Lesser koa finch birds, when the first and last specimens were shot. In all, there were eight specimens that were collected, all of them from in trees that were used by the greater koa finch. There were several other related species living at its time including one from Oahu, one from Maui and one living in Kona. It has been confused with a house finch and many novice bird watchers claim false sightings. It was also confused with the O’u, which was still common on Hawaii and Kauai until the latter's recent disappearance. Lesser koa finch The lesser koa finch ("Rhodacanthis flaviceps") is
Acacia koa confirmed this close relationship; the estimated time of divergence is about 1.4 million years ago. "A. heterophylla" sequences nest within those of the more diverse "A. koa", making the latter paraphyletic. Both species are thought to be descended from an ancestral species in Australia, presumably their sister species, "Acacia melanoxylon". Dispersals most likely occurred via seed-carrying by birds such as petrels. Both species have very similar ecological niches, which differ from that of "A. melanoxylon". A closely related species, koaia or koaie ("A. koaia"), is found in dry areas. It is most easily distinguished by having smaller seeds that are