Primitive koa finch


The primitive koa finch is a species of Hawaiian honeycreeper. It was endemic to Hawaii. Of the four species in the genus Rhodacanthis, it and the scissor-billed koa finch became extinct before the arrival of the first Europeans to Hawaii in 1778. It is known as the ancestor of all koa finches.

Description

An adult primitive koa finch was slender and had a total length of about. There was probably a small distinct difference between the sexes. Based on fossils, it is known that the adult primitive koa finch had a slightly curved, thick bill.

Distribution

Primitive koa finch fossils have been found on Maui and Oahu. It is believed that it inhabited lowland dry forests and savannas, where dominant plant species included ka palupalu o kanaloa, aalii, loulu, and koaia. Unlike other species of Rhodacanthis, koa was not present in significant numbers in its habitat.

Diet

The primitive koa finch was a granivore, with a bill adapted to eat the hard seeds and pods of legumes, especially ka palupalu o kanaloa and koaia. It may have also taken caterpillars and aalii berries, as these were observed being eaten by other species in the genus.

Status

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.