The Chipping sparrow (Spizella passerina) is a species of New World sparrow widespread across most of its North American range. Chipping sparrows vary across their extensive North American range. There is minor geographic variation in appearance, and there is significant geographic variation in behavior. Ornithologists often divide the chipping sparrow into two major groups: the Eastern chipping sparrow and the Western chipping sparrow. However, there is additional plumage and behavioral variation within the western group.
Throughout the year, adult Chipping sparrows are gray below and an orangish-rust color above. Adults in alternate (breeding) plumage have a reddish cap, a nearly white supercilium, and a black trans-ocular line (running through the eye). Adults in basic (nonbreeding) plumage are less prominently marked, with a brownish cap, a dusky eyebrow, and a dark eye-line. Juvenile Chipping sparrows are prominently streaked below. Like non-breeding adults, they show a dark eye-line, extending both in front of and behind the eye. The brownish cap and dusky eyebrows are variable but generally obscure in juveniles.
Chipping sparrows are found across most of North America. They are partial migrants with northerly populations flying southwards in the fall to overwinter in Mexico and the southern United States, and flying northward again in spring. Chipping sparrows inhabit taiga, forests, open woodlands, shrubland, thickets, pastures, and urban areas. In the west of their range, they breed mainly in coniferous forests, but in the east, they choose woodland, farmland, parks, and gardens.
In the winter, Chipping sparrows are gregarious birds. They form flocks and sometimes associate with other bird species. Chipping sparrows are active during the day spending most of the time foraging on the ground for seeds and other food items. They may also clamber on plants and trees to feed on buds and small insects. Chipping sparrows prefer to forage in covered areas, often near the edges of fields. The birds communicate with each other vocally and also use visual displays. Their common call is a sharp 'chip' often produced during foraging. The song is a trill that varies considerably among birds within any particular region. The flight call of Chipping sparrows is heard year-round; it is piercing and pure-tone and may be transliterated as 'seen'.
Chipping sparrows are herbivores (granivores, graminivores). They feed mainly on seeds, grasses, herbs, and occasionally small berries. During the breeding season, they hunt insects and may also take spiders.
Chipping sparrows are considered monogamous (one male to one female). However, they may also exhibit polygynous behavior when males mate with more than one female. Males start arriving at the breeding grounds from March (in more southern areas, such as Texas)) to mid-May (in southern Alberta and northern Ontario). Females arrive one to two weeks later, and males start singing soon after to find and court a mate. After the pair is formed, nesting begins (within about two weeks of the female's arrival). Overall, the breeding season is from March till about August. Chipping sparrows breed in grassy, open woodland clearings and shrubby grass fields. The nest is built in a tree or bush. The nest itself is constructed by the female in about four days. It consists of a loose platform of grass and rootlets and an open inner cup of plant fiber and animal hair. The female lays a clutch of 2 to 7 pale blue to white eggs with black, brown, or purple markings. They are incubated by the female for 10 to 15 days. The chicks hatch altricial; they are naked, blind, and helpless. They are fed by both parents for 9-12 days. By this time the chicks are ready to leave the nest but both parents continue to feed them for about 3 weeks more. At the age of 1 year, young Chipping sparrows become reproductively mature and start to breed.
Chipping sparrows are common and widespread across their range. However, their nests are often brood parasitized by Brown-headed cowbirds and this usually results in the nest being abandoned.
According to the What Bird resource, the total population size of the Chipping sparrow is around 1 billion individuals. According to the All About Birds resource the total breeding population size of this species is 230 million breeding birds. Overall, currently Chipping sparrows are classified as Least Concern (LC) on the IUCN Red List and their numbers today are increasing.
