Greater koa finch and maximum growth of a single species of koa finch. The greater koa finch was a granivore, preferring the pods and seeds of koa ("Acacia koa"). It was also observed eating caterpillars and aalii ("Dodonaea viscosa") seeds. The last confirmed sighting was in 1896, although there were sporadic later reports. Like its close relative the lesser koa finch, this bird lived in small stretches of mesic forest on the Big Island of Hawaii. These forests were dominated by its preferred food source, koa ("Acacia koa"), and were logged and replaced with pasture beginning in 1850. Grazing by cattle inhibited the
Acacia koa survives best in pasture when planted under koa. This is because koa trees reduce radiative cooling, preventing frost damage to ōhia lehua seedlings. Koa is the preferred host plant for the caterpillars of the green Hawaiian blue ("Udara blackburni"), which eat the flowers and fruits. Adults drink nectar from the flowers. Koa sap is eaten by the adult Kamehameha butterfly ("Vanessa tameamea"). The koa bug ("Coleotichus blackburniae") uses its rostrum to suck the contents out of koa seeds. Koa is vulnerable to infection by koa wilt. Acacia koa Acacia koa is a species of flowering tree in the pea family,