Primitive koa finch viscosa") berries, as these were observed being eaten by other species in the genus. The primitive koa finch is believed to have gone extinct some time after Polynesians first arrived in Hawaii, however very little else is known about this species. Due to its early extinction it is only known from fossil remains. Other Hawaiian honeycreepers are known to have become extinct or very rare due to habitat loss, introduced predators and avian diseases. It is possible the extinction of the primitive koa finch also involved these factors. BirdLife International 2004. Himatione sanguinea. 2006 IUCN Red List of Threatened Species.
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