Sparrows and finches

Sparrow and Finch Facts

Classification:

• Kingdom: Animalia
• Phylum: Chordata
• Subphylum: Vertebrata
• Class: Aves
• Order: Passeriformes
• Families: Fringillidae (chaffinches, finches, grosbeaks, euphonias, chlorophonias); Emberizidae (buntings, American sparrows); Passaridae (Old World sparrows); Cardinalidae (cardinals)
• Subfamilies: Carduelinae (rosy finches, crossbills, redpolls, siskins, some grosbeaks, saltators, Hawaiian honeycreepers); Fringillinae (chaffinches, bramblings, goldfinches), Geospizinae (Darwin’s finches); Emberizidae (American sparrows, juncos); Calcariidae (longspurs, snow buntings); Cardinalidae (cardinals)
• Geographical distribution: All continents, except Madagascar and South Pacific islands
• Habitat: Prefer temperate regions, although some species are found in Arctic, desert, tropic, and subtropical regions
• Gestational period: Varies by species, but most eggs are incubated for eleven to fourteen days
• Life span: Varies; three to ten years in the wild, five to eight years in captivity
• Special anatomy: Beaks adapted for gathering, holding, crushing, and eating seeds; finches have nine primary wing feathers and twelve tail feathers; melodious song

The name “finch” at one time was applied to ten different subfamilies of songbirds such as the chaffinches, goldfinchlike birds, buntings, grosbeaks, tanagers, weaver-birds, and sparrows. All of these birds have large jaw muscles that power cone-shaped bills. They differ, however, in skull structure and in the ways they open seeds. These differences suggest that at least some “finches” may have evolved independently and share characteristics as a result of convergent evolution. In view of these differences, most modern taxonomists agree that the name “finch” should be limited to the family Fringillidae in the order Passeriformes.

The 218 species of Fringillidae family are among the most successful of the seed-eating passerines. All have conical bills or crossed bills adapted for eating seeds. Several fringillid subfamilies are recognized. The subfamily Carduelinae includes the rosy finches, crossbills, redpolls, siskins, and some grosbeaks. Chaffinches and bramblings are placed in the subfamily Fringillinae. Hawaiian honeycreepers (subfamily Drepanidinae), which are restricted to the Hawaiian Islands, were once categorized in the subfamily Drepanidinae but have been placed in the Carduelinae subfamily due to their similarities to the Carpodacus genus. Darwin’s finches, which are found only on the Galápagos Islands, belong to the subfamily Geospizinae.

Several finchlike birds were reclassified in the Emberizidae family in the 1990s. This family is further subdivided into more than seventy different genera, which includes buntings, American sparrows, brush-finches, juncos, and towhees..

Old World sparrows, which include the familiar house sparrow (Passer domesticus), are more distantly related and placed in a separate family called the Passeridae. They are widespread seed eaters that occur in a wide variety of habitats throughout most of Eurasia and North Africa. Some, such as the house sparrow, have been deliberately and successfully introduced in many other areas of the world.

The Ecology of the Finches

Most finches are forest-dwelling, seed-eating songbirds that have nine instead of ten primary feathers in the wing and twelve tail feathers. The outermost part of ten primary feathers is usually small and hidden.

Most species have sweet, melodious songs and often sing in winter, which is why they were named finch (from Latin frigus, “cold,” because finches sing in the cold of winter). The female builds an open, cup-shaped nest with her tail feathers and also uses the feathers to incubate the eggs. Incubation and the fledgling period usually last between eleven and fourteen days. Members of Fringillidae feed insects to their young and inhabit large territories while breeding. There are usually about three or four eggs and they are blue-gray with purple-brown spots. In the summer, the birds eat caterpillars from trees, and in winter seeds from farmland, including spilled grain and weed seeds. Over most of their territory they are migratory, but females tend to move farther away from their territory than males.

