- Minnesota Breeding Bird Distribution
- Breeding Habitat
- Population Abundance
- Literature Cited
A regular nesting species, migrant, and accidental winter visitor in Minnesota. The Hermit Thrush was a common species during the Minnesota Breeding Bird Atlas (MNBBA).
Wide distribution in the upper midwestern and northeastern United States and Canada, and south in the Appalachian Mountains to the state of Virginia (Figure 1). Also found throughout the western United States and Canada. The highest densities occur in northern Wisconsin, northern Michigan, and northeastern Minnesota, plus in many isolated patches of Ontario, Nova Scotia, and northern Colorado.
Assigned a Continental Concern Score of 7/20 by Partners in Flight.
Short-distance migrant, winters in eastern, southeastern, and southern areas of the midwestern United States to northeastern Mexico.
Omnivore; insects, small invertebrates, and fruit primarily foraged on the ground.
Cup nest on the ground or slightly elevated in the base of a bush or small tree.
The Hermit Thrush was historically described as nesting in the northern evergreen forests of Minnesota, south to Isanti and Pine Counties and northwest to Itasca Park and Roseau and Lake of the Woods Counties (Roberts 1932). Roberts reported confirmed nests with eggs or nestlings in Cass, Itasca, Lake, and St. Louis Counties as well as at Itasca Park, plus nesting activity at Mille Lacs (young out of nest).
Over 40 years later, Green and Janssen (1975) described a similar distribution, though they more precisely suggested its southern distribution in Minnesota extended to the cities of Onamia in Mille Lacs County and Sturgeon Lake in Pine County. They reported additional counties with confirmed nesting records beyond those reported by Roberts, including Carlton, Cook, Lake of the Woods, and Roseau Counties. They also cited older breeding observations from Isanti, Otter Tail, and Washington Counties, but they emphasized that no current records existed from these areas. Janssen (1987) depicted a similar breeding distribution to that presented by Green and Janssen and confirmed nesting in 9 counties since 1970: Aitkin, Beltrami, Clearwater, Crow Wing, Hubbard, Itasca, Koochiching, Lake, and St. Louis. Several years later, Hertzel and Janssen (1998) added Roseau County to the list of counties with confirmed nesting since 1970 but excluded Clearwater County.
The extensive coverage of the Minnesota Biological Survey (MBS) recorded 1,178 breeding season locations for the Hermit Thrush. These locations reinforced its primary breeding distribution in northeastern Minnesota, but extended the Hermit Thrush breeding range considerably to include many potential breeding locations south to Kanabec, Mille Lacs, Morrison, Pine, and Todd Counties. Western breeding observations included one location each in Mahnomen and Otter Tail Counties, plus many locations in eastern Becker, northeastern Marshall, and Roseau Counties.
The MNBBA detected 2,691 records of the Hermit Thrush distributed extensively throughout the Laurentian Mixed Forest Province and a few locations in the Tallgrass Aspen Parklands (Figure 2). The overall breeding distribution was similar to the observations of the MBS, but no observations were included from Kanabec County and only one possible record was reported in the far northeastern corner of Otter Tail County. The MNBBA solidified the understanding of the species’ extensive distribution throughout northern Minnesota, with observations in Beltrami, Koochiching, and Lake of the Woods Counties, all counties where MBS has not yet completed its inventories.
The Hermit Thrush was recorded from 24.5% (1,162/4,751) of all blocks, including confirmed nesting in 1.4% (66 blocks) (Figure 3; Table 1). The only confirmed county nesting record not previously reported was from western Minnesota in Becker County, while probable nesting was also suggested for Mahnomen and Morrison Counties.
The current distribution of the Hermit Thrush may be larger than previously presented for Minnesota; however, the increase in its distribution may result from the more extensive coverage of the MBS and the MNBBA. The species is relatively easy to identify by sight and sound, making it unlikely to be missed. Yet, a definitive conclusion on whether the species breeding range has expanded in Minnesota is unclear.
The probability map for the Hermit Thrush identified high densities in the Agassiz Lowlands Ecological Subsection of northern Minnesota (Figure 4). Otherwise the breeding population was relatively evenly distributed throughout northeastern and north-central Minnesota but with patches of higher density noted in the Tamarack Lowlands Ecological Subsection of southwestern St. Louis County.
In their review of the Hermit Thrush in North America, Dellinger et al. (2012) commented on its potential range expansions in British Columbia, in some New England states, and in the southern Appalachian Mountains, but they mentioned no changes in the midwestern United States. The Wisconsin breeding bird atlas also found a southern range extension for the species from what had been previously reported (Cutright et al. 2006). Brewer et al. (1991) and Cadman et al. (1987) also suggested recent southern extensions as a result of their breeding bird atlases for Michigan and Ontario, respectively. These extensions appeared to be colonizations of coniferous patches, such as in spruce-fir forests and pine plantations. Based on these data, the Hermit Thrush should be searched for in suitable conifer patches in central and southerly locations of Minnesota during the June breeding season.
*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.