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.
Koa wilt to the Hawaiian islands. It ranges in size from 15 to greater than 50 feet with a canopy spread of 20 to 40 feet. It has a showy white flower and blooms sporadically. Mature leaves are sickle shaped. Koa wilt is typically a fatal pathogen for its host. In only a few months, a tree may lose its entire canopy and die. Trees less than fifteen years old are typically the most susceptible. Symptoms include stains in cambium, roots, and sapwood as well as chlorosis (yellowing), canopy dieback, brown and wilted leaves, oozing sap, and bark cankers. The Koa wilt