Finch

The true finches are small to medium-sized passerine birds in the family Fringillidae. Finches generally have stout conical bills adapted for eating seeds and nuts and often have colourful plumage. They occupy a great range of habitats where they are usually resident and do not migrate. They have a worldwide native distribution except for Australia and the polar regions. The family Fringillidae contains more than two hundred species divided into fifty genera. It includes the canaries, siskins, redpolls, serins, grosbeaks and euphonias, as well as the morphologically divergent Hawaiian honeycreepers. Many birds in other families are also commonly called "finches". These groups include the estrildid finches (Estrildidae) of the Old World tropics and Australia; some members of the Old World bunting family (Emberizidae) and the New World sparrow family (Passerellidae); and the Darwin's finches of the Galapagos islands, now considered members of the tanager family (Thraupidae). Finches and canaries were used in the UK, US and Canada in the coal mining industry to detect carbon monoxide from the eighteenth to twentieth century. This practice ceased in the UK in 1986. The taxonomy of the finch family, in particular the cardueline finches, has a long and complicated history. The study of the relationship between the taxa has been confounded by the recurrence of similar morphologies due to the convergence of species occupying similar niches. In 1968 the American ornithologist Raymond Andrew Paynter, Jr. wrote: Limits of the genera and relationships among the species are less understood – and subject to more controversy – in the carduelines than in any other species of passerines, with the possible exception of the estrildines [waxbills]. Beginning around 1990 a series of phylogenetic studies based on mitochondrial and nuclear DNA sequences resulted in substantial revisions in the taxonomy. Several groups of birds that had previously been assigned to other families were found to be related to the finches.