- Minnesota Breeding Bird Distribution
- Breeding Habitat
- Population Abundance
- Literature Cited
A regular breeding resident and migrant, the Chimney Swift was an uncommon species during the Minnesota Breeding Bird Atlas (MNBBA).
Distributed across the eastern half of the United States and southeastern Canada; populations occur west as far as the eastern Great Plains states and southeastern Saskatchewan. The species is most abundant in the north-central and southeastern states (Figure 1).
Assigned a Continental Concern Score of 13/20 and designated a Common Bird in Steep Decline by Partners in Flight; also designated a Species in Greatest Conservation Need by the Minnesota Department of Natural Resources.
A long-distance migrant that spends winters in northwestern South America.
Chimney or tree hollow.
Often referred to as a “flying cigar,” the Chimney Swift was considered by Roberts (1932) to be an abundant summer resident throughout much of Minnesota in the early 1900s. The one exception was the large, open stretches of prairie grasslands where trees and farmsteads were absent. The species could be found nesting in hollow trees in the old-growth forests and dilapidated cabins of northern Minnesota, and in chimneys and old farm buildings in southern Minnesota. Confirmed nesting records (nests with eggs or young) were available from 4 counties, including Hennepin and Sherburne Counties in the east-central region, and Cass and Cook Counties in the north.
The species distribution was little changed in the 40 years that followed. Green and Janssen (1975) wrote that the Chimney Swift occurred statewide but was most abundant near human habitations where chimneys and abandoned buildings provided suitable nest sites. It was still present, however, in “heavily forested areas, following its natural pattern of nesting in hollow trees.”
A few years later, Janssen (1987) specifically commented on the species’ rarity in the northwest region of the state. Despite its broad statewide distribution, nesting had been confirmed in only 5 counties since 1970: Aitkin, Clearwater, Hennepin, Morrison, and Rice. Hertzel and Janssen (1998) later identified 6 counties where nesting had been confirmed since 1970; Clearwater County was not included on their map, but Kandiyohi and Watonwan Counties were added.
As of 2014, biologists with the Minnesota Biological Survey had documented 168 breeding season locations for the species. Sparsely distributed throughout the state, records were most abundant in southern Minnesota but were again noticeably absent from the northwestern counties (Minnesota Department of Natural Resources 2016).
During the MNBBA, participants reported a total of 836 Chimney Swift records from 12.8% (612/4,774) of the surveyed atlas blocks and from 15.0% (351/2,337) of the priority blocks. Breeding evidence was gathered in 82 (1.7%) of the surveyed blocks (Figures 2 and 3; Table 1). Despite the relatively small number of records, the birds were observed in all but 1 of Minnesota’s counties (Isanti) and were confirmed breeding in 42 counties. Two blocks where nesting was confirmed each straddled 2 counties along the Minnesota River (Renville/Redwood and Nicollet/Brown). All but 5 counties were additions to Hertzel and Janssen’s 1998 list. As expected, the largest number of nesting records was from the Twin Cities metropolitan area. The land suitability model generated for the Chimney Swift emphasizes the species’ strong association with developed communities that provide nesting chimneys (Figure 4).
The major change in the nearly 100 years since Roberts wrote his account of the species in 1932 is the sparse but widespread occurrence of the species throughout the agricultural regions of the state, from southern Minnesota north through the Red River valley and aspen parklands. The small towns and cities that dot the landscape now provide more man-made opportunities for nesting.
The westward expansion observed in Minnesota has been witnessed elsewhere in the Great Plains. During South Dakota’s second atlas (2009–2012), for example, more Chimney Swifts were observed in small towns west of the Missouri River than during the first atlas (1988–1992) (Drilling et al. 2016). A small population even became established in southern California, far from the nearest nesting populations in eastern New Mexico and Colorado (Steeves et al. 2014). In contrast, both Ontario and Michigan witnessed an overall decline in observations between their first and second atlases, and a southern retraction of breeding populations (Cadman et al. 2007; Chartier et al. 2013).
*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.