The Carduelinae form the largest branch of the finch family, with more than 150 species in 49 genera. These birds are more specialized seed-eaters and they feed their young mostly seed, sometimes augmented with insects. They nest either alone or in loose colonies and feed away from the nest in packs. Many feed directly on plants and are adept at clinging to stems or hanging on twigs. They demonstrate a wide range in bill shape and adaptation for extracting the seeds from different types of seed pods. The fringillids range in size from the Mycerobas Palearctic grosbeaks of the Himalayas, which reach eight inches in length and 3.5 ounces in weight, to the relatively tiny Lawrence’s goldfinch (Spinus lawrencei) of eastern North America, which just reaches four inches in length and weighs no more than 0.3 ounce. The Hawaiian honeycreepers are now classified in the Carduelinae subfamily; they were previously classified in the Drepanididae subfamily.

Most fringillids are found in temperate regions, with fewer in the Arctic, deserts, tropics, and subtropics. About sixty-eight species occur in Eurasia, thirty-six in Africa, and twenty-five in the New World. Fringillids are absent only from Madagascar and the islands of the South Pacific. Some species have been introduced into Australia and New Zealand.

Sparrows

The twenty-six species of sparrows are closely related to sparrow-weavers and were once grouped with them in the family Ploceidae before being placed in their own family. They are all small, seed-eating birds that occupy a wide variety of habitats throughout Eurasia and Africa. Over half of the true sparrows (Passer) coexist well in human habitations and at least one, the house sparrow, has for so long adapted to exist in human-modified landscapes that it is no longer found naturally in the wild. House sparrows coexist with humans in habitats and climates ranging from tundra to tropics. Other Passer species occur in habitats as diverse as desert, woodlands, or tropical rain forests. Dry brush country and mountain habitats are occupied by species of rock sparrows (Petronia), which may range upward of fifteen thousand feet in the Himalayas.

Males claim nest sites and sing to attract females and deter other males. Following pair formation both sexes help build the nest. Many Passer species, such as Eurasian tree sparrows (Passer montanus), are solitary nesters, usually nesting in tree cavities, but some are at least partly social and nest in loose aggregations. Several species also build a ball-shaped nest with a feather-lined interior and an entrance toward the side. Depending on species, from two to eight whitish or mottled eggs are laid in a clutch, generally fewer in the tropics and more in temperate zones. Incubation is brief, generally eleven or twelve days, and the young remain in the nest for another two weeks (up to seventeen days). The young are fed on a variety of foods, mostly seeds and insects, but discarded bits of human food, grains, and other discarded edible substances are often readily used to feed the young.

Tropical sparrows generally raise one brood a year, but temperate species may raise two or three broods or occasionally even four broods in good weather conditions and availability of sufficient food. Following breeding, the sparrows are gregarious, gathering in loose aggregations of foraging flocks that may include other species. In many locales their numbers may cause appreciable destruction of seed crops.

Some Typical Finches and Sparrows

The northern cardinal (Cardinaliscardinalis), in the Passeriformes order, belongs to the family Cardinalidae. Males are bright “cardinal” red with black about the bill. Females are a duller brown-red. Both have a distinctive crest. The species is widespread throughout eastern North America, in western North America from the Great Plains south and west into California, Arizona, New Mexico, Texas, and into Mexico. It is essentially nonmigratory and winters in the same general area. The cardinal’s range has expanded northward in recent years, especially into New England, and it has been successfully introduced in Hawaii and Bermuda.

Cardinals dwell in mostly edge habitats, especially the interface of woodland and meadow, and edges of swamps of shrubby wetlands, especially areas that offer shrubby evergreens for nesting. They have adapted well to human-modified landscapes and commonly nest in landscaped yards in which the mix of ornamentals and grass essentially mimics its natural habitats.

