Maui Parrotbill

Pseudonestor xanthophrys

Description

The Maui parrotbill (Pseudonestor xanthophrys ) is a chunky, short-tailed bird, about 5.5 in (14 cm) long. It is olive-green above, yellow below, and has a prominent yellow eye stripe. A heavy, hooked, parrotlike bill gives this honeycreeper a top-heavy appearance.

Behavior

The Maui parrotbill finds and feeds on insect larvae and pupae by using its powerful bill to tear into dead wood. The parrotbill's breeding biology is unknown.

Habitat

The species is presently found only in 'ohi'a (Metrosideros colina ) forests on Maui at elevations of 4,300-6,800 ft (1,310.6-2,072.6 m). Formerly, it was also common in koa (Acacia koa ) and dry lowland forests.

Distribution

The parrotbill is known from fossil deposits on the north coast of Molokai in the Hawaiian Islands, representing a pre-Polynesian population that inhabited dry lowland forests. On Maui, the parrot-bill inhabits the northeastern slope of Haleakala, the 10,000-ft (3,048-m) volcano that dominates the eastern end of the island. The center of its present range is between Puu Alaea, Kuhiwa Valley, Lake Waianapanapa, and upper Kipahulu Valley, with a narrow extension west to near the Haleakala Ranch. Although its range extends over 8 mi (12.9 km), the population is concentrated in an area of less than 5,000 acres (2,023.4 hectares). A 1980 population estimate of 500 is not believed to have changed significantly.

Threats

Large tracts of forest, especially on the dry, leeward slopes, were cleared for agriculture by the Polynesians, and fire was commonly used to clear forests to maintain the pili grass used for housing thatch. European settlers eliminated all dry forest on Maui up to at least 5,000 ft (1,524 m) for ranch pastures. By the turn of the century almost all forest except the very wet 'ohi'a forest on upper mountain slopes had been eliminated, and with it many Hawaiian birds.

Grazing animals were introduced on Maui over a hundred years ago and many became feral. Their rooting and trampling were recognized as problems as early as the 1930s, and a program was established to eradicate them. Hunting now controls the feral pig and goat populations. Introduced plants, insects, and diseases have spread aggressively. Predation by introduced rats is undoubtedly a factor in the decline of endangered Hawaiian forest birds, since rats are able to climb trees in search of eggs and young birds. Avian diseases, especially pox and malaria, were spread by introduced mosquitoes and have played a large role in the decline of many native Hawaiian birds. Most remaining birds live at higher elevations, where the mosquito density is low. Scientists are now concerned that a temperate-zone subspecies of the night mosquito (Culex pipiens pipiens ) may become established at the higher elevations and further spread avian disease. The first effort to conserve native birds was made in 1903, with the creation of the State Forest Reserve system. Designed primarily to protect the watershed, this system nonetheless instituted practices beneficial to wildlife such as fencing, hunting feral animals, and reforesting. The system holds and actively manages about 30% of the state's forests, including land on Maui.

Conservation and Recovery

The Nature Conservancy manages the Waikamoi Kamakou Preserves, and Haleakala National Park has undertaken a program to control some exotic plants. A portion of the Haleakala Crater district has been fenced. The U.S. Fish and Wildlife Service is currently exploring a captive propagation program for Hawaiian forest birds to furnish birds to supplement remaining wild populations.

Contacts

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N.E. 11th Ave.
Portland, Oregon 97232-4181
Telephone: (503) 231-6121
http://pacific.fws.gov/

Pacific Remote Islands Ecological Services Field Office
300 Ala Moana Blvd., Room 3-122
P.O. Box 50088
Honolulu, Hawaii 96850
Telephone: (808) 541-1201
Fax: (808) 541-1216

Reference

U.S. Fish and Wildlife Service. 1984. "The Maui-Molokai Forest Birds Recovery Plan." U.S. Fish and Wildlife Service, Portland, Oregon.