Birds of Hulē‘iaHawaiian Moorhen / Gallinula chloropus sanvicensis / ‘Alae ‘ula
Population No historical population estimates are available for the endemic ‘alae ‘ula. Because they are such secretive birds, it is difficult to conduct surveys of this species. It is believed that they were common on the main Hawaiian islands in the 1800s but radically declined by the mid 1900s. Surveys in the 1950s and 1960s estimated no more than 57 individuals. However, the spread of aquaculture in the 1970s and 1980s helped boost their numbers by providing more suitable habitat for these birds, Today, ‘alae ‘ula can be found only on O‘ahu, Kaua‘i, and possibly on Maui and Moloka‘i. The Kaua‘i population is found in lowland wetlands and valleys such as Hulē‘ia. A sizable population is found at Hanalei National Wildlife Refuge. The primary cause of decline to this Hawaiian native waterbirds has been loss of wetland habitat. Other factors include introduced predators, alien plants, introduced fish, disease, hybridization, and environmental contaminants. Habitat These secretive birds can be found in freshwater marshes, taro patches, irrigation ditches, reservoirs, and wet pastures. They favor dense emergent vegetation near open water, floating or barely emergent mats of vegetation, and water depths of less than 3 feet (1 meter). Feeding Habits The ‘alae ‘ula eats mollusks, insects, water plants, and grasses. Breeding ‘Alae ‘ula nest year-round but the active season is usually from March through August. It is believed that the timing of nesting is related to water levels and vegetation growth. The ‘alae ‘ula usually lays an average of 5 to 6 eggs and incubation is about 22 days. They are good swimmers and chicks can swim shortly after hatching. |