The cardueline finches are a subfamily, Carduelinae, one of three subfamilies of the finch family Fringillidae, the others being the Fringillinae and the Euphoniinae. The Hawaiian honeycreepers are now included in this subfamily.[1] Except for the Hawaiian honeycreepers which underwent adaptive radiation in Hawaii and have evolved a broad range of diets, cardueline finches are specialised seed eaters, and unlike most passerine birds, they feed their young mostly on seeds, which are regurgitated.[2] Besides this, they differ from the other finches in some minor details of their skull.[2] They are adept at opening seeds and clinging to stems, unlike other granivorous birds, such as sparrows and buntings, which feed mostly on fallen seeds.[3] Some members of this subfamily are further specialised to feed on a particular type of seed, such as cones in the case of crossbills.[2] Carduelines forage in flocks throughout the year, rather than keeping territories, and males defend their females rather than a territory or nest.[4]
The name Carduelina[e] for the subfamily was introduced by the Irish zoologist Nicholas Aylward Vigors in 1825.[5][6] Carduelinae is derived from the Latin name carduelis and the binomial name Carduelis carduelis for a goldfinch, one of the species in the subfamily.[7]
The Carduelinae subfamily contains 186 species divided into 49 genera. Of the 186 species, 15 are now extinct; these are the Bonin grosbeak and 14 Hawaiian honeycreepers.[8]