Kaua'i Nukupu'u

Hemignathus lucidus hanapepe

Description

The rare Kauai nukupu'u, Hemignathus lucidus hanapepe, is a honeycreeper about 5.5 in (13.7 cm) in length that has a downcurved, sickle-shaped bill up to 1.2 in (3 cm) long. The upper mandible is twice the length of the lower. The male is olive above with a yellow head and underparts; the female is gray-green above. Both sexes have a black lore patch (the area between the bill and the eye).

Discovered on Kauai by S. B. Wilson in 1887, the Kauai nukupu'u is one of three subspecies of Hemignathus lucidus. The Maui subspecies, H. l. affinis, survives in small numbers; the race formerly on Oahu, H. l. lucidus, is extinct.

Behavior

The nukupu'u gleans caterpillars, insects, and larvae from tree trunks and branches, hammering on the surface of a tree to produce a reverberant, staccato sound. Their preferred food appears to be small brassy weevils of the genus Oodemas. The nukupu'u probably moves in search of food resources, but it is non-migratory. Sometimes individuals come to the ground to pick up gizzard stones.

The nukupu'u's song is a short, loud trill. The call note is a loud "kee-it," very clear and distinct when the birds are in solitary pairs. This vocalization is also used for individuals to keep track of one another when apart.

Habitat

The nukupu'u occurs in the wet to mesic ohia forests on the upper plateau of the Alaka'i swamp of Kauai, characterized by swamp wetland, streams, bogs, and steep terrain.

Distribution

The nukupu'u, found on both Kauai and Hawaii, has always been extremely rare. It was considered scarce in the late nineteenth century, and only four sightings were made in the twentieth century.

The nukupu'u is known to nest in koa trees in the Kokee area and along both sides of the Waimea Canyon on Kauai. It was reported in the 1980s from Kohala Mountain on the island of Hawaii, where the bird had not been seen since the 1800s. Nukupu'u's close relative, H. l. affinis, inhabits the upper northeast slope of Haleakala on Maui. It was not found on Kauai during survey count periods from 1968 to 1973, nor again in a 1981 census. If the Kauai nukupu'u survives, it is in the pristine seclusion of the Alakai Swamp Wilderness Sanctuary; a remote possibility exists that it also survives in north Alakai Swamp or in the unexplored areas of La'au Ridge and Namalokama Mountain.

Threats

Most of the natural lowland habitat of the Kaua'i nukupu'u has been destroyed through conversion to agricultural and other land-uses. Its surviving habitat has been degraded by invasive alien plants, non-native mammalian herbivores, and fires set by humans. The bird and its nests have been predated by introduced mammals (such as mongooses and cats), and mosquito-borne diseases have taken a heavy toll. The Kaua'i nukupu'u only survives in perilously small numbers in higher elevation forests where human influences are less and disease-carrying mosquitoes do not occur. Even there, however, the Kaua'i nukupu'u is threatened by introduced plants, non-native birds that compete for habitat, and mammalian predators.

Conservation and Recovery

So little is known about the location of nukupu'u populations that the only conservation efforts are the general plans to protect all Kauai birds. However, if the Alakai Swamp Wilderness Sanctuary is the home of the surviving individuals, then there is hope that the species may be able to repopulate because of the low numbers of predators and competitors.

Contact

U.S. Fish and Wildlife Service
Office of the Regional Director
Eastside Federal Complex
911 N.E. 11th Avenue
Portland, Oregon 97232-4181
Telephone: (503) 231-6118
Fax: (503) 231-2122
http://pacific.fws.gov/

Reference

U.S. Fish and Wildlife Service. 2000. Nuku pu'u (Hemignathus lucidus ). http://www.r1.fws.gov/pacific/wesa/nukupuu.html