- Minnesota Breeding Bird Distribution
- Breeding Habitat
- Population Abundance
- Literature Cited
A regular breeding resident and migrant; the Clay-colored Sparrow was a common species during the Minnesota Breeding Bird Atlas (MNBBA).
The Clay-colored Sparrow is confined to the interior of North America. It is found as far west as the mountain valleys of eastern British Columbia and Alberta, east to southern Ontario and Quebec, and south through the northern Great Plains and Great Lakes region. Small, disjunct populations occur north along Hudson Bay and James Bay. Abundant throughout much of its breeding range, high breeding densities are found in Canada’s Prairie Provinces and North Dakota (Figure 1).
Assigned a Continental Concern Score of 10/20 by Partners in Flight.
A short-distance migrant that winters primarily in the grasslands of southern Texas, southern Baja California, and the highlands of northern and central Mexico.
An omnivorous ground forager that consumes a variety of seeds and invertebrates.
An open-cup nest usually placed in a low shrub.
When Roberts wrote his account of the Clay-colored Sparrow in 1932, he considered it an abundant summer resident breeding throughout the state. “Indeed, nowhere in the state, except in the deep unbroken forest, is the Clay-colored Sparrow without a goodly representation.” He noted it was “especially abundant in the poplar belt bordering the Red River Valley on the east.” In the more densely forested landscape of north-central and northeastern Minnesota, it was equally numerous wherever “there are clearings, old ‘burns,’ windfalls, or other openings.” Confirmed nesting records (nests with eggs) stretched from Fillmore County in southeastern Minnesota; north to Hennepin, Isanti, McLeod, and Sherburne Counties in east-central Minnesota; west to Big Stone County; and north to Leech Lake and Itasca State Park and to Kittson, Marshall, Norman, Pennington, and Polk Counties in northwestern Minnesota. Inferred nesting reports (nests or adults carrying food) were reported in Goodhue and Mower Counties in southern Minnesota and the Mille Lacs region in northern Minnesota.
More than four decades later, Green and Janssen (1975) described the species’ statewide distribution but noted it was “very scarce” in southern Minnesota. Although Roberts had reported the sparrow from several southern counties in the late 1800s and early 1900s, no recent records had been reported south of Dakota and Lyon Counties. Janssen (1987) provided even more details regarding the species’ statewide distribution, noting it occurred primarily north of a line from northern Houston County west to Lincoln County. Abundance increased moving north except in the most densely forested regions of north-central and northeastern Minnesota. His distribution map excluded most of the southern tier of counties, although recent observations suggest that the species might be slowly reoccupying the region. He identified 21 counties in which nesting had been confirmed since 1970. Hertzel and Janssen (1998) later added another 11 counties to the list.
Field staff with the Minnesota Biological Survey (MBS) documented a total of 1,562 breeding season locations of the Clay-colored Sparrow statewide, including many records in southwest and south-central counties. Breeding season locations were identified in every county along the Iowa border except Fillmore. The species was still rare, however, in the Blufflands of southeastern Minnesota (Minnesota Department of Natural Resources 2016).
MNBBA participants reported 3,872 Clay‑colored Sparrow detections in 40.5% (1,933/4,767) of the surveyed atlas blocks and in 53.3% (1,246/2,338) of the priority blocks. Breeding evidence was documented in 187 blocks (Figures 2 and 3; Table 1). The species was reported from every county in the state and was confirmed breeding in 56 counties. Records were least common in north-central and far northeastern Minnesota as well in south-central and far southeastern Minnesota. Nevertheless, breeding was confirmed in several southern counties excluded from the distribution map presented by Hertzel and Janssen (1998), including Fillmore, Freeborn, and Jackson.
The MNBBA predicted distribution map predicted the highest breeding densities should be encountered in northwestern Minnesota, especially in the Tallgrass Aspen Parklands Province and in the Hardwood Hills and the Pine Moraines and Outwash Plains Subsections in west-central Minnesota (Figure 4). Shrubby wetlands scattered throughout the Agassiz Lowlands Subsection north of Red Lake also are predicted to support high densities. The area with the most suitable habitat in northeastern Minnesota is the location of the 2007 Ham Lake fire on the north end of the Gunflint Trail in Cook County. As Roberts (1932) noted earlier, the species is numerous in forest openings created by former fires.
The Clay-colored Sparrow appears to now occupy much of the state where it occurred more than one hundred years ago. Although it was scarce across southern Minnesota in the mid-1900s, it is now a regular species throughout that region, albeit in lower numbers than are encountered farther north. It may also be more common in the southern and western regions of the Laurentian Mixed Forest Province than it was decades ago because development has fragmented much of the formerly extensive forest landscape in the region.
Since the early 1900s, the Clay-colored Sparrow has gradually expanded its range to the north and east throughout North America as logging and farming activities opened up densely forested landscapes. The species expanded its range east across Ontario over a period of 75 years (Cadman et al. 2007). It reached southwestern Quebec in 1960 and was documented as a breeding species in 1975. Now it is broadly distributed throughout the southern third of the province (Quebec Breeding Bird Atlas 2016) and continues to expand eastward to the Maritime Provinces and New England (Grant and Knapton 2012). Along the northwestern periphery of its breeding range, in British Columbia, populations are expanding further west throughout the southern region of the province (Ryder 2015).
*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.