Bird Observer: The Birding Journal for New England

Bird Observer

The Birding Journal for New England

April 2016

Vol. 44, No. 2

Front Cover: April 2016

Chipping Sparrow by Barry van Dusen

An artist who has created many of our covers, Barry Van Dusen, lives in Princeton, Massachusetts, and is well known in the birding world. Barry has illustrated several nature books and pocket guides, and his articles and paintings have been featured in Birding, Bird Watcher’s Digest, and Yankee Magazine as well as Bird Observer. Barry’s interest in nature subjects began in 1982 with an association with the Massachusetts Audubon Society. He has been influenced by the work of European wildlife artists and has adopted their methodology of direct field sketching. Barry teaches workshops at various locations in Massachusetts. For more information, visit Barry’s website.

Chipping Sparrow

The Chipping Sparrow (Spizella passerina) is one of our most common and frequently heard songsters. Males, during the breeding season, sing their same-pitch trill incessantly throughout the day. Because they nest in rural and suburban habitats, many people frequently encounter these songsters.

In breeding plumage the Chipping Sparrow’s head pattern is distinctive. A white superciliary stripe separates the rusty crown from the black eye stripe that distinguishes it from all other sparrow species. The underparts are light gray and unstreaked, the upperparts are brown with black stripes and have tannish wing bars. Nonbreeding Chipping Sparrows are duller: the crown is streaked dark brown and the wing bars

are less distinct. In winter, adult Chipping and Clay-colored sparrows look similar but can be distinguished by their rump colors, gray in the former and buffy in the latter. Juvenile Chippies resemble winter adults but are heavily streaked below. Juvenile Clay- colored Sparrows look similar but have sparsely streaked breasts. Adult American Tree Sparrows have a dark breast spot; adult Chipping Sparrows have plain breasts. Five subspecies of Chipping Sparrows are generally recognized, with two occurring in the United States and Canada; S. p. passerina is the subspecies found in the east.

The Chipping Sparrow is a wide-ranging, largely migratory species, breeding from eastern Alaska across Canada to southern Newfoundland and across the United States south to near the Gulf Coast and southern California and Arizona. They are generally absent in the south central part of the United States. Southern states, particularly in the east, host year-round populations of Chipping Sparrow. Year-round populations occur in suitable habitat through Mexico and most of Central America. Migratory birds winter in the southernmost United States and the northern half of Mexico. In Massachusetts the Chipping Sparrow is a common breeder and migrant. It is a rare winter resident but in recent years has been recorded more frequently here. Chipping Sparrows migrate in flocks, often in mixed species flocks. They arrive in Massachusetts in April and early May, and leave in late September and October.

The breeding biology of the Chipping Sparrow is poorly known. They have long been considered monogamous but recent studies in Ontario, Canada, indicate that at least in some populations, males wander and copulate with females in neighboring territories and are sometimes polygynous. Chipping Sparrows often produce two broods per year and sometimes three. Only the male sings. The song is a trill of the same pitch. Both sexes utter a variety of chip notes that give the species its name. Males usually sing from perches in trees or shrubs and their song serves as territorial display and to attract females. In threat displays the head is lowered, the bill is open, the wings are drooping, the feathers are fluffed, and the bird shifts from side to side. Fighting sometimes follows threat displays with chases, bill thrusts, and often head to head flights up to 10 feet in the air, with much fluttering and harsh calls. Courtship involves song, chases, hopping along the ground, and pulling at vegetation that some suggest is symbolic of nest material collection.

Chipping Sparrows prefer grassy open woodland habitats and avoid mature forest. They appear to favor ornamental conifers for nesting. Males arrive on territory about a week before the females. The pair searches for nest sites together but the female makes the final choice. The nest is usually three to ten feet above the ground in a tree or shrub in clusters of leaves or conifer needles, but nests have been constructed in bizarre locations such as mowing machines and hanging baskets. The female constructs the nest, a flimsy cup of grasses and rootlets lined with hair and fine plant material. Only the female develops a brood patch and she alone incubates the usual clutch of four blue eggs spotted with various colors for the 11 days until hatching. The male may bring food to the female at the nest. The young are altricial, helpless, naked, and with eyes closed. The female does most of the brooding for about 11 days to fledging. Both parents feed the young and occasionally helpers have been observed. The parents continue to feed the young for about three weeks after fledging. If the female renests, the male takes over the feeding duties for the fledglings.

Chipping Sparrows forage mostly for seeds on the ground or in low vegetation. On the ground they run or hop, scratching through debris on lawns or fields. They also feed directly on the seeds of grasses and weeds. During breeding season they take insects and may eat fruit. In winter they forage in mixed-species foraging flocks and may forage in rolling flocks where birds at the back of the flock fly to the front to search for seeds until they are at the back of the flock again; they then repeat their flight to the front of the flock.

Chipping Sparrows are subject to the usual nest predators: snakes, crows, jays, and squirrels. Hawks and falcons prey on juveniles and adults. Chipping Sparrows also suffer extensive nest parasitism by cowbirds. They faced intense competition from House Sparrows in the early 20th century due to their use of human-altered habitats, but are probably more common now than in colonial times. Some populations declined in the 20th century, mostly due to reforestation. However, the species has adapted well to humans, their ornamental plants, and agriculture, and this together with their vast nesting range suggests that most populations of Chipping Sparrows are secure.

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