BIRDS OF THE ST. CROIX RIVER VALLEY 



47 



(Douglas County). 



Habitat: The Polk County broods were observed on semipermanently 

 flooded wetlands. Dominant vegetation included cattail, burreed, and coon- 

 tail. Most summering pairs are observed on small semipermanent wetlands. 



Common Goldeneye {Bucephala clangula) 



Status: Regular migrant and winter resident, one summer record. 



Migration: Common migrant throughout the Valley, most numerous along 

 the St. Croix River and on large lakes of the Northern Highland. Fall 

 migrants arrive in the Northern Highland 20 September to 1 October and 

 reach the Western Upland 10-20 October. Peak fall common goldeneye 

 populations occur 10-30 November. 



Spring migrants reach peak abundance 10 March to 1 April and most have 

 departed by 1 May (latest— 30 May 1967, Burnett County). Movement of 

 spring migrants is similar to fall; most birds use rivers and large lakes. 

 Goddard (1975) found that common goldeneyes on prairie wetlands made up 

 <1% of the total spring waterfowl population; his 4-year observations 

 totaled 707 individuals. On the St. Croix River < 16 km from Goddard's 

 study area, daily totals in excess of 100 individuals were recorded on 

 8 March 1975, 11 March 1977, and 9 April 1978. Yearly totals in excess of 

 2,000 individuals along the St. Croix River were regularly recorded from 

 1972 to 1978. 



Winter: Common winter resident wherever open water is present. Primary 

 wintering populations occur at the confluence of the St. Croix and Missis- 

 sippi Rivers at Prescott, Wisconsin (150 to 200 individuals); below the Alan 

 S. King generating plant at Bayport (Washington County); near Hudson 

 (425 on 1974 Afton CBC and 360 on 1975 Afton CBC); and below the electric 

 generating dam at St. Croix Falls-Taylors Falls (50 to 100 individuals). 



Summer: S. D. Robbins observed a lone male throughout the summer of 

 1967 in St. Croix County. 



Habitat: Large open stretches of rivers that apparently support healthy 

 populations of fishes and invertebrates. During migration, common golden- 

 eyes are typically associated with large ( > 20 ha) permanent lakes. 



Barrow's Goldeneye {Bucephala islandica) 

 Status: Accidental, two records. 



Records: Faanes and Goddard (1976) cited one observation from East Twin 

 Lake, St. Croix County, on 8 May 1975. M. R. Olson observed one male 

 along Trout Brook Road near Hudson, St. Croix County, on 1 January 1977. 

 The bird was observed again on 2 January 1977 on the St. Croix River. 



Bufflehead (Bucephala albeola) 



Status: Regular migrant, one summer and one winter record. 



