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 reaching in five years on a good site. Initially, bipinnately compound leaves with 12–24 pairs of leaflets grow on the koa plant, much like other members of the pea family. At about 6–9 months of age, however, thick sickle-shaped "leaves" that are not compound begin to grow. These are phyllodes, blades that develop as an expansion of the leaf petiole. The vertically flattened orientation of the phyllodes allows sunlight to pass to lower levels of the tree. True leaves are entirely replaced by long, wide phyllodes on an adult tree. Flowers of the koa tree are pale-yellow spherical racemes with