144 



NORTH AMERICAN FAUNA 73 



migrant. Fall migrants arrive in the Northern Highland 20-25 August and 

 the Central Plain 25 August to 5 September. Peak fall migration occurs 

 10-25 September and birds depart by 10 October (latest— 25 October 1968, 

 Chisago County). 



Nesting Season Distribution: This species probably nests in Douglas County 

 (S. D. Robbins, personal communication). On 27 June 1966, Robbins heard a 

 singing male palm warbler in a bog in Sec. 35, T. 43 N., R. 12 W. On 26 June 

 1974 a male was heard in Sec. 23, T. 43 N., R. 12 W. On the same date an- 

 other male palm warbler was recorded in a large open bog 6.4 km north of 

 Moose Junction (T. 44 N., R. 14 W.). 



Habitat: In the Western Upland and Central Plain, palm warblers occupy 

 medium-aged deciduous forest extensively. Alder Thicket and Shrub Carr 

 are also important. In the Northern Highland, extensive use is made of Low- 

 land Coniferous Forest, Black Spruce-Tamarack Bogs, and sedge meadow. 

 Nesting season records are of birds in open Black Spruce- Tamarack Bogs. 



Ovenbird (Seiurus aurocapillus) 



Status: Regular migrant and nesting species. 



Migration: Common migrant throughout the Valley. Spring migrants arrive 

 in the Western Upland about 1 May and the Northern Highland 5-10 May. 

 Peak spring migration occurs 10-20 May. Departure from nonbreeding 

 areas of the Western Upland occurs by 25 May. Peak fall migration is 1 Sep- 

 tember (Northern Highland) to 10 September (Western Upland) and de- 

 parture is by 1 October. 



Nesting Season Distribution: Common to locally abundant breeding bird in 

 the Northern Highland and Central Plain. Uncommon and local in the West- 

 ern Upland. Breeding Bird Survey data (Table 6) indicate that this warbler 

 occurs in greatest numbers in the Northern Highland and Central Plain. 

 Jackson (1943) referred to the ovenbird as the characteristic and often domi- 

 nant breeding bird in heavier deciduous forest (= mature Northern Hard- 

 wood). Goddard (1972) reported the ovenbird was the most abundant breed- 

 ing warbler in the Lower Kinnickinnic River Valley, Pierce County. 



Habitat: Characteristic nesting species of mature Northern Hardwood 

 Forest, where the predominant tree species include sugar maple, basswood, 

 trembUng aspen, and white birch. In the Western Upland, breeding oven- 

 birds are associated with red oak-Hill's oak forest. Remnant stands of 

 mixed red pine and white pine are regularly used in the northern regions. 



Northern Waterthrush (Seiurus noveboracensis) 

 Status: Regular migrant and nesting species. 



Migration: Fairly common migrant in the Western Upland and Central 

 Plain, locally common in the Northern Highland. Spring migrants arrive 

 1-5 May, reaching the Northern Highland 5-10 May. Peak migration occurs 

 10-20 May and departure from nonbreeding areas is by 30 May. Fall 



