Distribution 



BREEDING RANGE 



The Swainson's Warbler spends nearly 6 months of the year in 

 the United States (fig. 8). During this period the bird is primarily 

 associated with the river floodplain forests and swamps of the 

 South Atlantic and Gulf Coastal Plains, and with the rich moist 

 woods of the Mixed Mesophytic forest (see Braun, 1950, p. 39-49) 

 of the Southern Appalachians. The mountain habitats are in the 

 hemlock-rhododendron (Tsuga canadensis-Rhododendron maxi- 

 mum) association and the cove hardwoods forest. Apparently the 

 Piedmont Province is generally unsuitable for occupation by this 

 species. While there are scattered records of its occurrence in the 

 Piedmont Province during the breeding season, there appear to be 

 no breeding concentrations in this in-between area. The swamps 

 and floodplain forests of the Coastal Plain, and sections of the 

 Mixed Mesophytic forest where this species occurs in the moun- 

 tains, are more humid than most of the forests of the Piedmont. 



During the summer the climatic features of the two major 

 physiographic regions occupied by the Swainson's Warbler are 

 somewhat similar. Blair (1942, p. 130, 132) has classified the 

 climate of the South Atlantic and Gulf Coastal Plains as Humid 

 Subtropical type, and the climate of the Southern Appalachians 

 as Humid Continental type (warm long summer subtype). The 

 Humid Subtropical climatic type has a moderate-to-heavy rainfall 

 at all seasons, usually with a maximum in summer ; 9 to 12 months 

 with mean temperature above 50° F. ; and a growing season of 

 220 days or more. The Humid Continental type (warm long sum- 

 mer subtype) has a rainfall between 20 and 40 inches with a 

 summer maximum ; 6 to 9 months with mean temperature above 

 50° F. ; and a growing season of 140 to 220 days. 



Atlantic Coastal Plain 



Along the Atlantic Coastal Plain the Swainson's Warbler occurs 

 from extreme southern Delaware to southeastern Virginia and 

 southward and inland as far as the fall line to about Jacksonville 

 and the Suwannee River in Florida. 



The northern limit on the Atlantic coast is the Pocomoke River 

 Swamp in Sussex County, Del., and Worcester County, Md. The 

 Pocomoke Swamp lies about 10 miles inland from the Atlantic 



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