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Assessing Breeding Populations of Ducks by Ground Counts

Table 3

Table 3. Sex ratios of ducks, 1956 to 1959, Kindersley Study Area. From counts taken of spaced birds (not migrating flocks) before the first clutches were found.

Year Mallard Pintail Widgeon Gadwall Shoveler Blue-winged teal Green-winged teal Canvasback Redhead Lesser Scaup Ruddy duck
No. % male No. % male No. % male No. % male No. % male No. % male No. % male No. % male No. % male No. % male No. % male
1956 364 54 -- -- 179 50 319 53 35 -- 113 52 94 51 15 -- 98 51 807 55 59 58
1957 -- -- -- -- 312 51 98 51 196 56 225 56 100 57 72 68 139 66 785 59 -- --
1958 310 52 393 55 550 53 181 53 148 53 80 54 352 54 24 -- 171 57 1133 63.5 97 53
1959 358 53 235 53 493 52 175 51 184 54 104 54 135 55 65 55 370 56 2003 63.2 435 66
Total 1032 52.8 628 54 1534 51.9 773 52 563 54 522 55 681 54 176 61 778 57 4728 61.1 591 63
95% con. int. ± 3.0 ± 4 ± 2.6 ±4 ± 5 ± 5 ± 4 ± 7 ± 4 ± 1.4 ± 4
Mean ratio M;F this study 112:100 117:100 108:100 110:100 119:100 120:100 110:100 159:100 134:100 157:100 172:100
Bellrose et al.* (1961:428) 105:100 119:100 129:100 112:100 123:100 133:100 121:100 174:100 127:100 195:100 211:100
Bellrose et al.^ (1961:416) 117:100 142:100 116:100 121:100 139:100 117:100 115:100 132:100 111:100 154:100  
*Recalculated from Table 34, for Saskatchewan, Minnesota, Manitoba, and North Dakota.
^Recalculated from Table 27, for Manitoba, April 21 or April 29 to May 7.
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