Anas laysanensis
Laysan duck

The Laysan Duck originally resided along all of the Hawaiian archipelago but within the past two hundred years has found its range greatly diminished. At the current time the Laysan Duck can only be found on the small, 900-acre, island (Laysan Island) that is under the protection of the US Fish and Wildlife Service.

Grouped among the Dabbling ducks such as the Mallard, the Laysan Duck prefers land habitats to aquatic and aerial habitats. The Laysan Duck is normally observed along the coast of Laysan Island or around the inland lake found on the island. This is where they reside year round. Studies of DNA in duck bones throughout the Hawaiian Islands have shown that the Laysan Duck's range once included the entire Hawaiian Archipelago before the mass extinctions that occurred in that region after Polynesian colonization between 400 and 600 AD.

Average weights for this long-lived duck vary with its age. An individual at age 14 can weigh 98.1 grams while an individual at age 45 can weigh 402.0 grams. There is little difference between the plumages of males and females. Both are dull, dark brown with distinctive white eye rings and white feathering on head and neck. The main difference lies with bill coloring: the male bill is yellowish green with black spotting, while the female bill is dull orange. The Laysan Duck has strong wings that allow it quick take offs but not prolonged flight. The Laysan Duck spends most of its time on its legs dabbling into the water and on land for food.

The Laysan Duck is rarely observed swimming or flying and spends about 10 percent of its time each day walking or running on the ground. During midday the ducks rest and they come out to feed on the island's highlands during the evening and night. Vocalizations are similar to that of a mallard but are rarely heard except during courtship. Male ducks fighting for mates are observed pulling at each other's breast feathers.

The main food staple for this species is macroinvertebrates. The Laysan Duck is not a diver or swimmer and merely dips its head into the water to feed on aquatic plants, seeds and snails. They also do some filter feeding for moth larvae and pupae. A peculiar method of feeding that has been observed in this species is its tendency to run through swarms of adult brine flies with its neck extend and mouth open in order to trap the flies in its mouth. The climate in the Pacific Ocean undergoes little seasonal variation and therefore migration by this duck to follow food is unnecessary, as supplies stay constant year round.

Their refuge is an area of high economic value to developers.

The population bottomed at 150 recently in 1993 following a drought in the region. Their present numbers are up to 600, which is considered a success on the part of the US Fish and Wildlife Service. Currently the Laysan Island is now a refuge for these birds, but has been maintained loosely as a Bird Sanctuary since 1909.