BIRDS OF THE ST. CROIX RIVER VALLEY 



123 



Deciduous Clear Cuts, and openings in grazed woodlots. In the Northern 

 Highland and Central Plain, extensive use is made of Jack Pine Barrens. 

 This is evidenced by the high relative abundance of this species along the 

 Union BBS transect, Burnett County. Local populations, particularly in 

 agricultural areas, can be enhanced by the establishment and monitoring of 

 bluebird houses. Many 4-H Clubs and Future Farmers of America (FFA) 

 chapters have created "Bluebird Trails" that are very beneficial in providing 

 nesting sites. 



Townsend's Solitaire {Myadestes townsendi) 

 Status: Accidental. 



Records: One Townsend's sohtaire was observed at Hudson, St. Croix 

 County, from December 1942 to 10 January 1943 (Scott 1943a). Longley 

 (1973a) described the observation of a single bird in Chisago County on 

 27 April 1973. 



FAMILY SYLVIIDAE: Gnatcatchers and Kinglets 



Blue-gray Gnatcatcher (Polioptila caerulea) 

 Status: Regular migrant and nesting species. 



Migration: Uncommon and local migrant restricted primarily to the 

 Western Upland. Spring migrants arrive 1-5 May and are most conspicuous 

 after 15 May. Fall migration apparently begins in late July with dispersal of 

 family groups. This species is most common during the fall 1-15 August and 

 departure occurs by 25 August (latest— 6 September 1975, Washington 

 County). 



Nesting Season Distribution: Uncommon and local nesting species in the 

 Western Upland. Occasional summer records at St. Croix Falls, Polk 

 County, suggest possible nesting. The observations by Breckenridge (in 

 Roberts 1932) and Maurer (1970) of nests at Marine-on-St. Croix are prob- 

 ably the northernmost documented records in the Valley. Breckenridge re- 

 ported two adults, but no young, at Taylor's Falls, Chisago County, on 

 11 August 1938 (Erickson and Upson 1938). The area of greatest abundance 

 is restricted to the lower St. Croix River and its major tributaries from Still- 

 water, Washington County, south to its confluence with the Mississippi 

 River. 



The status of this species as a nesting bird in the Valley is apparently 

 changing. Robbins (1963) suggested that as of 1962 blue-gray gnatcatchers 

 "may not be counted on to be present every year" at Hudson, St. Croix 

 County. Since first observing nesting pairs along the Willow River at 

 Hudson in 1973, the number of pairs on one site has risen from 7 in 1973 to 

 17 in 1978. Expansion of this species along major St. Croix River tributaries 

 in Wisconsin is also evident. During 1976 and 1977, breeding pairs were lo- 

 cated along the Kinnickinnic River near Roberts, St. Croix County (Sec. 11, 

 T. 28 N., R. 18 W.), along the Willow River near Jewett, St. Croix County 



