Finch

The true finches, belonging to the family Fringillidae, are small to medium-sized songbirds. They are equipped with stout, conical beaks well-suited for cracking seeds and nuts, and many species display vibrant plumage. These birds are generally non-migratory residents across a wide variety of habitats. While they have a nearly global native range, they are absent from Australia and the polar regions. This family is large, containing over two hundred species across fifty genera, including canaries, siskins, redpolls, serins, grosbeaks, euphonias, and the Hawaiian honeycreepers, which are morphologically distinct.

Many other birds not in this family are also commonly called finches. These include the estrildid finches of the Old World tropics and Australia, some members of the bunting and New World sparrow families, and the famous Darwin's finches of the Galapagos, which are now classified as tanagers. Historically, finches and canaries were used in coal mines in the UK, US, and Canada to detect carbon monoxide, a practice that ended in the UK in 1986.

The finch family name, Fringillidae, was introduced in 1819 by zoologist William Elford Leach. The taxonomy, especially of the cardueline finches, has been complex and debated, complicated by similar body shapes evolving in species that occupy similar ecological roles. Starting around 1990, DNA studies led to major revisions. For instance, the Neotropical Euphonia and Chlorophonia, once placed with tanagers, are now in their own finch subfamily, Euphoniinae. The Hawaiian honeycreepers, formerly in their own family, are now placed within the Carduelinae subfamily, close to the rosefinches. Large genera like *Carpodacus*, *Carduelis*, and *Serinus* were found to be polyphyletic and were split into separate, monophyletic genera. Today, the family is divided into three subfamilies: Fringillinae (with just the chaffinches), Carduelinae (with 183 species in 49 genera), and Euphoniinae. One bird, Przewalski's "rosefinch," which has ten primary flight feathers instead of the usual nine, is now placed in its own distinct family, Urocynchramidae.

Fossil remains of true finches are scarce, and most can be assigned to living genera. The family likely originated in the Middle Miocene, roughly 20 to 10 million years ago. One unidentifiable finch fossil from the Late Miocene has been found in Hungary.

In terms of size, the smallest true finches include the Andean siskin and the lesser goldfinch, while the largest is probably the collared grosbeak, though the pine grosbeak and evening grosbeak can reach slightly greater lengths or weights. Their beaks are typically strong and stubby, though Hawaiian honeycreepers show an extreme variety of bill shapes due to adaptive radiation. All true finches have nine primary flight feathers and twelve tail feathers. Basic plumage is brownish or greenish, often with black; white is usually limited to wing bars. Bright yellow and red carotenoid pigments are common, while blue colors are rare because yellow pigments turn blue to green. Many species show strong sexual dichromatism, with females lacking the males' bright colors.

Finches are found across the Americas, Eurasia, Africa, and some island groups like Hawaii. They are absent from Australasia, Antarctica, the Southern Pacific, and most Indian Ocean islands, though some European species have been introduced to Australia and New Zealand. They typically inhabit well-wooded areas.