Fringillidae Finches, Euphonias, and Allies
Version: 1.0 — Published March 4, 2020
Introduction
Fringillids vary widely, from the streaky brown of the European Twite to the brilliant colors of Neotropical euphonias, and from the sharp, simple bills of siskins to the massive seedcrackers of hawfinches and the chisels and decurved probes of Hawaiian honeycreepers. Yet this diversity masks some interesting shared traits. They are almost universally fond of fruits and seeds, so much so that even the nestlings are reared on them. Their mobility helps explain why they are the most widely distributed of all the nine-primaried oscines—and also why it is no big surprise that the spectacular diversification of Hawaii’s honeycreepers was seeded by a fringillid ancestor that colonized this isolated archipelago many millions of years ago.
Habitat
Fringillids live in diverse habitats, from arid lowland scrub and savanna to dense tropical rainforests and high alpine talus slopes.
Diet and Foraging
Most finches feed primarily on seeds, fruit, and other vegetable matter. Many, particularly those of cold Northern Hemisphere habitats, are nomadic, traveling large distances in search of good seed crops. Many Northern Hemisphere species are also quite specialized for different types of seeds. The Loxia crossbills are near the extreme end of this specialization, with uniquely crossed mandibles suitable for prying open conifer cones to extract the seeds. The Hawaiian honeycreepers, widely known for their diversity of bill shapes and sizes leading to strong feeding specialization, contain species specializing on nectar, seeds, nuts, or insects. Fringilla species feed their young insects, but the others feed their young seeds or fruit.
Breeding
Fringillids are monogamous with biparental care. Some nomadic species, such as Loxia crossbills, have been recorded nesting in all months of the year, and are limited only by the availability of conifer seeds for food. Others, such as the American Goldfinch Spinus tristis, nest relatively late in the summer, once their preferred nestling food, thistle seed, has ripened. Most fringillids build open cup-shaped nests of grass, twigs, rootlets, and other materials, most often placed in a tree or shrub, though alpine species place their nests in a crack in the rocks or under a cliff ledge, and euphonias build a dome nest with a side entrance. Nests of some species are often lined with feathers or plant down. Females typically lay 2 to 7 eggs, and euphonias lay large clutches for a tropical frugivore (2 to 5 eggs). Females generally build the nest and seem always, alone, to incubate. Across the breadth of environments these birds occupy, incubation can take as little as 9 days or as much as 19, but the eggs of most species hatch after 12 to 14 days. Nestlings fledge after about 10 to 27 days, and the young are cared for post-fledge for up to two weeks or so in the temperate zone and for more than a year in some Hawaiian species. In most species, both male and female feed the chicks.
Conservation Status
The 36 fringillid species at risk (18%) are threatened primarily by habitat destruction and introduced predators (7 NT, 10 VU, 9 EN, 7 CR, 3 CR(PE)). The endangered Red Siskin Spinus cucullata, once widespread in the foothills of northern Venezuela and Guyana, has been all but annihilated in the wild by trapping for the cage-bird trade. Two endangered fringillids in Somalia (Warsangli Linnet Acanthis johannis) and Ethiopia (Yellow-throated Seedeater Serinus flavigula) were never known to be widespread, and both are limited to a few patches of hill desert scrub, threatened by fire and the encroachment of agriculture. The critically endangered Sao Tome Grosbeak Neospiza concolor and endangered Hispaniolan Crossbill Loxia megaplaga and Azores Bullfinch Pyrrhula murina are threatened by introduced predators and by habitat destruction and conversion. All of these problems with endemic island populations are eclipsed by the demise of the Hawaiian honeycreeper radiation. Many species in this distinctive clade have already gone extinct, and of the 20 species that may still remain only two have a conservation status of least concern. Three are critically endangered and possibly extinct and six are critically endangered, all due to multiple insults: the clearance of native forest, the introduction of predatory and habitat-destroying mammals, and the introduction in the 19 century of mosquitoes carrying avian malaria, to which the native birds had no resistance.
Systematics History
Fringillidae is part of the large radiation of oscine passerines known as the superfamily Passeroidea. Though one well-sampled molecular study suggested that Fringillidae is sister to Passeridae (Ericson & Johansson 2003), the vast majority of studies have indicated that Fringillidae is sister to the large New World nine-primaried oscine radiation (Yuri & Mindell 2002, Johansson et al. 2008b, Treplin et al. 2008, Fjeldså et al. 2010, Zuccon et al. 2012, Barker et al. 2013). Within Fringillidae, there are three distinct subfamilies: Fringillinae, consisting of only two species, is sister to the remaining members of the family (Lerner et al. 2011, Zuccon et al. 2012, Barker et al. 2013). Euphoniinae, which at one time was part of Thraupidae, is sister to Carduelinae. Carduelinae can further be broken into five tribes, including Drepanini, the Hawaiian honeycreepers, which at times have been separated into their own family (James 2004, Lerner et al. 2011, Zuccon et al. 2012).
Conservation Status
Least Concern |
64.3%
|
---|---|
Near Threatened |
3.4%
|
Vulnerable |
3%
|
Endangered |
5.1%
|
Critically Endangered |
5.1%
|
Extinct in the Wild |
0%
|
Extinct |
7.7%
|
Not Evaluated |
0%
|
Data Deficient |
0.43%
|
Unknown |
11.1%
|
Data provided by IUCN (2023) Red List. More information
Related families
Fringillidae appears sister to the entire New World Nine Primaried Oscine radiation.