ABSTRACT 



The muskrat, largely an inhabitant of low, sub- 

 marginal lands unsuited to agriculture, is the Nation's 

 greatest fur resource, and the trapping and handling 

 of its pelts has developed into an important and valuable 

 industry. 



Despite a high reproductive rate and a remarkable 

 ability to maintain itself year after year under unfavor- 

 able conditions, the muskrat is subject to cyclic fluctua- 

 tions. Periodic reductions in its numbers create con- 

 siderable apprehension in trappers and others concerned 

 about its welfare, and result in many requests for 

 information regarding it. 



This circular gives facts on the biology and ecology 

 of the muskrat, and discusses basic principles of marsh 

 management that underlie practical muskrat produc- 

 tion. The material is based on many years of research 

 by the author and numerous other Federal and State 

 workers, and on experiences and observations of many 

 owners of marshes in commercial muskrat production, 

 muskrat trappers, and fur dealers. 



