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NORTH AMERICAN FAUNA 73 



Winter: Regular winter resident in the Western Upland, casual elsewhere. 

 Wintering red-winged blackbirds are usually associated with Lowland 

 Deciduous Forest, Shrub Carr, Alder Thicket, natural basin wetlands, farm- 

 steads, and feedlots. 



Habitat: Red-winged blackbirds use a variety of wetland and upland sites 

 for nesting. Wetlands include sedge meadows, seasonally, semipermanently, 

 and permanently flooded wetlands dominated by cattail, river bulrush, hard- 

 stem bulrush, softstem bulrush, and phragmites. Alder Thicket, Shrub 

 Carr, northern Forest Bordered Wetlands, and Black Spruce-Tamarack 

 Bogs are also important. Upland nesting sites include agricultural fields, 

 Old Field Community, Hayland, Managed Grasslands, and to a lesser extent 

 Northern Hardwood Forest, Southern Deciduous Forest, and Lowland 

 Deciduous Forest. This species is among the most widespread and adaptable 

 breeding birds in the Valley. 



Orchard Oriole {Icterus spurius) 

 Status: Casual migrant and nesting species. 



Migration: Rare migrant in Pierce, St. Croix, and Washington counties; acci- 

 dental elsewhere. Migrants arrive 15-20 May, remaining in this region until 

 mid- August. There are two spring records for Polk County: 20 May 1949 

 and 20 May 1976. 



Nesting Season Distribution: Several nesting season records exist in the 

 Western Upland; however, only one confirmed nesting record exists. A nest 

 with eggs was found in Washington County on 15 July 1953 (Herz 1954). S. 

 Sprunt found a singing male near Gordon, Douglas County, on 6 July 1956 

 (Lound and Lound 19566). Recently, nesting season adults have been regu- 

 larly observed along the lower Willow River in St. Croix County. Although 

 nest records have not been obtained here, strong evidence of nesting exists. 



Habitat: Breeding season orchard orioles are typically associated with open 

 areas in mature Lowland Deciduous Forest. 



Northern Oriole (Icterus galbula) 

 Status: Regular migrant and nesting species. 



Migration: Common migrant throughout the Valley, locally abundant adja- 

 cent to the St. Croix River in St. Croix, Pierce, and Washington counties. 

 Spring migrants arrive in the Western Upland 1-5 May and peak popu- 

 lations occur 15-20 May. Spring migrants arrive in the Northern Highland 

 by 10 May (earUest— 26 April 1957, Burnett County; Lound and Lound 

 1957c), reaching peak populations 20-25 May. Fall migration begins in late 

 July. Peak movement in the Northern Highland occurs 5-20 August and de- 

 parture is by 10 September. Peak fall migration in the Western Upland 

 occurs 15-30 August and departure is by 15 September (latest— 1 December 

 1971, Washington County). 



Nesting Season Distribution: Common nesting species in the Western 



