56 



NORTH AMERICAN FAUNA 73 



Winter: Rare and local winter resident of Lowland Deciduous Forests in the 

 Western Upland, casual elsewhere. 



Habitat: Primarily a species of medium-aged to mature Lowland Deciduous 

 Forest. Rarely encountered away from this habitat type during the breeding 

 season. S. D. Robbins and I recorded one red-shouldered hawk, apparently 

 on territory, in mature black spruce habitat near Range, Polk County, on 

 16 March 1975. 



Broad-winged Hawk (Buteo platypterus) 

 Status: Regular migrant and nesting species. 



Migration: Fairly common spring and common fall migrant throughout the 

 Valley. During peak fall migration, broad-winged hawks are occasionally 

 abundant at the Crex Meadows WildUfe Area, Burnett County. Spring 

 migrants arrive in the Western Upland and Central Plain in early April (ear- 

 Hest— 26 March 1975, St. Croix County; 24 March 1968, Chisago County). 

 Migrants arrive in the Northern Highland 5-10 April (earliest— 21 March 

 1956, Burnett County). Peak spring migration occurs 15 April to 1 May, and 

 nonbreeders depart by 20 May. 



Fall migration begins in late August, with dispersal from nesting areas 

 and formation of loose flocks. Peak fail migration occurs 10-25 September, 

 when 400 to 500 individuals can be observed on good fhght days. Movement 

 is very rapid, and departure from the region occurs by 10 October. 



Nesting Season Distribution: Common nesting species throughout the 

 Northern Highland and northern tier of the Central Plain. Fairly common in 

 the remainder of the Central Plain. Rare and local in the Western Upland. 

 Nest records exist for all counties of the Valley except Pierce. In the North- 

 ern Highland, the broad-winged hawk must be considered the most abun- 

 dant and conspicuous nesting raptor. Roberts (1932), quoting Surber (1919), 

 stated that along the St. Croix River in Pine County, the broad-winged hawk 

 was "the commonest hawk" in the region. 



Habitat: Broad-winged hawks use a variety of coniferous and deciduous 

 forest types for nesting. Regularly used habitats in the Northern Highland 

 and Central Plain include Northern Upland Deciduous Forest, Upland Conif- 

 erous Forest, and mixed deciduous-coniferous forest. Jack Pine Barren and 

 jack pine-oak habitats are also occupied, but to a lesser extent. Nesting 

 broad-winged hawks have been found occupying Southern Deciduous Forest 

 and Lowland Deciduous Forest in the Western Upland. 



Swainson's Hawk {Buteo swainsoni) 



Status: Casual migrant throughout the region, regular in St. Croix County. 

 Several recent summer records. 



Migration: Rare and local migrant with records from all regions. Spring 

 migration dates range from 3 April 1965 (Burnett County) to 20 May 1967 

 (Pine County). Most records occur between 20 April and 15 May. Fall migra- 



