wildlife Service spokesman Ken Foote said yesterday that the birds are gaining weight and adapting well to their new environment.
The Laysan duck, whose scientific name is Anas laysanesis, had the smallest geographical range of any duck species in the world, with approximately 500 birds living on Laysan. It is one of only two endemic duck species still found in Hawai'i, the other being the Hawaiian duck or koloa.
Anas laysanesis was believed to have existed only on Laysan, until evidence from bones in 1995 indicated it once inhabited the Big Island, Moloka'i, Maui, O'ahu and Kaua'i.
Laysan ducks, between 15 and 17 inches in length, are brown with bright blue-green to purple feathers on their secondary wing feathers. They have a small patch of white around their eyes, and orange legs and feet. They are primarily insect feeders, but also eat leaves and seeds.
Because the ducks were located in a single habitat, they were vulnerable to extinction, so biologists felt that creating a second population would increase chances of its recovery. Foote said Midway was chosen as a reintroduction site because it lies within the duck's presumed former range, is free of rats and other predators, and provides good logistics for monitoring the flock.
A team of project scientists from the Fish & Wildlife Service, the U.S. Geological Survey and the Pacific Island Ecosystem Research Center studied the relocation candidates in the wild on Laysan for six months before capturing 27 ducks. Of that group, 20 were selected for the transfer.
In anticipation of the ducks' arrival, Fish & Wildlife staff and volunteers spent 18 months removing nonnative ironwood trees and verbesina plants, excavating nine shallow fresh-
water seeps, and providing 1,400 native bunch grass plants for nesting. Once they arrived, the ducks were placed in aviaries while awaiting release. Radio transmitters were attached to each bird for tracking.
Humans came to live on Laysan in the 1890s to mine guano. They killed an estimated 300,000 birds within six months and introduced rabbits that devastated the vegetation, leading to the extinction of three bird species: the Laysan rail, the Laysan honeycreeper and the Laysan millerbird.
In 1911, records showed that there were only 11 Laysan ducks left.
