BIRDS OF THE ST. CROIX RIVER VALLEY 



103 



Douglas counties with inferred nesting elsewhere. Breeding Bird Survey 

 data (Table 3) indicate that a fairly uniform breeding population occurs in 

 the Western Upland and Central Plain. Relative abundance increases mark- 

 edly north of that zone. Goddard (1972) found this species to be the sixth 

 most abundant breeding bird along the Kinnickinnic River in Pierce County. 

 The mean breeding density in that area was 27.4 pairs per 40 ha. 



Habitat: The eastern wood pewee is characteristic of mature deciduous 

 forest. In the Western Upland, breeding pairs are generally associated with 

 mature Lowland Deciduous Forest and occasionally with mature Southern 

 Deciduous Forest. Central Plain and Northern Highland populations are 

 apparently most numerous in mature Northern Hardwood Forest. 



Olive-sided Flycatcher [Nuttallornis horealis) 

 Status: Regular migrant and nesting species. 



Migration: The ohve-sided flycatcher is among the latest arriving songbirds. 

 Average date of spring arrivals in the Western Upland is 16 May and arri- 

 vals in the Northern Highland are during 20-25 May. Dates of peak abun- 

 dance are not provided, primarily because this bird migrates singly or in 

 small groups. Consequently, very few individuals are recorded daily during 

 periods when they would be expected to be numerous. Migrants have usually 

 departed nonbreeding areas by 1 June (latest— 11 June 1974, Pierce 

 County). Fall migrants arrive in the Western Upland during early August 

 and become most conspicuous 20-30 August. Departure from northern 

 nesting areas occurs about 5 September and departure elsewhere by 20 Sep- 

 tember. 



Nesting Season Distribution: The only confirmed evidence of nesting is pro- 

 vided by Green and Janssen (1975) who Usted a nest record from Sturgeon 

 Lake, Pine County. Considerable inferred breeding evidence exists for north- 

 ern Burnett and southern Douglas counties where this bird is an uncommon 

 and local summer resident. Although nests have not been observed, exten- 

 sive stands of black spruce-tamarack habitat along the St. Croix River in 

 Burnett, Douglas, and Pine counties usually support breeding season 

 adults. 



Habitat: Ohve-sided flycatchers are characteristic of boreal forest habitat 

 during the nesting season. Extensive stands of Lowland Coniferous Forest, 

 combined with an interspersion of open areas of sphagnum moss provide 

 ideal breeding habitat. Also frequently used are white cedar swamps. One 

 factor that characterizes ohve-sided flycatcher habitat is the presence of 

 dead snags that are used for feeding and singing perches. 



FAMILY ALAUDIDAE: Larks 



Horned Lark {Eremophila alpestris) 



Status: Regular migrant and nesting species, casual winter resident. 



