40 



NORTH AMERICAN FAUNA 69 



Figure 19.~Umbrella magnolia, prominent understory tree in habitat of the 

 Swainson's Warbler near Charleston, W. Va. 



ravine beside Donley Branch and climbs several hundred feet 

 higher, Swainson's Warblers can be heard singing on both forested 

 slopes, often two or three hundred feet up from Donley Branch. 

 I counted seven singing males as I walked a mile up the hollow 

 on May 15, 1965. There are probably fewer birds in the hollow 

 now than at the time Sims and DeGarmo made their study, 

 since the lower, moister slopes are now occupied by suburban 

 residences. 



The Donley Hollow habitat is like a Costal Plain floodplain 

 forest on the side of a hill. In these moist hollows or mountain 

 ravines the dominant canopy species of the mature cove hard- 

 woods forest is tulip poplar. The diameters at breast height of the 

 four largest tulip poplars in one Swainson's Warbler breeding 

 territory in 1965 were 25, 30, 33, and 36 inches. Other trees of 

 the upper canopy layer were mainly beech (Fagus grandifolia) , 

 buckeye (Aesculus sp.), black oak (Quercus velutina), red maple, 

 and sweetgum. Lower trees were umbrella magnolia (Magnolia 

 tripetala) (fig. 19), dogwood (Cornus florida), and paw-paw. The 

 undergrowth was mainly spicebush (Lindera benzoin), with oc- 

 casional thickets of greenbrier and Japanese honeysuckle 

 (Lonicera japonica). Thinly distributed herbaceous plants of the 



