The prairie land of Minnesota and the Dakotas is spangled with sloughs and potholes. 

 Here is some of the finest waterfowl breeding range in North America. 



holes create the ideal pattern for the kind of dispersal the breeding pairs 

 like best. Farming country, spotted with marshlets, may hold as many ducks 

 per square mile as do the great marshes like the Delta, or even more, and 

 over vastly many more square miles. The big marshes function as gathering 

 places, spring and fall, as molting areas and summer rendezvous; but they 

 comprise but a fraction of the total nesting range. 



Many regions, like the lake country of Ontario and parts of the Arctic, 

 have a favorable spacing of small waters, but the acid or thin soils do not 

 produce the food or nesting cover plants so attractive to the waterfowl of 

 the prairies. Thus, while the lake country of Ontario or eastern Minnesota 

 may have only two or three breeding ducks to a square mile, the prairie 

 pothole range only a short distance west may attract a hundred or more 

 breeding ducks per square mile. Years ago, Leopold (1931) pointed to 

 this variation, showing how the duck breeding range is to be evaluated not 

 so much by acreage as by quality. The quality breeding range for many 

 of our finest game ducks is on rich land that is also good for man. The 

 millions of acres of slum range can never supply the wildfowling of the 

 future if today's potholes must grow wheat and barley for the next genera- 

 tion. To save this range is going to take better arguments than we have 



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