Endangered Hawaiian Duck

Sightings of Duck on Molokai, first in 115 Years.

Two recent sightings of the endangered Hawaiian Duck, also known as Koloa maoli, has caused a stir in the scientific community. Photo courtesy of Michael Walther, Oahu Nature Tours.

The last observation of a Hawaiian Duck on Molokai was in May and June of 1893, so the presence of two over the past several months has caused quite a stir in the scientific community. The endemic Hawaiian Duck (Anas wyvilliana) or Koloa maoli, is a federally endangered species, with only about 2,000 “true” Koloa remaining.

Unlike other species of Hawaii’s endangered avifauna, it is not habitat loss that poses the greatest threat for this delicate dabbling duck, but genetic extinction from hybridization (cross-breeding) with feral Mallards.

Koloa utilize habitats from coastal wetlands to ponds at 10,000’ elevation, and are known to skillfully maneuver mountain streams and forest canopy. Little else, however, is known about this endangered species, and future research efforts are focused on range, behavior, and the extent of hybridization with feral Mallards.

Scientists at the University of California at Davis and the U.S. Geological Service are studying ways to differentiate pure Koloa from those that have hybridized, and how to prevent the extinction of Hawaii’s Koloa population.

The Mallard was placed on the State of Hawaii’s List of Restricted Animals for importation in the 1980s, however these domestic ducks are often sold within the state and are commonly found released on golf course or public ponds.

Don’t leave the responsibility of saving Hawaii’s endangered Koloa to the scientists… help prevent the Koloa’s hybridization with feral Mallards by being a responsible owner of any domestic duck. Keep ducks penned, pinioned, or clipped, so that they do not leave your property, and do not import, buy, or sell Mallards or their eggs, or release Mallards into the wild.

For a Fact Sheet on how the Koloa is threatened by feral Mallards, visit http://pubs.usgs.gov/fs/2007/3047/