 Its various calls include an upslurred whistle, a short "cheedle-ee" warble, and a short "sweet".Due to the recent disappearance of the Maui and Kauai nukupu'us in the 1990s, leading to fears that they may be extinct, the akiapōlāau may be the last of its genus.It is the only member of the subgenus Heterorhynchus, which has a woodpecker-like feeding habitat and exclusively preys on insects, in contrast to the nukupu'us, which were both insect-eaters and also hummingbird-like nectarivores"."