Habitat destruction and modification.
The rapid spread of disease-carrying mosquitoes in the lowlands are thought to be responsible for past declines.
The ʻĀkohekohe (Palmeria dolei), or crested honeycreeper, is a species of Hawaiian honeycreeper. It is endemic to the island of Maui in Hawaiʻi. It is the largest honeycreeper on the island at 6.5 to 7 inches (17 to 18 cm) in length. The adults are a glossy black with whitish feathers and stripes going down its side. The underparts are whitish black while the top has orange feathers sticking from wings. The feathers behind the eyes are a reddish color, and have a stream of cream colored feathers coming from the eyes. One of the things that most people recognize about this bird is its whitish gold colored feather crest on its head. The younger birds are brownish black and they do not have the orange feathers of the parents. The legs and bills are a blackish color.
Its natural habitat is wet forests dominated by koa (Acacia koa) and ʻōhiʻa lehua (Metrosideros polymorpha) on the windward side of Haleakalā at elevations of 4,200 to 7,100 feet (1,300 to 2,200 m). During a search for the species in the east Maui forests, there were a record of 415 observations over an area of 11,000 acres (45 km2) and at elevations from 4,200 to 7,100 feet (1,300 to 2,200 m) above sea level. It has been estimated that there are a total of 3,800 ʻĀkohekohe left on Maui in two populations separated by the Koʻolau Gap.
According to the Federal Endangered Species Act, this bird is protected by law along with its habitat. The bird was included in the act in March 1967. It was also a part of many other documents including the Maui-Molokai Forest Bird Recovery Plan in 1967, by the Fish and Wildlife Service. It will serve as a guideline to protect the indigenous life of Maui and Molokaʻi. The final recovery plan in 1984 continues the last, keeping eyes on the species and eradicating any ungulates that are introduced into the area that can harm and or disturb the ʻĀkohekohe and other native forest birds in Maui’s forests.