Table 104 
FOODS OF 17 RING-NECKED DUCKS FROM FRESH ESTUARINE BAYS 
OF THE POTOMAC RIVER} 

Leaves, Stems and Rootstalks of 
Submerged Aquatic Plants 82% (56-97) 
Pondweed 53 (27-78) 
Naiad 2h ( 6-50) 
Wildcelery 6 ( 29) 
Sago Pondweed 6 ( #29) 
Grassleaf Pondweed & ( 4-29) 
Animal Food _uT% (22-73) 
Oxytrema virginica (Gastropoda) 35) (1462) 
Trichoptera larvae 6 ( +29) 

1 Collected November 10-March 23. Percentage occurrence of foods that made up 
5% or more of the volume in individual birds Figures in parentheses show 95% 
confidence limits. 
164 
