Overview
Oahu Amakihi: Small honeycreeper with yellow-green upperparts. Yellow throat, breast, and belly, becomes dull towards flanks and vent. Face has black lores. Gray bill is decurved. Legs and feet are gray. One of the least specialized and most adaptable Hawaiian species.
Range and Habitat
Oahu Amakihi: Endemic to Oahu. Found in wet, high elevation forests and drier habitats in the the Wai'anae Range. Frequents both native forest and lower elevation forest consisting of introduced plant species.
Finches (Fringillidae)
ORDER
Also known as perching birds, the order PASSERIFORMES (pronounced pas-ser-i-FOR-meez) is composed of one hundred and eighteen families of birds, among which are included the insectivorous warblers and the seed-eating finches.
FAMILY TAXONOMY
The Fringillidae (pronounced frin-JIHL-lih-dee) is a widespread bird family found on most continents and includes two hundred and seven species of finches in thirty-nine genera.
NORTH AMERICA
Eighty-nine species of finches in twenty-nine genera have occurred in North America and Hawaii. These include familiar feeder visitors such as goldfinches and siskins, the nomadic rosy-finches of the high mountains, and a group with several extinct species; the Hawaiian Honeycreepers.
KNOWN FOR
Finches are known for their seed-eating behavior and cheery songs; characteristics that facilitated and popularized the domestication of the Island Canary. Finches such as White-winged Crossbills are also known for their "irruptive" migrations in search of food sources that can make them locally common one winter and absent the next.
PHYSICAL
Finches are primarily small birds with stout, short bills adapted to cracking open seeds and have short legs for a mostly arboreal lifestyle. Most species also have slightly forked tails and long wings, both useful for the large amount of flying needed to find seeding plants. Although some Hawaiian Honeycreepers share this general structure, others evolved a variety of bill shapes related to the habitat niches they occupy.
COLORATION
North American finches are generally plumaged in shades of red, yellow, brown and dull green - these colors being more vivid in the case of the Hawaiian Honeycreepers. Male finches are more brightly colored than females, the yellow and black plumage of male goldfinches being especially striking.
GEOGRAPHIC HABITAT
Finches in North America occupy forest and non-forest habitats, coniferous forests being favored by most species while native Hawaiian forests are necessary for the survival of the Hawaiian Honeycreepers. The non-forest niche is filled by goldfinches (birds of weedy fields and desert), the House Finch (a desert species that has become adapted to urban environments) and the rosy-finches of alpine snow fields and tundra.
MIGRATION
Most finches are adapted to cold weather and only migrate when seed crops on their breeding grounds become scarce. Rosy-finches practice "vertical migration," moving to nearby lower elevations with better supplies of food during the winter.
HABITS
Members of the finch family are very social birds typically found in flocks outside of the breeding season. Although the rosy-finches take much insect prey on the ground and some Hawaiian Honeycreepers eat nectar, most finches forage for seeds in trees and bushes.
CONSERVATION
While finches in the United States and Canada are doing quite well, most Hawaiian Honeycreeper species are highly endangered with many having already gone extinct and others in decline because of their high susceptibility to introduced diseases such as avian malaria and changes to the native forests they inhabit.
INTERESTING FACTS
The aptly named crossbills have curious curved bills with crossed tips. Although it looks more like a bill deformity than a useful tool, this specialized bill shape is perfect for extracting seeds from pine cones. Males of the House, Cassin's, and Purple Finch species can sometimes develop yellow or orange rather than red plumage depending upon the amount of carotenoids present in their food sources.