BIRDS OF THE ST. CROIX RIVER VALLEY 



145 



migrants arrive in the Northern Highland about 5 August, reaching the 

 Western Upland 20-25 August (earliest— 12 August 1962, St. Croix 

 County). Peak fall migration occurs 25 August to 10 September and de- 

 parture by 30 September. 



Nesting Season Distribution: Rare and local breeding species, occurring pri- 

 marily in the Northern Highland. Most observations of nesting season 

 northern waterthrushes have been in habitats along and adjacent to the St. 

 Croix River in Douglas, Burnett, and Pine counties. Breeding Bird Survey 

 data show the low breeding density of this species in the Valley. Goddard 

 (1972) reported a northern waterthrush during the breeding season along the 

 Kinnickinnic River, Pierce County, in June 1971. If correct, that record 

 would extend the probable breeding range of this species at least 160 km 

 south. The lack of proper habitat, plus the population of Louisiana water- 

 thrush along the river, render that record suspect. 



Habitat: This species uses a narrow range of wet habitats in the Northern 

 Highland. Primary breeding habitat includes Lowland Coniferous Forest, 

 Alder Thicket, and Northern Sedge Meadow that is becoming invaded with 

 various shrubs including smooth alder and gray dogwood. During migration 

 in the Western Upland and Central Plain, Lowland Deciduous Forest, 

 Northern Hardwood Forest, and Deciduous Clear Cuts are used extensively, 

 as are shorelines of lakes and streams. 



Louisiana Waterthrush {Seiurus motacilla) 

 Status: Regular migrant and nesting species. 



Migration: Rare spring migrant in the Western Upland and Central Plain. 

 Records in the Central Plain are restricted to areas south of St. Croix Falls 

 and Taylor's Falls. No well-defined pattern of spring migration can be estab- 

 lished. Most birds observed appear to be on estabUshed breeding territories. 

 Most spring individuals occur 10-30 May (earliest— 27 April 1964 [Soulen 

 1965], 2 May 1948, and 3 May 1966; Washington County). Fall migration is 

 early and diffuse (latest— 23 August 1974, Chisago County; 11 September 

 1972, St. Croix County). 



Nesting Season Distribution: Rare and local nesting species of the Western 

 Upland and Central Plain. Confirmed breeding records exist for Chisago 

 (Green and Janssen 1975), Washington, and St. Croix counties. Breeding 

 season birds have also been recorded in Pierce and Polk counties; however, 

 nest records are lacking. 



Probably the best-known breeding area in the Valley for Louisiana water- 

 thrush is along Lawrence Creek near Franconia, Chisago County. Longley 

 (19736) described the first known breeding record of this bird at that loca- 

 tion, when a nest containing two young cowbirds, one young Louisiana 

 waterthrush, and one addled egg was found near Franconia on 9 June 1973. 

 In June 1968 Longley (19736) recorded six singing males at this same local- 

 ity. One Louisiana waterthrush was also recorded at that location in 

 1974-76 and a nest was found in 1975. 



Another well-known nesting area is along the lower Willow River near the 



