118 



NORTH AMERICAN FAUNA 73 



(Washington County) until 27 December 1964 (Huber 1965). One observed 

 at St. Croix Falls, Polk County, on 9 March 1948 may have wintered locally 

 (Robbins 1948c). 



Habitat: Primarily a species of deciduous forest edge habitats. Important 

 among these are second-growth Northern Hardwood Forest, Deciduous 

 Clear Cuts, Old Field Community, and fencerows. Lowland Deciduous 

 Forest is occasionally used in the Western Upland and Black Spruce-Tam- 

 arack Bogs receive limited use in the Northern Highland. In residential 

 areas, ornamental shrubbery is used. 



Brown Thrasher (Toxostoma rufum) 



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



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

 fairly common in the Northern Highland. Spring migrants arrive in the 

 Western Upland 20-25 April (earUest— 4 April 1975, Washington County) 

 and reach the Northern Highland 25-30 April. Peak spring abundance 

 occurs 1-15 May. Fall migration begins 15-30 August; peak movements 

 occur 5-20 September and departure by 10 October. 



Nesting Season Distribution: Common nesting species in the Western 

 Upland and Central Plain, fairly common and more local in the Northern 

 Highland. Jackson (1943) reported this species as "not common" in north- 

 western Wisconsin in 1919 but almost 50 years later, Bernard (1967) consid- 

 ered brown thrashers "common" in Douglas County. Breeding Bird Survey 

 data (Table 5) suggest a gradual decrease in relative abundance moving 

 northward across the Valley. Major changes in abundance appear to occur 

 between the Central Plain and Northern Highland. Goddard (1972) reported 

 a breeding density of 6.4 pairs per 40 ha in the Kinnickinnic River VaUey, 

 Pierce County. 



Winter: There are three early winter records from Washington County: 

 20 December 1969, 29 December 1973, and 1 January 1975. One remained at 

 a Pierce County feeder through 11 January 1976 (Faanes and Goddard 

 1976). 



Habitat: Primarily a species of edge habitats. Important among these are 

 natural clearings in Southern Deciduous Forest, Old Field Community, 

 brushy fencerows, and Deciduous Clear Cuts. Recently logged oak forests 

 and grazed woodlots supporting an abundance of prickly ash and hawthorn 

 are frequently used in the Western Upland. 



FAMILY TURDIDAE: Thrushes, Solitaires, and Bluebirds 



American Robin [Turdus migratorius) 



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



Migration: Abundant migrant throughout the Valley. The first spring mi- 



