New World sparrows are a group of mainly New World
passerine birds, forming the family Passerellidae. They are seed-eating
birds with conical bills, brown or gray in color, and many species have distinctive head patterns.
Although they share the name sparrow, New World sparrows are more closely related to Old World
buntings than they are to the
Old World sparrows (family Passeridae). New World sparrows are also similar in both appearance and habit to
finches, with which they sometimes used to be classified.
Taxonomy
The genera now assigned to the family Passerellidae were previously included with the buntings in the family
Emberizidae. A
phylogenetic analysis of nuclear and
mitochondrial DNA sequences published in 2015 found that the Passerellidae formed a
monophyletic group that had an uncertain relationship to the Emberizidae.[1] Emberizidae was therefore split and the family Passerellidae resurrected.[2][3] It had originally been introduced, as the subfamily Passerellinae, by the German ornithologist
Jean Cabanis in 1851.[4]
Being a member of
Emberizoidea, New World sparrows have only nine easily visible
primary feathers on each wing (they also have a 10th primary, but it is greatly reduced and largely concealed).[7] Despite their name, not all of the New World sparrows resemble the typical image of a sparrow. Species in the
neotropics tend to be much larger with bold patterns of greens, reds, yellows, and grays. Those in the
Nearctic realm are smaller, with brown bodies streaked and with some head patterns.[8] Some even have
sexual dimorphism such as the
lark bunting and
eastern towhee.
Habitat and distribution
The New World sparrows are found throughout in the Americas, from their breeding ranges in the Arctic
tundra of North America to their year-round ranges in the
Southern Cone of South America. Given this huge expansive range, many species occupy different habitats such as grasslands, rainforests, temperate forests, and
deserts and xeric shrublands.[8] Those that breed in the northern parts of North America, such as the
white-throated sparrow and
Lincoln's sparrow, migrate further southward into the continent during the winter, while others like the
dark-eyed junco have been able to adapt to staying all year-round in some areas of North America. Most North American passerellid species usually migrate short distances. Some of the Southern Cone species move northward during autumn.[8] In the breeding season, sparrows of different species form small-to-medium flocks, as they do when foraging in the non-breeding season.
^Species in three monotypic genera were not sampled in the study: the
Sierra Madre sparrow (Xenospiza baileyi), the
Zapata sparrow (Torreornis inexpectata) and the
tanager finch (Oreothraupis arremonops)[6]
^Hall, K.S.S. (2005). "Do nine-primaried passerines have nine or ten primary feathers? The evolution of a concept". Journal of Ornithology. 146 (2): 121–126.
doi:
10.1007/s10336-004-0070-5.
^
abcDunne, P.; Karlson, K. T. (2021). Bird Families of North America. Houghton Mifflin Harcourt.