The male Hawaiian honeycreepers are more brightly coloured than the females in the Psittirostrini, but in the Hemignathini, they often look very similar. The flowers of the native ʻōhiʻa lehua (Metrosideros polymorpha) are favoured by a number of nectarivorous honeycreepers. Many species of this subfamily have been noted to have a plumage odor that has been termed the Drepanidine odor and suspected to have a role in making the bird distasteful to predators.
The wide range of bills in this group, from thick finch-like bills to slender downcurved bills for probing flowers have arisen through adaptive radiation, where an ancestral finch has evolved to fill a large number of ecological niches. Some 20 species of Hawaiian honeycreeper have become extinct in the recent past, and many more in earlier times, between the arrival of arrival of the Polynesians who introduced the firstrats, chickens, pigs, dogs, and hunted and converted habitat for agriculture.