2 



NORTH AMERICAN FAUNA 69 



birds are on breeding territories, and especially during the court- 

 ship and preincubation periods when the pair are traveling to- 

 gether, they can often be approached to within 5 feet and kept under 

 observation at close range for many minutes. Several times during 

 its preincubation period, one paired bird fed within 2 feet of my 

 eyes as I lay prone on the ground. I found canebrakes to be the 

 best habitat for sustained observations : the visual conditions are 

 generally uniform, and the birds tend to stay away from the 

 densest part of the canebrake. 



Although the Swainson's Warbler is not as abundant as some 

 of the other southern warblers, in 1968 I knew of at least two 

 areas in which I could find 50 individuals in a single day. One of 

 these was the Great Dismal Swamp in southeastern Virginia ; the 

 other was the Ocmulgee River floodplain forest, 3 to 5 miles south- 

 east of Macon, Ga., where I first became acquainted with the 

 Swainson's Warbler (Meanley, 1945, p. 395-401). When stationed 

 at Camp Wheeler near Macon, 1944-46, I began making observa- 

 tions in the extensive riverbottom canebrakes, and I returned to 

 this area for further study in 1963 and each spring thereafter 

 through 1968. During these 24 years the habitat and number of 

 individuals remained virtually unchanged. 



When living at Alexandria, La., in 1956 and 1957, I made ob- 

 servations in Bayou Boeuf Swamp, at the edge of that central 

 Louisiana city. In Arkansas in 1967 I obtained information on 

 territorial and nesting behavior in the batture (land between the 

 levee and the river), between the mouth of Bayou Meto and 

 Pendleton Ferry, along the Arkansas River. Mountain habitats 

 near the City of Charleston and in Nicholas County, W. Va., were 

 visited during the spring of 1965 and 1966. In 1966 I began ob- 

 servations in the Great Dismal Swamp, a few miles south of 

 Norfolk, Va. This continues to be my main study area. 



METHODS 



Habitats in breeding territories were analyzed in several ways. 

 Plant species composition was determined by sampling ly4-acre 

 plots. In canebrake and scrub palmetto (Sabal minor) habitats, 

 the density and number of stems were determined by sampling 

 10-foot-square quadrats. 



The light-shading effect of the combined canopy, lower tree, 

 and shrub strata was determined in i4-acre plots of several 

 tracts. A 2-foot-diameter hoop divided into eight equal sections 

 was held directly overhead, and 20 random readings were made, 

 sighting upward. Readings were taken between 11:30 a.m. and 



