- Minnesota Breeding Bird Distribution
- Breeding Habitat
- Population Abundance
- Literature Cited
A regular breeding resident and migrant; occasionally individuals are observed during the winter months. The Field Sparrow was a common species during the Minnesota Breeding Bird Atlas (MNBBA).
The Field Sparrow is found from the northern Great Plains in eastern Montana south to central Texas and east from southern New England to northern Florida. It largely occurs south of the densely forested regions of the Great Lakes states and northern New England. Some of the Field Sparrow’s highest breeding densities occur in the central hardwoods of Kentucky, Missouri, and Tennessee and the mixed grass prairie of Nebraska (Figure 1).
Assigned a Continental Concern Score of 12/20 by Partners in Flight and classified as a Common Bird in Steep Decline; designated a Species in Greatest Conservation Need by the Minnesota Department of Natural Resources.
Only those birds that occur in the most northern reaches of its breeding range, including Minnesota, are migratory. Winters are spent in the southern United States.
A ground-foraging omnivore feeding largely on seeds and insects.
An open-cup nest. Early in the season, when the season’s foliage is still young, nests are located on or near the ground, hidden amid tufts of grasses or at the base of a small shrub. As the season progresses, new nests are established at greater heights in shrubs and small trees. Although some nests have been reported as high as 4 m above the ground, most are located within 1 m.
Roberts (1932) described the Field Sparrow as a locally common species in the southern third of the state. In the early 1900s it was most abundant in the southeastern counties from Goodhue south to Houston, but records occurred as far north as Sherburne and Isanti Counties in the east (rarely to southern Pine County) and as far north as Chippewa County in the west. It was still an uncommon species in southwestern Minnesota, having first appeared in Pipestone County in 1923. Although there were records farther north in the state, Roberts questioned their authenticity and assigned them to “errors in identification.” His staff at the University of Minnesota had carefully searched for the species in the central and northern regions of the state to no avail. Confirmed nesting records at the time (nests with eggs) were documented in Fillmore, Hennepin, Houston, Isanti, Sherburne, and Wabasha Counties; an inferred nesting record (nests and nest building) was available from Goodhue County.
Like many species that were common south of Minnesota, the Field Sparrow slowly expanded its range northward following the Mississippi River valley. Roberts first encountered the species in Ramsey County in 1884. By the late 1920s, when he was writing his treatise on Minnesota birds, the Field Sparrow was already established as a regular summer resident in the Twin Cities region.
Little had changed by 1975 when Green and Janssen published an updated account of the species. Summer records had been reported as far north as Otter Tail, Itasca, and southern St. Louis Counties, but nesting evidence was still confined to southeastern and east-central Minnesota. Several years later, in 1987, Janssen reported the species as a resident throughout southern and central Minnesota, although still most numerous in the southeastern and east-central regions. It also was “well represented” along the Minnesota River valley as far as the South Dakota border. Although nesting had yet to be confirmed north of Morrison County, an increasing number of reports from northern counties included Aitkin, Hubbard, and Itasca. Janssen identified 19 counties where nesting had been confirmed since 1970. Hertzel and Janssen (1998) would later add an additional 2 counties to the list.
The Minnesota Biological Survey reported a total of 570 breeding season locations for the Field Sparrow during the course of its field studies. Although reports in northern Minnesota remained rare, the species was reported at several locations in Hubbard County and as far north as southern Polk County. Records were common throughout southern Minnesota, including numerous records across the Prairie Coteau region in southwestern Minnesota (Minnesota Department of Natural Resources 2016).
During the MNBBA, observers reported a total of 1,039 Field Sparrow records in 11.3% (536/4,741) of the surveyed atlas blocks and in 15.0% (350/2,337) of the priority blocks. Breeding evidence was documented in 46 blocks (Figures 2 and 3; Table 1). The species was reported in 73 of Minnesota’s 87 counties (several blocks straddled Nicollet and adjacent counties along the Minnesota River; one block straddled Wright and Hennepin Counties) and were confirmed nesting in 32 counties. Three atlas blocks with confirmed nesting straddled 2 counties each: Hennepin/Wright, Blue Earth/Nicollet, and Brown/Renville. Of the counties where nesting reports had been confirmed, 16 had not been previously reported by Hertzel and Janssen (1998).
A probable breeding record was found as far north as southern Koochiching County, and several possible breeding records were found in Itasca, southern Beltrami, northern Hubbard, and northern Cass Counties. The northern limit of confirmed breeding occurred from Isanti and Sherburne Counties in the east to northern Morrison and central Otter Tail Counties in the central and western regions. The Field Sparrow was most frequently reported from the Paleozoic Plateau Subsection of southeastern Minnesota.
The MNBBA predicted distribution map illustrates that the highest breeding densities are predicted to occur in southeastern Minnesota, especially from Goodhue County south to Houston and Fillmore Counties (Figure 4). The Anoka Sandplain Subsection north of the Twin Cities, as well as portions of Washington County, also support moderately high densities with scattered pockets occurring as far north as Otter Tail and Wadena Counties. Overall, the Field Sparrow is predicted to be most frequently encountered in the Eastern Broadleaf Forest Province and along the Minnesota River valley. Scattered areas of higher abundance are also predicted in south-central and southwestern Minnesota. Although the MNBBA did not detect the species in the far northwestern corner of the state, the model suggests that suitable habitat may be available in small areas. The Manitoba breeding bird atlas, conducted between 2010 and 2014, did document the Field Sparrow in four blocks in the very southern region of the province, just north of Minnesota, including one probable breeding record (Bird Studies Canada 2017).
The accumulated evidence documents that the Field Sparrow has continued its northward range expansion in Minnesota at a rather slow pace over the past one hundred years. The expansive peatlands and dense forests of north-central and northeastern Minnesota, however, continue to provide a barrier to this open woodland and forest-edge species. Elsewhere in its breeding range, few large-scale changes have been noted in its overall distribution. Cutright et al. (2006) documented the species’ broad distribution across the southern two-thirds of Wisconsin, noting that the species has “presumably” always occurred in the state. Historic accounts of its presence in Michigan also document its common occurrence since the early 1900s throughout the Lower Peninsula and in the eastern and central regions of the Upper Peninsula. Recent atlases in the state have documented little change in its distribution in the past century (Chartier et al. 2013).
*Note that the definition of confirmed nesting of a species is different for Breeding Bird Atlas projects, including the definition used by the Minnesota Breeding Bird Atlas, compared with a more restrictive definition used by the Minnesota Ornithologists’ Union. For details see the Data Methods Section.