Koloa ~ Hawaiian Duck
Anas wyvilliana

Koloa quack like Mallards, but softer and are not as vocal. There are few pure Koloa on Oahu, most are Mallard-Koloa hybrids. You will probably see only hybrids at Ka’elepulu Wetland.
Koloa eat a wide variety of food including snails, earthworms, dragonflies, algae and wetland plants. They are listed as an endangered species.