- Minnesota Breeding Bird Distribution
- Breeding Habitat
- Population Abundance
- Literature Cited
A regular breeding species and migrant, the Least Flycatcher was common in abundance during the Minnesota Breeding Bird Atlas (MNBBA).
Widely distributed and common across the northern United States and Canada to the tree limit, including south in the Appalachian Mountains to northern Georgia. Highest densities have been recorded in northern Minnesota and on the North Dakota border with Manitoba and Saskatchewan (Figure 1).
Assigned a Continental Concern Score of 11/20 and listed as a Common Species in Steep Decline by Partners in Flight.
Long-distance migrant, winters from Mexico to Central America.
Almost exclusively flying insects; occasionally gleans from foliage.
Saplings, subcanopy, and canopy; usually in deciduous tree species.
According to Roberts in 1932, the Least Flycatcher was “one of the most common and widely distributed birds of the state.” He reported nesting activity from Jackson and Fillmore Counties on the border with Iowa, to Kittson County in extreme northwestern Minnesota, and to Itasca County in northern Minnesota. He emphasized the species was “breeding throughout the state” but did not report any nests from northeastern Minnesota.
More than 40 years later, Green and Janssen (1975) described the species’ distribution in a similar fashion, simply stating that it is a resident throughout the state and “frequents groves on the prairies.” A few years later, Janssen (1987) echoed this distribution but also stated that the species was “scarce to absent in many areas of the south-central and southwest regions.” He reported confirmed nesting from 22 counties, including the northeastern counties of Cook, Lake, and St. Louis. Hertzel and Janssen (1998) added another 4 counties with confirmed nesting records since 1970. Collectively the confirmed nesting records include the heavily forested areas of the northeast, north-central, and southeastern regions of the state. Records were scarce in the southwestern and southern counties; Brown County was the only county with a confirmed nesting in these areas.
The Minnesota Biological Survey (MBS) included 1,627 breeding season locations in its detailed surveys of counties (Minnesota Department of Natural Resources 2016). The highest density of locations was in northeastern and north-central Minnesota, but locations were scattered throughout the state. For instance, locations were noted in the extreme southwestern counties of Lincoln (4 locations), Murray (2), and Rock (2). However, numerous counties had no records, such as Lyon, Nobles, Pipestone, and Watonwan.
The MNBBA further substantiated the widespread distribution of the species in the state with 3,774 breeding records and at least possible nesting from every county (Figure 2). The participants of the MNBBA recorded nesting activity in 43.3% (2,051 of 4,741) of the surveyed atlas blocks and 55.8% (1,305 of 2,337) of priority blocks. These included 75 confirmed nesting records, 60 of which came from priority blocks (Figure 3; Table 1). A total of 31 counties had confirmed nesting records. Nesting records were more densely distributed in the northern forested portion of the state. However, possible or probable nesting was also quite substantial in many southwestern and western counties. Breeding records were sparse in most of the southern counties, but small populations can still be found in wooded areas of this region.
The predicted distribution map for the Least Flycatcher highlighted potentially high densities in north-central and northwestern Minnesota and in many other areas of northern Minnesota (Figure 4). These areas generally correspond with forested habitats that are dominated by deciduous trees or mixed deciduous-coniferous forests, such as the Tallgrass Aspen Parklands Province in the northwest, the Pine Moraines and Outwash Plains Subsection in west-central Minnesota, and the Western Superior Uplands Section in the east-central region.
In a summary of the Least Flycatcher in North America, Tarof and Briskie (2008) identified few changes in its distribution except for an expansion into Washington State since the late 1970s. The low detection of the species in the southern portions of Minnesota renders Roberts (1932) comment that it is the “most generally and evenly distributed member of its family” as no longer true. This change is also supported by Robbins (1991), who observed that the Least Flycatcher has been moving northward in Wisconsin as mature deciduous forest cover has declined in the south.
*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.