The akiapolaau is a member of the Hawaiian honeycreeper family (Drepanididae) that has evolved to fill the niche occupied by woodpeckers in many other parts of the world. The akiapōlaau is medium-sized, stocky, short-tailed Hawaiian honeycreeper endemic to Hawaii Island. Its most remarkable feature is the extraordinary bill, which has a long, sickle-shaped upper mandible and a short, straight lower mandible that is only half as long as the upper. Males are larger and heavier than females and have a slightly longer bill. Adult males have a bright yellow head and underparts, a greenish back and wings, and black lores. Adult females differ in color, with a yellowish-white chin, throat, and upper breast that contrasts with a pale yellowish-gray lower breast and belly (USFWS 2006). It creeps along trunks and branches searching for grubs and various arthropods within the bark, and its song is a loud, rapid-fire warble.