This Week in Nature: The 4th week in December - Koloa maoli

What's Happening in Hawaii 

during the 4th week in December:

 
Koloa maoli
Photo courtesy of USDA NRCS

Koloa maoli, the Hawaiian duck, (Anas wyvilliana) can now be seen making vertical flights that indicate the onset of mating. Courting pairs fly virtually straight up from ground level to an altitude of one hundred feet and chase one another in tight circles. Sometimes a second male joins the chase, trying to approach the female, but is ritually driven off. Courtship resumes on the ground, where eventually as many as ten eggs will be laid and hatched in a large, well-concealed nest. Koloa appear to mate throughout the year, but their main breeding period begins in December.

Once plentiful on most of the main islands, koloa is now an endangered species, and is fighting for survival against threats like predation by foreign animals, draining and filling of marshes, and breeding with feral and domesticated mallards.

Koloa maoli means "indigenous duck," distinguishing this native from six North American species that visit the islands in the winter. The only other native duck is a resident of Laysan, toward the northwest end of the archipelago.

To learn more about koloa maoli, visit the Comprehensive Wildlife Conservation Strategy koloa fact sheet. 

For lessons and activities about the native Hawaiian duck, visit Malama Hawaii's koloa webpage.

Taken from "Hawaii: A Calendar of Natural Events"

published by the Bishop Museum and Kamehameha Schools in 1989