Akialoa

Hemignathus is a Hawaiian honeycreeper genus in the finch family, Fringillidae. These birds are endemic to the Hawaiian Islands.

Many of its species became extinct during the 19th and 20th centuries due to a combination of habitat destruction, introduced predators, and most importantly mosquito-borne diseases. Some others became extinct in prehistoric times, when Polynesian settlers deforested the lowlands for agriculture.

They have a wide variety of bill shapes and sized; if the genus is broadly defined this diversity is probably the largest of all bird genera living or extinct.

Systematics
The genus Hemignathus is sometimes split into four distinct genera. While it is probably desirable to move at least some species to their own genera, many authorities are reluctant to do so at present due to the lack of comprehensive studies. That half of the taxa are extinct does not make such studies easier.


 * Hoopoe-billed Akialoa, Hemignathus upupirostris or Akialoa upupirostris - prehistoric
 * Giant ʻAkialoa, Hemignathus sp. or Akialoa sp. - prehistoric
 * Lesser Akialoa or Hawaii Akialoa, Hemignathus obscurus - extinct (1940)
 * Oahu Akialoa Hemignathus (ellisianus)ellisianus  or Akialoa ellisiana - extinct (1940)
 * Kauai Akialoa, Hemignathus stejnegeri or Akialoa stejnegeri - extinct (1969)
 * Maui-nui Akialoa or Lanaʻi ʻAkialoa, Hemignathus lanaiensis - extinct (1892)
 * Akiapolaau, Hemignathus munroi
 * Kauai Nukupuu Hemignathus hanapepe - probably extinct (late 1990s?)
 * Oahu Nukupuu Hemignathus lucides - extinct (1837)
 * Maui Nukupuu Hemignathus affinis - probably extinct (late 1990s?)