Greater koa finch below. It had a thick black bill which allowed it to break open seed pods that were found in the trees. In historical times, its range was largely confined to the Kona District of the island of Hawaii, although it was observed in the Kīlauea area in 1895. It was much more widespread prior to the arrival of humans in Hawaii, and related species lived on other islands. In Kona, it co-occurred with the closely related lesser koa finch ("Rhodocanthis flaviceps"), and the Kona grosbeak. The lesser and greater koa finches were once thought by scientists to be the minimum
Acacia koaia It can be seen on ranch land in North Kohala, and at a small fenced exclosure outside of Waimea known as the "koaia" sanctuary. "Koaia" is one of the species being used to revegetate the island of Kahoolawe, which lost most of its plant life to overgrazing and ordnance testing. Native Hawaiians ground "koaia" leaves and bark with "auaukoi" ("Senna occidentalis") and "kikānia pipili" ("Desmodium sandwicense") stalks. The mixture was then hydrated and used in a steam bath to treat diseased skin. The wood of "koaia" is harder and more dense than that of "koa". It was used to make