the chipping sparrow (spizella passerina) is a species of american sparrow , a passerine bird in the family emberizidae .
it is widespread , fairly tame , and common across most of its north american range .
there are two subspecies , the eastern chipping sparrow and the western chipping sparrow .
this bird is a partial migrant with northerly populations flying southwards in the fall to overwinter in mexico and the southern united states , and flying northward again in spring .
it molts twice a year .
in its breeding plumage it has orangish-rust upper parts , gray head and underparts and a distinctive reddish cap .
in non-breeding plumage , the cap is brown and the facial markings are less distinct .
the song is a trill and the bird has a piercing flight call that can be heard while it is migrating at night .
in the winter , chipping sparrows are gregarious and form flocks , sometimes associating with other bird species .
they mostly forage on the ground for seeds and other food items , as well as clambering on plants and trees , feeding on buds and small arthropods .
in the west of their range they breed mainly in coniferous forests , but in the east , they choose woodland , farmland , parks and gardens .
breeding starts in late april and may and the nest is often built in a tree .
throughout the year , adults 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 eyebrow are variable but generally obscure in juveniles .
the song is a trill that varies considerably among birds within any particular region .
two broad classes of variation in the song of the chipping sparrow are the fast trill and the slow trill .
individual elements in the fast trill are run together about twice as fast as in the slow trill; the fast trill sounds like a buzz or like someone snoring , whereas the slow trill sounds like rapid finger-tapping .
individual elements in the trill are very similar to a high pitch chi chi chi call .
the flight call of the chipping sparrow is heard year-round .
its flight call is piercing and pure-tone , lasting about 50 milliseconds .
it starts out around 9 khz , then falls to 7 khz , then rises again to 9 khz .
the flight call may be transliterated as seen? chipping sparrows migrate by night , and their flight calls are a characteristic sound of the night sky in spring and fall in the united states .
in the southern rockies and eastern great plains , the chipping sparrow appears to be the most common nocturnal migrant , judged by the number of flight calls detected per hour .
on typical nights in august in this region , chipping sparrows may be heard at a rate of 15 flight calls per hour .
on better-than-average nights , chipping sparrows occur at a rate of 60 flight calls per hour , and on exceptional nights chipping sparrows' flight calls are heard more than 200 times per hour .
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 .
at least two subspecies of chipping sparrows occur in western north america .
the widespread spizella passerina arizonae is associated with mountains and arid habitats of the western interior .
a pacific slope population constitutes subspecies s .
p .
stridula .
although these two races are both western , and are often lumped together as the western chipping sparrow , they do not necessarily form a single entity that stands apart from the eastern chipping sparrow (s .
p .
passerina) .
in eastern north america , chipping sparrows breed in woodlands , farmlands , and suburban and urban districts .
in western north america , the chipping sparrow prefers conifer forests for breeding .
the chipping sparrow is partially migratory , with almost all mid-latitude and high-latitude breeders withdrawing in winter to the southern united states and mexico .
on the wintering grounds and during migration , chipping sparrows are gregarious , forming tight flocks with other chipping sparrows or loose assemblages with other species such as eastern bluebirds and pine warblers .
throughout the year , chipping sparrows forage on the ground , often in loose flocks .
their diet consists mainly of seeds and crumbs of mostly any food , especially those fallen on the ground .
chipping sparrows frequently forage directly from forbs and grasses , too .
at any time of the year , especially , in spring , chipping sparrows may be seen in trees , even up in the canopy , where they forage on fresh buds and glean for arboreal arthropods .
although they are wary , chipping sparrows often allow close approach .
a quiet observer can often get to within 50100 feet of one or more chipping sparrows feeding on the ground .
when spooked , chipping sparrows fly a short distance to the nearest tree or fencerow .
in early spring , the first migrants return from their wintering grounds in march , but the bulk of migrants arrives throughout april .
males set up territories right away , and their trilled songs make them conspicuous .
breeding begins as early as april , but again , most nesting activity occurs from late april to early may onwards .
molt in the chipping sparrow follows the "complex alternate strategy" as usual for american sparrows .
it consequently has two molts per year as adults and three molts in their first year of life , also called their first plumage-cycle .
the chipping sparrow's two adult molts occur in late summer and late winter .
