Laysan Duck

The Laysan duck, also known as the Laysan teal, is a small, dark brown dabbling duck endemic to the Hawaiian Islands. It is distinguished by a prominent white eye-ring, and both sexes exhibit an iridescent purplish-green patch on the wing. Males may have faint iridescence on the head or neck and slightly upturned central tail feathers. The bill is short and spatulate, with males typically having dark green bills with black blotching, while females have dull orange bills with similar blotching. Notably, these ducks often have a ring of fat around their necks, and older birds may display leucistic feathering on the head and neck. Their legs and feet are orange, with males generally brighter than females.

Identification Tips

When identifying the Laysan duck, look for the characteristic white eye-ring and the dark brown plumage. The male's bill is dark green with black blotches, and the female's is dull orange with black blotches. The iridescent wing patch is visible in both sexes. The duck's reduced wings and wing muscles are indicative of its poor flying ability, and it may exhibit a freeze response when threatened.

Habitat

The Laysan duck inhabits the terrestrial and wetland areas of Laysan Island and two atolls within the Hawaiian archipelago. It has adapted to a ground-based foraging lifestyle due to the historical absence of ground predators in its environment.

Distribution

Once widespread across the Hawaiian Islands, the Laysan duck's range has contracted significantly. Today, it is found only on Laysan Island and two atolls, having been driven to near-extinction on other islands by introduced predators and habitat destruction.

Behaviour

The Laysan duck is a terrestrial forager, adept at walking and running. It engages in energetic fly-snapping sprints through swarms of brine flies and dabbles along lake shallows for food. During the day, especially in the breeding season, it hides among grass and shrub vegetation to avoid avian predators. It is more active from dusk to dawn, feeding on the lake's surface.

Breeding

Breeding pairs form in autumn, with nest building commencing in spring. Females construct well-concealed ground nests lined with grass and down feathers. Clutch sizes average around four eggs on Laysan Island, with larger clutches observed on Midway Atoll due to better food availability. Ducklings are precocious, feeding independently by their second day, though they remain under the hen's care for up to 60 days.

Diet and Feeding

Laysan ducks forage for macroinvertebrates, algae, leaves, and seeds. They exhibit a unique fly-snapping behavior to catch brine flies and also engage in dabbling and filter feeding in various environments.

Conservation status

The Laysan duck is classified as Critically Endangered. Its population plummeted due to introduced predators and habitat destruction but has shown signs of recovery following conservation efforts, including translocations to predator-free atolls and the establishment of a second population on Midway Atoll. Despite these successes, the species remains vulnerable to threats such as habitat loss, human disturbance, and climate change.