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NORTH AMERICAN FAUNA 73 



scribed the eastward extension of this species' breeding range from the Red 

 River Valley to east-central Minnesota in the early 1900's. Additional evi- 

 dence of recent expansion into this region is provided by Jackson (1943) who 

 failed to record this bird in northwestern Wisconsin in 1919. 



Winter: Several CBC records of Brewer's blackbird exist for the Suburban 

 St. Paul count. These records include: 4 on 29 December 1962, 4 on 26 De- 

 cember 1964, and 11 on 30 December 1972. 



Habitat: Brewer's blackbirds primarily use fencerows, railroad rights-of- 

 way and Old Field habitats. Occasional breeding pairs are encountered in 

 Northern Sedge Meadow, open bog habitats, and in highway rights-of-way. 



Common Grackle (Quiscalus quiscula) 



Status: Regular migrant, nesting species, and winter resident. 



Migration: Abundant migrant in the Western Upland and Central Plain, 

 fairly common (locally common) in the Northern Highland. Spring migrants 

 arrive in the Western Upland 20-25 February, reaching the Northern High- 

 land by 30 March. Peak populations occur 20 March to 15 April. Fall migra- 

 tion begins in mid-July with dispersal from breeding areas. Large mixed 

 flocks of common grackles and red-winged blackbirds form in early August, 

 supplemented with Brewer's blackbirds in late August and rusty blackbirds 

 in late September. Peak fall populations occur 10 September to 10 October. 

 Departure from the Northern Highland occurs by 15 October and most birds 

 have departed from the Western Upland by 5 November but stragglers 

 remain to 30 November. 



Nesting Season Distribution: Common to locally abundant nesting species 

 in the Western Upland and Central Plain, uncommon to locally common in 

 the Northern Highland. This is one of the most rapidly increasing nesting 

 species in the Valley. Breeding Bird Survey data (Table 7) show a gradual 

 decrease in relative abundance northward from the heavily farmed regions 

 of the Western Upland. In 1919, Jackson (1943) reported that common 

 grackles were "never particularly plentiful, except when they gathered in 

 flocks." The current abundance of this species and the expansion of its 

 breeding range has been fairly recent and may be associated with an ex- 

 panding human population or changes in agricultural practices. 



Winter: Common grackles occasionally overwinter each year in the Western 

 Upland. Individual birds elsewhere may be wintering or late migrants. 



Habitat: Common grackles are fairly opportunistic in their selection of 

 nesting habitats and have been recorded in nearly every habitat type. High- 

 est breeding densities are usually associated with Pine Plantations, decid- 

 uous woodlots, or ornamental conifer plantings. The increased planting of 

 coniferous trees has enhanced common grackle nesting populations and may 

 be a factor in their expanding and increasing populations. 



Brown-headed Cowbird {Molothrus ater) 



Status: Regular migrant and nesting species, casual early winter resident. 



