near Back Bay and Mackay Island National Wildlife Refuges in Virginia 

 and North Carolina. 



Digestive tracts were collected in the vicinity of Back Bay, Virginia, 

 and Currituck Sound, North Carolina, during the 1968-69, 1969-70 and 

 1970-71 hunting seasons. Examinations of 170 waterfowl digestive tract 

 contents included 27 Canada geese, 74 dabbling ducks of six species, 

 38 diving ducks of four species and 31 coots. Analysis revealed that: 

 71.8 percent contained Eurasian milfoil, 84.7 percent held other foods, 

 13.5 percent had milfoil as the only food, 27.1 percent had other foods 

 but no milfoil, and 1.8 percent had no food. 



Quantitative analysis showed that the content of all digestive tracts 

 was 43.9 percent grit, 18.3 percent Eurasian milfoil, and 37.8 percent 

 other foods. When considering food only in the 170 tracts of 12 water- 

 fowl species, milfoil comprised approximately one-third of the volume. 

 Highest milfoil use was noted in scaups, followed in order by gadwalls, 

 widgeons, Canada geese, redheads, pintails, green-winged teals, ruddy 

 ducks, black ducks, coots, mallards and canvasbacks. Natural foods 

 led the "other foods" category and were headed by pondweeds, widgeon- 

 grass, southern naiad, wild celery plants and seeds, and seeds 

 from the family Cyperaceae. (A. A.) 



Keywords: Eurasian milfoil, waterfowl food, Virginia 



V-B-32 



Stotts, V.D., and D.E. Davis. 1960. The black duck in the Chesapeake 



Bay of Maryland: breeding behavior and biology. Chesapeake Science 



1:127-154. 



The breeding behavior and biology of black ducks. Anas rubripes , 

 were observed from 1953-1958 on the upper Eastern Shore of Chesapeake 

 Bay in Maryland. Ducks were trapped, banded, and marked during the 

 study in an essentially estuarine habitat, which was frost-free from 

 mid-April to early November, The general habitat adjoining the bay 

 consisted of cultivated fields, pine woods with dense underbrush, 

 extensive marshes in some areas, and duck blinds. 



Resident black ducks began to pair in the late summer, and the pairing 

 activity reached a peak in early April just before the height of the 

 breeding season. Few if any young were observed to pair in the early fall. 

 In the spring the male defended a territory for each clutch, generally 

 using some promontory along the shore. The male remained nearby while the 

 female built her nest, gradually deserting his mate during incubation. 

 Eventually the pairing bond disappeared, although some males probably 

 paired again with renesting hens. 



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