The 'Äkohekohe is a brightly colored Hawaiian honeycreeper with a unique appearance and boisterous, aggressive behavior. Approximately 18 cm long, it has black plumage highlighted with brilliant orange-scarlet and silver lanceolate feathers. On adults, a prominent bushy white feather crest curves forward over the bill, forming within the first year (prior to any breeding activity) and explaining the English name for this species, Crested Honeycreeper. Its Hawaiian name, 'Äkohekohe (pronounced "ah ko-hay ko-hay"), is derived from one of the calls it commonly gives from the treetops of the rain forest. This species has a large repertoire of raspy, guttural calls, making it an easy bird to locate. Primarily nectarivorous, it is usually seen perched or hopping across the canopy of 'öhi'a (Metrosideros polymorpha) trees searching for its primary food, the nectar of 'öhi'a blossoms. 'Äkohekohe are strong fliers and are often seen aggressively chasing other species from their preferred feeding sources and nesting sites.
The 'Äkohekohe inhabits perpetually misty, high-elevation rain forest on the island of Maui in the Hawaiian Archipelago. It was formerly found on the island of Moloka'i, but this population is now extinct ( Richardson 1949 , Scott et al. 1986 ). The 'Äkohekohe was infrequently reported during the early 1900s-not at all during the 1920s and 1930s-and it was considered rare when rediscovered in a remote area in eastern Maui during the late 1940s and early 1950s. The apparent scarcity of this bird probably reflected the fact that few ornithologists ever traveled to the remote interior of this rain forest.
Research on the 'Äkohekohe began in the 1970s with extensive surveys that mapped its distribution and estimated the species' population size at 3,800 individuals ( Scott and Sincock 1977 , Scott et al. 1986 ). Studies on interspecific competition of forest birds identified the 'Äkohekohe as an aggressive competitor in the nectarivore community of Maui rain forests ( Mountainspring and Scott 1985 , Carothers Carothers 1986a , Carothers 1986b ). Breeding biology was investigated by Ellen VanGelder ( Vangelder 1996 ), who located the first nests for this species. A 3-year field study from 1994-1997 of the species' population ecology, including breeding biology, foraging behavior, and territoriality, was carried out by the Pacific Island Ecosystems Research Center Biological Resources Division of the U.S. Geological Survey (PIERC/BRD). The Peregrine Fund plans to incorporate these studies in managing their first captive propagation program for the 'Äkohekohe.
The greatest threats to the 'Äkohekohe are a result of human activity, primarily deforestation and introductions of exotic species. These changes created unsuitable environments, led to degradation of remaining native forests by feral ungulates, and introduced avian blood-borne diseases and predation risks previously unknown to Hawaiian forest birds. The 'Äkohekohe has been reduced to a single population and eliminated from elevations below 1,500 m, and it has little chance to expand its present distribution. Interests to conserve this endangered species focus on habitat preservation through the construction of fence enclosures and removal of feral ungulates. Continued preservation of habitats, in conjunction with programs for captive propagation and removal of destructive exotic species, will provide the greatest opportunities to maintain and increase populations of the 'Äkohekohe.