209 
Transects IITA, IV, VIA and VIII which showed largest decreases were ali 
in the northern or central part of the State where the number of water areas in May 
was also down 16 percent as compared to 4 percent on all transects. 
The increase in gadwall cannot be accounted for and neither can the decrease 
in scaup and ruddy ducks which showed a good increase during the May breeding 
pair count. It is possible that a brood count made one week later would have 
produced a few more scaup and ruddy duck broods. 
The following table and graph show the relative abundance of waterfowl in 
both North and South Dakota for the five year period 1948-1952. With the exception 
of 1950 the total pairs per square mile did not vary a great deal on the 225 square 
miles of ground transects. 
Table VII - Relative Abundance of Ducks in the Dakotas for the 5-Year Period 
(Breeding Pairs per Square Mile on 225 Square Miles of Ground Transects) 
1948 through 1952 

5-Year 
Species 1948 1949 1950 1951 1952 Average 
B-w. teal 7.7 8.8 12.6 9.3 9.5 9.6 
Pintail 4.9 6.0 9.4 6.5 7.2 6.8 
Mallard 3.1 4.7 5.4 3.8 4.5 4.3 
Gadwall 2.3 2.8 2.9 2.4 2.5 2.6 
Shoveler z.0 1.9 2.9 2.1 1.7 2.1 
Redhead 0.8 0.9 1,0 0.9 1.0 0.9 
Ruddy duck 0.7 0.8 1.0 0.6 0.6 0.7 
Canvasback 0.3 0.4 0.7 0.6 0.5 0.5 
Lesser scaup 0.2 0.3 0.2 0.5 0.7 0.4 
All Others 0.3 0.6 0.8 0.4 0.5 0.5 
Total 22.35 27.2 36.9 2%e1 28.8 28.4 
Water Areas Per 
Sq. Mile 9.7 8.1 12.8 11,3 12.6 10.9 
The average of 28.4 ducks per square mile is probably a pair or so above par 
for this area, in fact 1949 and 1951 were normal years in nearly all respects and 
27 pairs per square mile could be considered "par" for the Dakota transects, Notice 
how the 7 most abundant species all follow the general pattern. 
It is also extremely interesting to note the fairly close correlation between 
number of water areas per square mile and the breeding pair population. The. 
number of water areas would have been even higher in 1950 except in many cases 
several small areas weré flooded and joined together making one large area. 
Transects run in 1948 and 1949 were not in the same areas in all cases nor were 
they as extensive as during the period 1949-1952, and while the 1948 and 1949 
transects seemed to give a representative sample of the duck population it was not 
necessarily true of the water areas, 
