migrate earlier when less shot is available. Ring-necked ducks, canvasbacks, and redheads, which show 
a high proportion of gizzards containing ingested lead, usually dig for seeds and tubers of aquatic plants, 
wt 
. eee oe 
sibiexelavezane @lelainietevaieialalaieta'etu\ecs/ rs! e la lelecOlb aus sik eieCe ere eLb ie ClO Si8 68:80:08.8 8 ee cel esel8 81 ere 6 0.8 ele 
N O @ oO Tt aN) 
SwlOadS HOVE NI SL3113d ONINIVLNOD SGYVZZID 3O LIN39 Yad 
d States in autumn and 
Fig. 11. -- Occurrence of commercial shot pellets in the gizzards of 18,454 ducks of various species. 
The gizzards were collected in recent years from many parts of the Unite 
early winter. 
Sia 
