Biologists test herbicides to find satisfactory methods of controlling alligatorweed and other pest plants in 

 waterfowl habitats. (Photo by Gerald H. Townsend) 



Maintenance of "balance" between two wildlife species or groups dependent on the same habitat is an acid 

 test of management skill. Here, ducks and muskrats meet, the birds requiring a certain amount of water for food 

 production and resting space, and muskrats enough aquatic vegetation to provide their main food supply. For- 

 tunately, the desired balance can be maintained fairly well through careful annual harvest of the muskrat popu- 

 lation. (Photo by V.B.Scheffer) 



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