Table 145 
FOODS OF 9 RUDDY DUCKS FROM BRACKISH ESTUARINE BAYS OF THE 
CHESTER, PATUXENT, AND POTOMAC RIVERS? 
Seeds 33% _( 7-71) 
Southern Naiad 22 ( 2-61) 
Claspingleaf Pondweed 22 ( 2-61) 
Widgeongrass ll ¢ +=)9) 
Grassleaf Pondweed 11 ( +49) 
Animal Food 67% (29~93) 
Macoma phenax (Pelecypoda) 56 (21-87) 
Mya arenaria (Pelecypoda) 33 ( ?-71) 
Gammaridae 22 ( 2-61) 
Macoma balthioa (Pelecypoda) ll ( ++)9) 
Mulinia lateralis (Pelecypoda) 1 ( #-h9) 
Cyathura sp. (Isopoda) 11 ( %=)9) 
Xanthidae 11 ( +49) 
Crustacea (sp) nL ¢ +-h9) 

1 Collected November-March. Percentage ocourrence of foods that made up 5% 
or more of the volume in individual birds. Figures in parentheses show 95% 
confidence limits. 
203 
