Akepa

views updated

Akepa

Loxops coccineus coccineus Loxops coccineus ochraceus

Status	Endangered
Listed	October 13, 1970
Family	Drepanididae
Description	Males are bright red-orange with brownish wings and tail, while females are gray to green with considerable yellow.
Habitat	Closed canopy of upland mixed 'ohi'aand koa.
Food	Caterpillars and spiders.
Reproduction	Perhaps a clutch of three eggs.
Threats	Deforestation, predators.
Range	Hawaii

Description

The akepa, Loxops coccineus, is a small finchlike bird with a long notched tail; a body 4-5 in (10.2-12.7 cm) in length weighs about 0.35 oz (10 g). Two akepa subspecies, the Hawaii akepa (Loxops coccineus coccineus ) and the subspecies found on Maui (L. c. ochraceus ), are listed as endangered. Hawaii akepa males are bright red-orange with brownish wings and tail, while females are gray to green with considerable yellow, especially on the breast. Both sexes have yellow bills. The Maui akepa has a gray bill; males are orange or yellow.

Behavior

Akepas, often seen in small flocks, keep mostly to the forest canopy where they forage for insects. Only three akepa nests have ever been discovered, all in natural 'ohi'a (Metrosideros collina ) or koa (Acacia koa ) tree cavities up to 45 ft (14 m) above the ground. These active nests of the Hawaii akepa were discovered in March and May; one had three eggs from which two young were fledged in June. No nests of the Maui akepa have been discovered. The akepa feeds on caterpillars and spiders, occasionally visiting 'ohi'a and other flowers for nectar.

Habitat

The akepa inhabits the closed canopy of upland mixed 'ohi'a and koa forests where it gleans insects from foliage and flowers.

Distribution

The Hawaii subspecies has never been collected outside the island of Hawaii. It was formerly widespread on the island, and in the early 1900s was described as abundant in parts of Kona and Hilo, and on Kohala Mountain. Considered abundant on Maui before 1900, the Maui akepa went into a sharp decline in the twentieth century. Only six sightings were reported between 1900 and 1980, all within 2 mi (3.2 km) of Pohaku Palaha at the upper junction of Kipahulyu Valley and Haleakala Crater.

At the end of the twentieth century, its distribution included the upper slopes of Mauna Kea and Mauna Loa on the windward coast, the southeastern slopes of Mauna Eoa, and the southwestern slopes of Hualalai. It was found in five to 10 areas surveyed on Keauhou Ranch and Kilauea Forest Reserve in densities of 32-106 per sq mi (12-41 per sq km). It is very rare in the mamane (Sophora chrysophylla ) forests of Mauna Kea, where it probably occurs only as a straggler. It was found at 3,000 ft (910 m) in Hawaii Volcanoes National Park in the 1940s, but there are no late twentieth century records for the park. The population in the Ka'u Forest Reserve and adjacent areas was estimated to be 5,300 in 1976. Total akepa species, including the subspecies on Oahu, was estimated in 1980 at about 15,800 birds. Only eight Maui akepa were recorded on Maui during a 1980 study; from this was extrapolated an islandwide population estimate of 230.

Threats

Avian diseases have been responsible for the historic decline of many native Hawaiian birds, including the akepa. Avian pox and avian malaria came to the islands in the 1820s with introduced mosquitoes. Forest bird populations above 4,900 ft (1,500 m), where mosquitoes are less abundant, have a lower incidence of disease. Other introduced insects, such as parasitic wasps and predaceous ants, have eliminated many native insects that once served as food for native birds. The most immediate threat to the akepa is the continued degradation of its remaining habitat. Upper elevation koa forests on Hawaii have been drastically reduced through logging and subsequent conversion to pasture. Animal grazing and browsing have severely modified the forests that remain. The wetter forests are subject to rooting by feral pigs, which spread the seeds of exotic plants such as banana poka (Passiflora mollissima ) and strawberry guava (Psidium cattleianum ) in their feces after ingesting the fruits.

Widespread dieback of 'ohi'a, Hawaii's most common native forest tree, has modified large portions of habitat on the island of Hawaii, and additional areas may be threatened. The causes for the death of this tree are not known. Dieback continues between the elevations of 2,500 and 6,000 ft (760 and 1,830 m), primarily in the Hilo, Kau, Olaa, and Waikea areas. An additional threat to the akepa is predation. Several potential bird predators have been introduced to Hawaii, including the domestic cat, the Polynesian rat, the black or roof rat, the Norwegian rat, the mongoose, and the common mynah.

Conservation and Recovery

Recover of the akepa and similar birds largely depends on habitat conservation and restoration. In late 1985, the U. S. Fish and Wildlife Service (FWS), the Nature Conservancy of Hawaii, and the state purchased a total of 8,300 acres (3,360 hectares) of native forest on the island of Hawaii. This marked the first phase of the proposed establishment of a 33,500-acre (13,560-hectare) preserve, the Hakalau Forest National Wildlife Refuge, located on the northwestern slope of Mauna Kea. The refuge is designed primarily to preserve the habitat of endangered forest birds and contains some of the best preserved koa-'ohi'a forests remaining on the islands. Another 400-acre (162-hectare) parcel was acquired in 1988 by the Nature Conservancy and sold to the FWS for inclusion in the refuge. Since the akepas, as well as other forest birds, are in danger of extinction while recovery efforts are studied and implemented, the FWS is exploring the possibility of captive propagation. The ultimate goal of such a program would be the creation of a captive flock that would serve to furnish birds to supplement wild populations. Little is known, however, about the ability of Hawaiian forest birds to live and breed in captivity. To test the feasibility of captive propagation, the FWS began a trial program in cooperation with several U. S. zoos. In late 1988, 15 pairs of a nonthreatened honeycreeper, the common amakihi (Hemignathus virens ), were sent to participating zoos to determine if the birds can live and breed in captivity. If successful, this effort will provide essential information on managing a captive propagation program for the rarer Hawaiian forest birds.

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/

U. S. Fish and Wildlife Service
Pacific Remote Islands Ecological Services Field Office
P. O. Box 50088
Honolulu, Hawaii 96850-5000
Telephone: (808) 541-1201
Fax: (808) 541-1216