32 



NORTH AMERICAN FAUNA 69 



The number of cane poles in 10 quadrats varied from 18 to 75 per 10-foot- 

 square quadrat. There were about 20,000 cane poles per acre in my sample 

 area which was virtually devoid of other plants, except for a scattering of 

 large trees. 



Of 91 territorial males that I observed in seven nesting seasons 

 near Macon, 87 had territories (averaging about 1 acre each) in 

 patches of cane growing beneath the floodplain forest canopy. 

 The floodplain forest in this area was composed mainly of the 

 following trees (in descending order of abundance) : hackberry 

 (Celtis occidentalis) , boxelder (Acer Negundo), red ash (Frax- 

 inus pennsylvanica) , American elm (Ulmus americana) , sweet- 

 gum, water oak, swamp chestnut oak (Quercus Michauxii), silver 

 maple (Acer saccharinum) , and mulberry (Morits sp.). The 

 understory was mostly cane, but in openings included blackberry 

 (Ruhus sp.), swamp privet (Forestiera acuminata), or saplings 

 of the above-mentioned trees. The coverage of the combined strata 

 of upper canopy, lower trees, and understory was about 85 per- 

 cent. Twelve exposure meter readings, made at feeding sites of 

 four Swainson's Warblers, ranged from 100 to 225 footcandles. 



The ground in areas occupied by the warblers is dry except 

 during periodic flooding. During three nesting seasons when I 

 entered the floodplain forest the water was 6 feet deep in some 

 canebrake areas where I usually conducted studies. Sometimes 

 these floodwaters recede in less than a week, and the habitat re- 

 turns to normal. Such flooding sometimes occurs during the height 

 of the nesting season, with a devastating effect on nesting success, 

 since the average nest height is about 4 feet, and some nests are 

 only a foot and a half from the ground. 



A 7-acre tract of cane about 3.5 miles southeast of Macon had 

 three territorial males in 1944, five in 1945, four in 1963, and one 

 in 1968. There was gradual reduction in the amount of cane in 

 this tract over the 24-year period. In 1968, I counted 19 territorial 

 males along a 2-mile transect about 5.5 miles southeast of Macon 

 in an area known as Bond Swamp. 



The following notes that I made on breeding bird associates 

 appeared in the Living Bird, Fifth Annual, (Meanley 1966, p. 

 158-159) : 



In the Ocmulgee River floodplain forest near Macon, the nesting species 

 in closest association with the Swainson's Warbler were the Cardinal (Rich- 

 mondena cardinalis) , Hooded Warbler (Wilsonia citrina), and the White- 

 eyed Vireo (Vireo griseus). All three nested in or on the edge of canebrakes 

 as well as in other plant associations. The Cardinal fed mainly along the 

 edge of cane thickets and in forest openings such as logging roads. The 

 Hooded Warbler, which fed regularly from 2 to 30 feet above the ground, 