One of the earlier nesting species, cardinals may claim their territories in late February. The female typically constructs a nest of leaves, weeds, grasses, and thin bark strips in dense shrubbery, often in either evergreens or vine tangles from one to twenty feet high, but generally lower. Clutch size is generally three or four spotted white eggs which hatch in about twelve to fourteen days. Three broods may be raised in a season in southern states, about two broods in more northerly states. The young are fed seeds and small insects. Adults divide roles and responsibilities to raise a second and sometimes a third family; the male cares for the first brood while the female incubates the second brood. The young and adults also form family groups that may remain together in fall. Groups often form loose flocks of up to seventy birds in winter. Cardinals are common birds at feeders.

The American goldfinch (Spinus tristis) belongs to the family Fringillidae. It is widespread in North America, breeding from southern Canada southward to Gulf Coast states, west to California. At least partially migratory, it winters along the Gulf Coast and Florida but may winter anywhere in its breeding range in mild winters.

The American goldfinch is a bird of fields and open woodlands. It is a late-nesting species, often not beginning until August in its northern range, late May or June in western and more southern states. Nests are constructed in branch forks, often from one to thirty feet high. The highly compact, cup-shaped nests are lined with thistle or thistledown and are so tightly constructed that they hold water—young sometimes drown following heavy rainstorms when the nest is flooded. Generally four to six (usually five) bluish eggs are laid and incubated by the female for about two weeks. The male attends the incubating female at the nest, bringing her food.

Young are fed by regurgitation as the parents first fill their crops with dandelion, burdock, thistle, or chicory seeds, berries, and insects, then regurgitate or cough them up to feed each of the young. Seeds are usually augmented by insects, especially caterpillars, grasshoppers, aphids, and plant lice.

The house sparrow (Passer domesticus) belongs to the family Passeridae. It is the most widely distributed of sparrows, ranging across Eurasia and Africa and successfully introduced in South America and Australia. Repeated introductions of birds in North America between 1850 and 1867 resulted in the establishment of this aggressive songbird. By the early twentieth century, it was probably the most abundant bird in North America but has declined with the switch to combustion engine vehicles, for it fed on the scattered feed grain fed to horses. The house sparrow gathers in large winter roosts in urban and suburban areas or evergreen plantations.

House sparrows are aggressive cavity nesters. Their success has at least partly been at the cost of other cavity nesters such as bluebirds and swallows, also Passeriformes, of the Turdidae and Hirundinidae families, respectively. Nesting sites are selected in cultivated areas, especially buildings, outbuildings, farms, and edge habitat between urban and suburban landscapes and natural landscapes. Artificial cavities, including nest boxes, are also readily appropriated by this adaptable species. The nest of small twigs and leaves is lined with grasses, feathers, hair, and bits of paper and other discarded materials. The four to six white or greenish eggs are incubated for about fourteen days. Young are brooded by the female and fed mostly insects and spiders, along with seeds and blossoms.

Principal Terms

convergent evolution: unrelated animals that have evolved similar features which enable them to exploit a habitat in a similar fashion, and have the same way of life

Passeriformes: the largest order of birds, consisting mostly of perching songbirds

primary feathers: feathers of the hand that provide most of the lift and thrust for bird flight

Bibliography

Austin, O. L., Jr. Life Histories of North American Cardinals, Grosbeaks, Buntings, Towhees, Finches, Sparrows, and Allies. 3 vols. 1968. Print.

Byers, C., J. Curson, and U. Olsson. Sparrows and Buntings: A Guide to the Sparrows of the World. Boston: Houghton Mifflin, 1995. Print.

Clement, Peter. Finches and Sparrows. Princeton, N.J.: Princeton University Press, 1999. A well-illustrated, comprehensive guide to sparrows and finches.

Rising, J. D. Sparrows of the United States and Canada. New York: Academic, 1996. Print.

Tietze, Dieter Thomas. "Complete Phylogeny and Historical Biogeography of True Rosefinches (Aves: Carpodacus)." Zoological Journal of the Linnean Society 169.1 (2013): 215-34. Print.

Zuccon, Dario, et al. "The Phylogenetic Relationships and Generic Limits of Finches (Fringillidae)." Molecular Phylogenetics and Evolution 62 (2012): 581-96. Print.