54 



NORTH AMERICAN FAUNA 73 



pen-maple-basswood forest, intermixed with red pine. Additional summer 

 observations have been made in similar habitat and in brushy "edge" situa- 

 tions. This hawk is usually observed in oak-maple woodlots along the St. 

 Croix River during winter. Occasionally, an individual will frequent feeding 

 stations in residential areas. 



Cooper's Hawk (Accipiter cooperii) 



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

 has listed this species as threatened (Les 1979). Alteration of nesting habitat 

 resulting from intensive farming is a primary cause for their decline. 



Migration: Uncommon to rare migrant throughout the Valley. Spring migra- 

 tion begins in mid-March; birds are most frequently encountered 

 10-25 April. Nonsummering birds have departed by 15 May. Fall migration 

 begins in late August and continues through mid-October. Because of the 

 low number of birds observed during fall migration, no indication of peak 

 movements is provided. 



Nesting Season Distribution: Rare nesting species throughout the Valley. 

 Although this hawk is regularly observed during the summer, only two con- 

 firmed nesting records exist. On 13 June 1976 a nest containing two young, 

 and on 29 June 1976 a nest containing one young, were found 8 km west and 

 4.8 km east of Star Prairie, St. Croix County. Goddard (1972) reported one 

 pair during the breeding season in Pierce County and Jackson (1941) re- 

 ported a breeding season record (31 May 1919) for Burnett County. Nu- 

 merous other breeding season records exist, but data on eggs or young are 

 lacking. 



Winter: Rare winter resident in the Western Upland; casual to absent else- 

 where. 



Habitat: Both St. Croix County nests were in second-growth red oak wood- 

 lots, bordered by brushy fencerows. I have observed this species during the 

 breeding season in similar second-growth habitats and in mixed jack 

 pine-oak situations in Burnett and Pine counties. Wintering birds are regu- 

 larly observed occupying Lowland Deciduous Forest habitats during this 

 period. Like the sharp-shinned hawk, this species will occasionally frequent 

 bird feeding stations in residential areas during the winter. 



Red-tailed Hawk (Buteo jamaicensis) 



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



Migration: Common (locally abundant) migrant throughout the Valley. 

 During both seasons, large numbers of migrants can be observed associated 

 with the St. Croix River and at Crex Meadows WildUfe Area, Burnett 

 County. Spring migration begins in mid-February in the Western Upland 

 and Central Plain, reaching the Northern Highland about 1 March. Peak 

 spring movements occur 20 March to 15 April, and nonbreeders have de- 

 parted by 1 May. Fall migration begins in mid-August with dispersal of 



