brackish ditch, but there was none in the shallow marsh waters. 

 Gradients were more pronounced in canals, but the gradients were 

 variable. 



The source of marsh water was almost entirely from rainfall. Water 

 loss was normally through surface evaporation and transpiration. Water 

 depths were greatest inland and decreased toward the Gulf, Winds 

 profoundly affected water levels, but tidal influence was negligible. 

 Water levels were lowest in early fall. The pH of marsh waters was 

 slightly alkaline, and marsh soils were nearly neutral. 



A map of the marsh vegetation was compiled and fresh, brackish, 

 and salt-marsh zones were defined. Frequency distributions of marsh 

 plants correlated well with soil salinities. Soils of the salt-marsh 

 were azonal ; brackish and fresh-marsh soils were intrazonal. Changes 

 in marsh plant associations reflect adjustments to soil development, 

 salinity, and water levels. 



Mallards comprised 54 percent of the wintering duck population, 

 and blue geese constituted 92 percent of the wintering geese. The 

 majority of the waterfowl population was in the area from late 

 October to the following April. Waterfowl composition was different 

 in various types of marshes. 



Marsh plant utilization was determined by analysis of 1,251 gizzards 

 from 17 species of wintering waterfowl. Differences occurred in items 

 taken by ducks in different types of marshes. Forty-nine plants 

 were identified from remains of food materials in the gizzards. 

 Seeds of Cladium , Scirpu s and Eleocharis were most frequently taken. 

 It was concluded that utilization of food items depends primarily 

 on their relative availability. (A. A.) 



Keywords: coastal marsh, ecology, marsh plants, waterfowl, Louisiana 



V-B-20 



Chamberlain, E.B. 1959. Gulf coast marsh vegetation as food of wintering 

 waterfowl. Journal of Wildlife Management 23:95-102. 



The gizzard contents of seventeen species of ducks and geese were 

 studied. Forty-nine plant species were identified. Seeds of Cladium , 

 Scirpus , and Eleocharis were found to constitute important food 

 sources. (J .FT] 



Keywords: coastal marshes, marsh plants, waterfowl foods, U.S. Gulf coast 



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