Getting Our Ducks in a Row

Found nowhere else on Earth, the koloa maoli or Hawaiian Duck, has been in the Hawaiian Islands for at least 10,000 years.
Genetic studies and fossil records suggest that koloa are an ancient hybrid of Mallard and the koloa pōhaka or Laysan Duck, Hawaiʻi’s other endemic duck.
In the mid-1800s, koloa were common throughout the Islands and hunted for sport. By the 1950s koloa were present only on O‘ahu, Kaua‘i, and Ni‘ihau.
In addition to hunting, the loss of Hawaiʻi’s wetlands for development contributed to the koloa’s decline, as well as the introduction of mongooses and feral cats.
Only about 700 koloa remain in the wild. Most are on Kauaʻi with a small number on Hawaiʻi Island.
A critical threat to the remaining koloa are Mallard imports, brought to Hawaiʻi in the late 1800s for farming and stocking ornamental ponds.
When a wild Mallard and koloa mate, they produce fertile, hybrid offspring. Some look like koloa and some look like Mallards.
Pure koloa are darker brown and 20-to-30 percent smaller than Mallards. Koloa males, females, and hybrids resemble female Mallards. Pure male Mallards have a white neck ring.
Males and females of both species have an iridescent green-blue patch on their secondary wing feathers. The patches are often hidden behind the ducks’ longer primary flight feathers.
Hybrids (photo below): Because it lacks the Mallard’s white neck ring, this male duck (left) is a hybrid of a koloa and a Mallard. The female is also a hybrid. (Female Mallard’s bills are orange and black.)

Cart

Getting Our Ducks in a Row