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
Greater koa finch regeneration of koa forests, while introduced black rats ("Rattus rattus") preyed on young birds. Avian pox ("Poxvirus avium") and malaria ("Plasmodium relictum"), spread by mosquitoes, may have also been a factor. However, even before these issues became important, the koa finches were probably already living in marginal habitat due to the loss of lowland koa forests, as evidenced by the extinction of the other koa finch species (which lived on lower-elevation islands) prior to European contact. Greater koa finch The greater koa finch ("Rhodacanthis palmeri") was a species of finch in the Fringillidae family. It was found only in the