Finch

I

Introduction

Finch, common name given to several unrelated groups of seed-eating birds including the true finches, the Hawaiian honeycreeper, and a family of tiny birds of tropical and subtropical areas of Eurasia. Many tropical American birds also have the common name “finch”; examples include the yellow finches, brush finches, warbling finches, and several genera of Darwin's finches, native to the Galápagos Islands.

II

True Finches

The true finches exhibit their greatest diversity in Eurasia, where the chaffinch is one of the most familiar species. Several genera are represented in both the Americas and Eurasia, notably the goldfinches and siskins. The house finch, the purple finch, and Cassin's finch are native to North America; the rosefinches are found throughout Asia.

Many members of this group are fine songsters and are popular as cage birds, especially the canary and its relatives. Among the largest species is the hawfinch of Europe, which can crack cherry stones with its heavy bill and powerful jaw muscles. Although not bearing the name “finch”, the crossbill belongs to the true finch group.

III

Estrildid Finches

Esteemed as cage birds, these tiny birds are native to Africa, Asia, and Australia, but have been widely introduced elsewhere; nine species, for example, have become established on the Hawaiian Islands. Most common in captivity is the zebra finch, an Australian species widely kept in laboratories for behavioural and other studies because it readily breeds in cages. Many members of this group have names other than finch; examples include the avadavats, mannikins, silverbills, and waxbills.

IV

Darwin's Finches

At some time in the past, a finch of some sort reached the Galápagos Islands in the Pacific Ocean off the west coast of South America. Its descendants radiated into separate ecological niches on the various islands, ultimately evolving into 14 species. One species evolved outside the Galápagos archipelago, having reached Coco Island, almost 800 km (500 mi) to the north-east. All are blackish or dull brownish grey, with or without streaks. They differ primarily in size and notably in the size and shape of their bills. These vary from a warbler-like, insect-eating bill to others with heavy, grosbeak-like bills for cracking hard seeds and nuts. One species is a tool user, using a cactus thorn to dislodge grubs from holes in trees.

Scientific classification: True finches constitute the subfamilies Fringillinae and Carduelinae of the family Fringillidae. Hawaiian honeycreepers make up the subfamily Drepanidinae. The chaffinch is classified as Fringilla coelebs. The goldfinches and siskins are classified in the genus Carduelis. The house finch is classified as Carpodacus mexicanus, the purple finch as Carpodacus purpureus, and Cassin's finch as Carpodacus casinii. The rosefinches are also classified in the genus Carpodacus. The canary and its relatives are classified in the genus Serinus. The hawfinch is classified as Coccothraustes coccothraustes. The crossbills are classified in the genus Loxia. Estrildid finches make up the family Estrildidae. The zebra finch is classified as Poephila guttata. Yellow finches belong to the genus Sicalis, brush finches to the genus Atlapetes, and warbling finches to the genus Poospiza, all of the family Emberizidae.