- Minnesota Breeding Bird Distribution
- Breeding Habitat
- Population Abundance
- Literature Cited
A regular breeding resident and migrant in wet sedge and grasslands in northwestern and northcentral Minnesota. The Nelson’s Sparrow was rare during the Minnesota Breeding Bird Atlas (MNBBA).
This subspecies has a restricted breeding range from Minnesota and South Dakota to northwestern Alberta, with the highest densities in North Dakota (Figure 1).
Assigned a Continental Concern Score of 14/20 by Partners in Flight and designated a Watch List species. It is also designated by the Minnesota Department of Natural Resources as a Species in Greatest Conservation Need.
Short-distance migrant that overwinters in marshes along the Atlantic and Gulf Coasts.
Insects, arthropods, mollusks, and seeds.
Cup nest on or near the ground, often partly or fully domed.
Roberts (1932) described the Nelson’s Sparrow as a summer resident that breeds in northwestern Minnesota, but he emphasized the possibility of nesting throughout the southern portion of Minnesota as well. He documented many reports from the southern and western portions of the state (e.g., Blue Earth, Dodge, Hennepin, Isanti, Jackson, Lac qui Parle, Lincoln, Norman, Otter Tail, Renville, and Waseca Counties), but all except a June observation in Blue Earth County were in April, May, July, and September. Therefore, most could have been migratory birds. June observations were also recorded in northwestern Minnesota in both Marshall and Kittson Counties, though only a nest with three eggs was confirmed in Kittson County. According to Breckenridge (1930), the nest was found in a very wet, boggy marsh and only after a considerable effort on June 21, 1929.
Green and Janssen (1975) emphasized that the species only resides in the northwestern region of the state. They included confirmed nesting in Kittson County and inferred nesting in Clay, Mahnomen, and Marshall Counties. Janssen (1987) noted that until 1974 it was presumed restricted to northwestern Minnesota from Clay to Kittson Counties. However, he points out new potential nesting activity of the Nelson’s Sparrow in Minnesota as follows: 1) a nest found by Burt (1978) during a “week-long search for Yellow Rail nests” in late June at the McGregor Marsh in Aitkin County, 2) observations during the breeding season in western Roseau and Pennington Counties by Eckert (1980) in surveys of prairie tracts, and 3) observations during the 1982 nesting season in Becker, Cass, and Polk Counties. Janssen (1987) and Hertzel and Janssen (1998) identified Aitkin and Marshall Counties as the only two counties where confirmed nests have been found since 1970.
The Minnesota Biological Survey (MBS) recorded 115 locations of Nelson’s Sparrow during its county surveys (Minnesota Department of Natural Resources 2016). The excellent MBS observers have greatly expanded the potential breeding range of the species in Minnesota, including a total of 16 counties with breeding season locations (Minnesota Department of Natural Resources 2017). These locations ranged from Kittson and Roseau Counties in northwest Minnesota and south to Douglas, Lac qui Parle, Morrison, Otter Tail, Swift, Todd, and Wilkin Counties. They also recorded locations in north-central Minnesota, including several in the McGregor area, two locations in Itasca County, and multiple locations east of Leech Lake in Cass County. Scattered breeding observation locations were also identified in southern Beltrami, Hubbard, Red Lake, and Wadena Counties, as well as east to St. Louis County.
The MNBBA included breeding records from 58 blocks with a similar but not quite as extensive breeding range as indicated by the MBS (Figure 2). Probable breeding was recorded in Roseau County in the northwest, the counties of Clay, Polk, and Wilkin in the west, and Cass County to the east (Figure 3; Table 1). Most of the remaining breeding observations were of possible nesting (81.0%, 47/58) in Aitkin, Becker, Beltrami, Crow Wing, Grant, Kittson, Lac qui Parle, Pennington, Pope, Red Lake, and Wadena Counties. No confirmed nests were found.
The collective evidence from these observations suggest the Nelson’s Sparrow is more widely distributed in Minnesota than previously thought. Yet its distribution is sparse and localized in wet meadows and marshes—often in relatively large complexes that are difficult to access. Breckenridge’s (1930) description of the nest he found was in a marsh in Kittson County “two square miles in extent.” The description by Burt (1978) of the nest he found in the extensive McGregor Marshes of Aitkin County was in knee-deep water and hidden under a tuft of grass. Both amply illustrate the challenges of finding nests or even observing the species.
The Manitoba breeding bird atlas identified numerous confirmed, probable, and possible nesting in the southern and southeastern part of the province. The federal Breeding Bird Survey (BBS) indicated the highest densities are found in central North Dakota (Figure 1). Cutright et al. (2006) confirmed nesting in Wisconsin at Crex Meadows in Burnett County in 1999, a place where many summer observations had been previously recorded. In addition, one probable nesting was also recorded from Vilas County in extreme northern Wisconsin. This species should be sought in large sedge and grass meadows throughout Minnesota. Visual identification can be a challenge in these habitats, and its faint song is frequently only vocalized at night. In his review of the Nelson’s Sparrow in North America, Schriver et al. (2011) does not suggest any changes in the species’ historical breeding distribution, except to suggest a southern extension along the Atlantic Coast of the A.n. subvirgatus subspecies maritime population in northeastern North America.
*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.