Our native duck, the koloa maoli, needs our help

Few people today can say they’ve seen a Koloa maoli (Hawaiian duck), a petite and secretive bird and yet another of Hawaii’s animals on the endangered species list. Scientists estimate there are only about 2,200 individuals remaining. Not long ago, Koloa were known to have heavily populated wetlands on most islands, living in natural wetlands and taro lo‘i. They also wound their way through river corridors up into forests. Today, the strongest populations of Koloa are on Kaua‘i, Ni‘ihau, and Hawai‘i Island.

On the other islands, Koloa have been rapidly hybridizing with introduced Mallards (brought here for sport hunting, egg production, and pond beautification), which is driving the Koloa to “genetic extinction.” Hybridization occurs when a Mallard and Koloa mate and produce fertile, hybrid offspring. If this occurs generation after generation, the true Koloa will no longer exist. 

Other threats to the Koloa’s survival are habitat loss and introduced predators like dogs, cats and mongoose. But the news is not completely dire. Only 50 years ago, our state bird, the Nēnē, was down to less than 50 wild birds, and dedicated people worked hard to save it. Many people are working hard to save the Koloa from extinction, and they need our help. 

What can we do?

• Don’t feed Mallards or other feral waterbirds.

• Don’t sell or release Mallards.

• If you have Mallards, keep them penned.

• Support voluntary removal of domesticated Mallards from your property.

• Keep wetland habitats available for Koloa and other native waterbirds.

Mālama Hawai‘i is assisting biologists and resource managers in educating the public about the Koloa Maoli and threats to its survival. Short video segments have been developed and lesson plans are being field tested by teachers. You can watch the videos by clicking here.  If you would like to help educate others about this issue, please contact us at info@malamahawaii.org.

Frequently Asked Questions

What is a Koloa maoli?
Koloa maoli = native duck. Also known as the Hawaiian Duck (Anas wyvilliana), it is an endangered species found only in the Hawaiian Islands.

What does it look like?
It is a petite, dark brown duck with orange feet and bills that have yellow-green tones (males) or orange-fleshy tones (female). When they spread their wings, green to blue-purple feathers are visible. The male is slightly larger than the female. The Koloa maoli is quiet and secretive. To see one requires knowing where to look and patience.

Is the Koloa maoli the only native Hawaiian duck?
No, there are two. Koloa maoli is Hawaii’s last native duck remaining in the main Hawaiian Islands. The second native duck, critically endangered, is the Laysan Duck which is isolated on Laysan Island and Midway Atoll in the Northwestern Hawaiian Islands. A diversity of giant, flightless island waterfowl once roamed the Hawaiian Islands. They were believed to occupy the role of the dominant plant eaters in wetland and upland habitats.

What kinds of habitat do Koloa maoli live in?
Koloa maoli live in habitats mauka to makai (mountains to sea). It is found mainly in freshwater wetlands, both natural and manmade such as mountain bogs, streams, plunge pools at the bases of waterfalls, stock watering ponds, flooded pastures, taro patches and coastal wetlands. In addition to aquatic habitats, Koloa maoli use grasslands and river banks near wetlands for nesting, feeding and resting.

What do Koloa eat as part of their natural diet?
Koloa maoli are dabbling ducks, which are known to be good divers but usually feed by dabbling or tipping rather than submerging. Dabblers have bills that are specially designed to remove food particles from the water. Koloa maoli eat primarily small invertebrates such as aquatic insects, snails and immature crayfish. They also eat freshwater limu and seeds of grasses, sedges and other wetland plants.

How many Koloa maoli are left and where can I see one?
Scientists estimate that there are roughly 2,200 individuals left and they are primarily found on the islands of Kaua‘i and Ni‘ihau and some parts of Hawai‘i Island.

Why are the Koloa maoli disappearing?
The main threats to Koloa maoli are habitat loss, introduced predators and hybridization with introduced or feral Mallards, which are domesticated ducks that breed in the wild. They are considered invasive species.

What does hybridization mean?
Hybridization = cross-breeding. In the case of Koloa maoli, hybridization occurs when a feral Mallard and Koloa maoli mate and produce hybrid offspring.

What does a hybrid look like?
Hybrids can look like small Mallards, a Mallard-Koloa maoli mix or large Koloa maoli. Sometimes it is obvious, sometimes not. When viewing ducks, overall size and behavior are good cues. Male hybrids are usually larger, have a lot of green on their heads and behave differently than Koloa maoli. They are bold and not secretive. For example, hybrids and feral Mallards are common in urban and park ponds, travel in large flocks and behave like domestic ducks; Koloa maoli are more common in remote wetlands and streams where there are few people, traveling alone, in pairs, or in small flocks, and they behave like wild ducks.

