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Typical waterfowl habitat in the Great Slave Lake country of Northwest Territory where Bureau and Canadian 

 Wildlife Service biologists determine duck production. Greater scaup nest nearly under log in the foreground. 

 (Photo by H. W. Murdy) 



water surface covered with emergent vegetation: 

 also preferred were ponds in pastures and those 

 containing hard-stemmed bulrush. Nesting hens 

 preferred ponds an acre or less in size, and nesting 

 success was highest on ponds less than half an 

 acre in size. The highest nesting success and the 

 vegetative preference of nesting birds was in cat- 

 tails. Brood use was greatest on the more per- 

 manent ponds, between half an acre and 10 acres 

 in size, with little emergent vegetation and with 

 water depth of 24 inches or more. 



Canvasback production was high in the Min- 

 nedosa locality in 1964; however, this area was an 

 "island" of optimum habitat, whereas much of the 

 Canadian Prairie had not recovered from the 

 drought. 



Waterfowl nesting in the southwest Lake Erie 

 region. — Random sampling of nearly 14,420 acres 

 of alfalfa hay revealed that only 3.3 percent of the 

 estimated 317 waterfowl nests present produced 

 young in 1963. Alfalfa mowing accounted for 

 74.2 percent of the nest dastruction. Commercial 

 hav cutting, with its short cutting cycles, was very 

 detrimental to nesting success in first-cut alfalfa 

 becau.se it occurred during the peak of nesting. 



Cylindrical, open-end nesting structures made of 

 poultrj' netting and marsh grasses were erected in 

 1961 and surveyed during the duck-nesting seasons 

 of 1962 and 1963. Two of 100 structures (2 per- 

 cent) were used by nesting ducks in 1962, and 11 of 

 89 structures (12.4 percent) were used in 1963. 

 Nesting success was 81.6 percent (9 of 11 nests) 

 in 1963. It was concluded that a greater percent- 

 age of the area's duck production potential could 

 be realized by the provision and maintenance of 

 these structures. 



Pothole permanency in relation to seasonal 

 waterfowl use. — Studies of the relation between 

 potholes and waterfowl using them were continued 

 during 1964 in the Missouri Coteau areas of 

 Dickey, Stutsman, and Ward Counties, N. Dak., 

 and in a drift prairie area of Stutsman Coimty. 

 The Northern Prairie Center conducted the work, 

 in cooperation with the U.S. Geological Sun-ey, 

 the agencj' responsible for intensive investigation 

 of the hydrological factors aifecting several se- 

 lected pothole units. Habitat conditions in the 

 area of interest ranged from generally good in the 

 soutli to poor in tlie nortli. 



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