- Minnesota Breeding Bird Distribution
- Breeding Habitat
- Population Abundance
- Literature Cited
A regular breeding resident and migrant; the American Redstart was an abundant species during the Minnesota Breeding Bird Atlas (MNBBA).
Widely distributed across Canada’s boreal forest, the American Redstart is absent only from portions of southern Alberta and southern Saskatchewan. In the United States, it is found in the northern Rockies and east of the Great Plains. It is absent from the southern coastal plain, including most of Florida, and from portions of Kentucky and Tennessee. Some of the highest breeding densities are found in British Columbia, in Minnesota east through the northern Great Lakes, and in the Maritime Provinces (Figure 1).
Assigned a Continental Concern Score of 10/20 by Partners in Flight.
A long-distance migrant that winters in the Caribbean, Central America, and northern South America.
An insectivore that secures prey items by hovering, gleaning, fly-catching, and flushing prey by flashing its wings and tail.
Open-cup nest placed in a deciduous shrub or tree at variable heights anywhere from 1 to 20 m or higher.
Roberts (1932) described the American Redstart as an abundant and widely distributed species across Minnesota:
Go where one will in heavily timbered regions, the Redstart is sure to be there and usually in considerable numbers, though it may be easily overlooked because of its diminutive size and small voice. In some localities, as on the wooded islands of the Mississippi River bottom-lands where they border the state on the southeast, it frequently outnumbers all other small birds put together.
The species was also found in small woodland groves on the prairie, though in considerably fewer numbers. Confirmed breeding records (nests with eggs) were available from Goodhue, Hennepin, and Otter Tail Counties; inferred breeding records (e.g., nests or feeding young out of nest) were available from Cass, Cook, and Ramsey Counties and from the Mille Lacs and Leech Lake regions.
Forty years later, Green and Janssen (1975) also described the redstart as a breeding resident throughout the state but characterized it as “very scarce south of the Minnesota River, from Blue Earth and Faribault counties westward.” Janssen (1987) included a distribution map that eliminated the southwestern corner of the state, from Lac qui Parle County southeast to western Freeborn County, and stated it was scarce to entirely absent from this region. He also delineated 27 counties where nesting had been confirmed since 1970. A few years later Hertzel and Janssen (1998) would add an additional five counties to the list, including Brown County in south-central Minnesota, south of the Minnesota River valley.
Beginning in the late 1980s, field staff with the Minnesota Biological Survey have documented 1,522 American Redstart breeding season locations. Although absent from the most heavily cultivated regions of western Minnesota, the species was common in the floodplains of the Minnesota River Valley. Scattered records also were documented across southwestern and south-central Minnesota (Minnesota Department of Natural Resources 2016).
During the Minnesota Breeding Bird Atlas, participants reported 4,069 American Redstart records from 45.3% (2,150/4,748) of the surveyed atlas blocks and from 57.8% (1,350/2,337) of the priority blocks. Breeding evidence was reported in 169 blocks (Figures 2 and 3; Table 1). Widely distributed throughout all but the Prairie Parkland Province, the American Redstart appears to have become more common in the western regions of the state. It now can be found in floodplain forests along the entire length of the upper Minnesota River valley, small woodlots in the Red River valley, and in southwestern Minnesota. Indeed, records were reported from all but 2 of Minnesota’s 87 counties: Nobles and Martin, both located along the Iowa border in southwestern Minnesota. Breeding evidence was documented in 53 counties; one block straddled 2 counties (Le Sueur and Nicollet). Twenty-six of the counties were additions to the list published by Hertzel and Janssen (1998). Among the 29 warbler species that regularly breed in Minnesota, the American Redstart was the fifth most abundant species during the MNBBA, preceded by the Common Yellowthroat, Ovenbird, Yellow Warbler, and Nashville Warbler.
Atlas data were used to generate a graphic model predicting the relative abundance of the American Redstart throughout Minnesota (Figure 4). Highest breeding densities are predicted to occur along the Mississippi River valley and its tributaries in southeastern Minnesota and throughout the northern reaches of the Eastern Broadleaf Forest Province and the southern portions of the Laurentian Mixed Forest Province. Outside of major metropolitan areas, such as the Twin Cities and Rochester, lowest densities are predicted to occur in the intensively cultivated regions of south-central Minnesota, the Red River valley, and pockets of far north-central Minnesota.
The status of the American Redstart in Minnesota appears to have changed little in the past hundred years. As the prairie sod was converted to productive agricultural land, suitable habitat was likely at a premium in the early to mid-1900s, when Green and Janssen (1975) and Janssen (1987) noted its scarcity in southwestern Minnesota. Although it remains an uncommon species in some of the most intensively cultivated counties, some suitable habitat is now present in small patches in these areas.
Few major shifts in the redstart’s breeding distribution have been documented elsewhere within its breeding range other than localized extirpations due largely to habitat loss. Its absence from the Florida panhandle during the latter half of the twentieth century, for example, is attributed to the loss of bottomland timber and possibly the impacts of cowbird parasitism (Sherry et al. 2016).
*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.