The Field Sparrow: A Life History

The Field Sparrow (Spizella pusilla) is a small songbird in the family Emberizidae (Order Passeriformes) that occurs throughout most of eastern North America.  It is one of the relatively few sparrows that commonly breed in the Southeast. 

Field Sparrow in summer

Distinguishing characteristics of the Field Sparrow include a short, pink bill; white eye-rings; white outer tail feathers; and a plain, unmarked breast.  The species is found in a variety of old fields, woodland edges, fencerows, and agricultural areas.  It begins courtship and mating in early spring, with males chasing females and defending territory from other males.  Males maintain and defend their territories through physical altercations between males as well as by their song, which is a warbling trill.  In addition to this song, the Field Sparrow has several alarm and flight calls that are used in a variety of contexts. 

Field Sparrow in winter

Nest construction begins in late April and extends through mid-May.  The nest, which is placed at a height of 9-300 centimeters in vegetation, is built solely by the female, and is composed of grasses, roots, hair, and other fine materials woven into a cup shape.  The eggs have a cream or white ground color, are marked with spots in various shades of brown, and have a smooth surface.  There are usually two to five eggs laid in a brood, and the female incubates for approximately twelve days.  The mostly naked, altricial nestlings are fed in the nest by both male and female parents for a period of about seven to eight days. 

The most frequent foods offered to the nestlings include many insects in both the adult and nymph stages, and various species of spiders.  After the young birds fledge, the parents will care for them until they reach independence at about one month of age.  The adult diet consists mainly of seeds, but some insects are taken, too.  

The Field Sparrow is a widespread species, ranging from southeast and northwest Montana, central Minnesota, southern Ontario, southern Maine, and southern New Brunswick; south to northeast Colorado, western Oklahoma and Kansas, central Texas and northern Mexico, and through the Gulf Coast to central Florida.  Some populations of the Field Sparrow are migratory, although most are not.  In the northernmost regions of its range, it is present only during the breeding season, and in the southernmost regions (such as the Gulf Coast and much of Florida), it is present only as a winter resident.  Be on the lookout for Field Sparrows in grassland and forest-edge habitats as the summer wanes and the fall season approaches!

Source:

Best, L. B.  1977.  Nesting biology of the Field Sparrow.  Auk 94(2):308-319.