
= PAIRS PER ACRE BY WATER AREA SIZE CLASSES 
(North Daketa - 2,981 Pairs on 934 Water Areas) 
(Seuth Daketa - 2,026 Pairs on 455 Water Areas) 


1949 
3 . 
a 
«< 
2 
s 
1 7 : 
Nort) , 
Sout Dakota 
~_ Dakota 
O-== 1 lil =4 5.1 - 10 10.1 - 20 20.1 - 50 Over 50 
SIZE OF WATER AREAS IN ACRES 
Actually there were more "pairs" on the larger areas, as Table 4 
illustrates, but not on a per acre basis. 
Table 4, -~ Number of Pairs per Water Area 
O =}. bi -/6 5a -wo AO del<eD 20.1 - 50 Over 50 
North Dakota 1.80 4.66 8.77 14.39 21.07 21.00 
South Dakota 1.64 6.20 7.87 10.87 18.71 21.00 
Hatching Success Data 
Nesting studies were carried on incidental to other work on the 68 sample 
areas. Nests were extremely difficult to find and it is felt that this type of 
data can best be obtained in the future through correlation of spring transect 
data with brood data in order to determine nesting success. Table 5 presents 
nest data summarized for both States. 
147 
