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.
Lesser koa finch cattle and created ranches in the koa forests, the younger koa trees began to be trampled by the cows. The cows also stripped the leaves off the trees at a faster rate than the leaves normally fell. The older trees were too tall to be defoliated, but their roots were kicked and pulled out, causing them to grow weak and eventually die. With the loss of the native koa trees the last birds began to die off. Finally, the bird was never seen after the year 1891. It is also noted that there were only two confirmed sighting of the