Winter and Offshore Black Ducks are usually found in salt-water habitats 

 in winter. Along the Middle Atlantic coast (where most winter) they are found 

 primarily in brackish marshes near bays and estuaries. Other habitats used in 

 this area include a variety of freshwater areas as well as old ricefields. 

 Along the coast to the north, the Black Duck is more strictly marine and feeds 

 on tidal flats, salt meadows, and in floating beds of aquatic plants. 



FOOD AND FEEDING BEHAVIOR 



Black Ducks feed primarily by "tipping-up" in shallow waters, although on 

 occasion they also graze (Johnsgard 1975). They may dive when foraging in deep- 

 er water (Bourget and Chapdelaine 1975) and have been known to dive as deep as 

 10 ft (3.0 m) (Palmer 1976a). 



The diet of the Black Duck varies so much from habitat to habitat that Pal- 

 mer (1976a) remarked that tables of composite diet were of limited use. He 

 noted that one or two staples usually comprise most of the diet and that plant 

 foods are consumed more in freshwater and brackish habitats; animal foods are 

 more important in maritime habitats. 



Detailed information on foods eaten at specific localities within the south- 

 east is summarized by state below. For an extensive listing of foods eaten in 

 other parts of the range see Palmer (1976a). 



North Carolina Twenty-two wintering Black Ducks collected on Curri- 

 tuck Sound ate a wider variety of foods than the other species of ducks examined 

 (Quay and Critcher 1965). Virtually all the food (99.8% by volume) was of vege- 

 table origin. The most important items in the diet were the seeds and vegeta- 

 tive parts of smartweed ( Polygonum sp. - 35.8%), the seeds of bulrush ( Scirpus 

 sp. - 13.0%), and the seeds and vegetative parts of widgeongrass ( Ruppia mari- 

 t ima - 12.3%). Other identified foods making up more than 3% of the diet were 

 the vegetative parts of southern naiad ( Naias guadalupensis - 6.7%), wax-myrtle 

 ( Myrica - 4.1%), and spikerush ( Eleocharis - 3.0%). 



South Carolina Conrad (1965) reported the winter food habits of 23 

 Black Ducks collected in the vicinity of the lower Pee Dee and Waccamaw rivers 

 near the coast in northeastern South Carolina. These ducks had consumed 97.6% 

 vegetable food and 2.4% animal food; a third of the diet (by volume) consisted 

 of swamp smartweed ( Polygonum hydropiperoides ) . Other plant foods significant 

 in the diet were aneileraa ( Aneilema keisak - 16.7%), squarestem spikerush (Eleo- 

 charis quadrangulata - 14.4%), softstera bulrush ( Scirpus validus - 9.1%), the 

 berries of arrow alum ( Peltandra virginica - 6.2%), and wild rice ( Zizania 

 aquatica - 5.8%). The only animal food consumed to any extent was small fiddler 

 crabs (2.0%). Conrad commented that the Black Duck ate more wild rice and more 

 animal food than any of the other ducks studied. 



McGilvrey (1966) reported foods eaten in November and December by 32 Black 

 Ducks from Lake Marion, the most important inland wintering area for waterfowl 

 in South Carolina. The diet was again largely vegetable (97.2%), with corn 

 ( Zea mays - 13.0%), seeds of sweet gum ( Liquidambar styracif lua - 11.1%), and 

 swamp smartweed (8.1%) consumed in the largest amounts. Other items making up 



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