How you can you tell a hybrid from a pure Koloa?
Even the experts have trouble telling the difference because hybrid size and plumage varies greatly. Some of the main characteristics are weight, amount of green on the head and gray on the flanks (males) and wing measurements. Scientists are using DNA analysis to best determine a Koloa maoli from a hybrid.

Why is hybridization with feral Mallards such a problem?
Hybridization is leading to the extinction of Koloa maoli. We have already lost Koloa maoli on O‘ahu and Maui where there are few, if any, left. True Koloa maoli are believed to exist only on Kaua‘i, Ni‘ihau and parts of Hawai‘i Island.

What is being done to help and is it really possible to save them?
Yes, it is possible to save the Koloa maoli from extinction. The 3 main “help” categories are:

1. Policies - There are changes being proposed to make laws that prevent the spread of invasive Mallards and protect Koloa maoli;

2. Biologists and managers are working together to develop methods to identify and humanely remove invasive Mallards and hybrids; and perhaps most importantly,

3. Outreach – increased efforts are being made to educate the public about the problems invasive Mallards are causing for our native waterbirds. The public is a critical part of the solution.

What can I do to help?

• Do not feed or shelter feral Mallards.
• Do not import, buy or sell Mallards or their eggs.
• Do not release Mallards into the wild. Consider having Mallards removed from your property. Contact the State DOFAW at (808) 973-9786 for a permit.
• Be a responsible owner of domestic ducks (e.g., Pekin, Rouen) by keeping ducks, penned, pinioned or clipped so that they do not leave your property.
• Keep your pets like dogs and cats away from wetland areas.
• Support legislation to protect Hawaii’s native birds.
• Help improve the habitat of Koloa maoli and other native waterbirds by removing invasive plants that are taking over wetlands. Go to malamahawaii.org/get_involved/volunteer.php to see volunteer opportunities.

Mālama Hawai‘i, December 2008

Koloa Maoli Lesson Plans

Thank you very much for your interest in teaching your students about the Koloa maoli (native Hawaiian duck). We have developed these lesson plans for students from grades K to 7 as one step toward building awareness, understanding and action about this special bird and the challenges it is facing. The only native duck we have in the main Hawaiian islands, the Koloa maoli is an endangered species that could be gone within our lifetime if more action is not taken to protect and preserve it.

The following matrix indicates the lessons and grade levels for which they are designed. We urge you to look at the lessons at all grade levels and adapt them to meet your needs.


Duckie Diet
Grades: K-1
Big Duck.PDF | Duckie Diet Food Parts.PDF | Duckie Diet Worksheet.PDF | Duckie Diet.PDF

Holoholo Kol0a
Grades: 2-3
Holoholo Koloa Maoli.PDF | Holoholo Worksheet.PDF

Wetlands = Home
Grades: 4-5
Wetlands = Home.PDF

Going Mauka to Makai
Grade: 6
Going Mauka to Makai.PDF

Koloa or Mallard - Which is it?
Grade: 7
Koloa & Mallard Worksheet.PDF | Koloa & Mallard Answer sheet.PDF | Koloa or Mallard.PDF

Click here to view the PDF of Overall Teacher Backgrounds.

There are many people who care deeply about the Koloa maoli and Hawaii’s environment who helped make these lesson plans possible. Mahalo nui loa to: Andrew Cha, Andy Engilis, Jr., Jennifer Higashino, Cal Hirai, Jack Jeffrey, Michelle Gorham Jones, Ella Garcia Kau, Jackie Kozak, Jamie Makasobe, Arlen McCluskey, Mike Nishimoto, Jennie Peterson, Dave Preston, Pauline Sato, Janice Staab, Bill Standley, Caroline Tucker and Kimberly Uyehara.

We also give special thanks to the wonderful teachers who helped us improve the draft lesson plans despite their busy schedules: Cobey Doi, Gayle Enriquez, Adrienne Hale, Roseann Michaud, Mālia Rogers and Sylvia Texeira.

These lesson plans are made by Mālama Hawai‘i through a grant from the Hawai‘i Invasive Species Council and support from The Nature Conservancy, University of California at Davis, Outside Hawai‘i (OC16 television) and Hawai‘i Department of Land and Natural Resources.


Feral Mallards
Hawaii Wetlands
Other Native Hawaiian Water Birds

See VIDEOS on the Maoli Koloa on Malama TV or our Malama Hawai`i YouTube Channel.


Hana Pa‘a, Hana Pono - Fishing Responsibly Brochure This four-page document features the writings of local fishers and scientists regarding the health of Hawaii’s fishery resources, new information on fish life cycles, and ways to improve fishing that also benefit healthy coral reefs. Hana Paa, Hana Pono was created in support of the 2008 International Year of the Reef campaign and first published in Hawai‘i Fishing News.