BIRDS OF THE ST. CROIX RIVER VALLEY 



169 



occurs 15-30 September and departure by 15 October (latest— 25 October 

 1967, St. Croix County). 



Nesting Season Distribution: Fairly common nesting species in the Western 

 Upland and Central Plain, uncommon and more localized in the Northern 

 Highland. Breeding Bird Survey data (Table 8) suggest that in the W^estern 

 Upland and Central Plain the savannah sparrow is among the three most 

 common nesting sparrows. However, this abundance decreases rapidly 

 moving northward into the heavily forested Northern Highland. 



Habitat: Characteristic breeding species of various grassland communities. 

 Important among these are retired cropland. Old Field Community, high- 

 way rights-of-way, Managed Grasslands maintained for duck production, 

 and lightly to moderately grazed tame pasture that is predominantly 

 timothy or Kentucky bluegrass. Also important, although to a lesser degree, 

 are alfalfa and oat fields. In Northern regions, savannah sparrows make 

 extensive use of wet meadow habitats, primarily Northern Sedge Meadow. 



Grasshopper Sparrow {Ammodramus savannarum) 

 Status: Regular migrant and nesting species. 



Migration: Fairly common migrant throughout the Western Upland and 

 Central Plain, uncommon to rare and locaUzed in the Northern Highland. 

 Spring migrants arrive in the Western Upland 25 April to 1 May and the 

 Northern Highland about 5 May. Peak spring migration is difficult to deter- 

 mine, although it is widely distributed 5-15 May. During the fall, grass- 

 hopper sparrows are rarely encountered after the song period ceases about 

 1 August, but they are probably present until mid- September. 



Nesting Season Distribution: Fairly common nesting species in the Western 

 Upland and Central Plain, rare and local in the Northern Highland. Jackson 

 (1943) did not record this sparrow during the 1919 nesting season in north- 

 western Wisconsin. Breeding Bird Survey data (Table 8) suggest that the 

 breeding populations in the Western Upland and Central Plain occur in 

 nearly equal abundance, becoming much smaller in the Northern Highland. 



Habitat: Primarily a nesting species of various grassland communities. Im- 

 portant among these are retired croplands, unmowed highway rights-of- 

 way. Managed Grasslands maintained for duck production, and Hghtly 

 grazed tame pasture that is predominantly Kentucky bluegrass or timothy. 

 Also important, although to lesser degrees, are alfalfa and oat fields. Occa- 

 sional use is made of the drier portions of Shrub Carr wetlands and Northern 

 Sedge Meadow. 



Baird's Sparrow (Ammodramus hairdii) 

 Status: Hypothetical, two records. 



Records: One bird was observed at Crex Meadows, Burnett County, on 

 12 May 1957 (Stone 1957). Goddard (1976) reported a single bird, also at 

 Crex Meadows, on 2 May 1975. 



