^tUT'^'dtair' ^^-^fcC^r^^' 



Figure 5. — The number of houses on this "three-square" marsh in Maryland indicates 

 a heavy population of muskrats. 



water runoff meet, slightly saline 

 conditions develop. Extensive 

 three-square {Scirpios olneyi, /S. 

 americanus) marshes interspersed 

 with stands of cattail ( Typha spp. ) , 

 reed or "roseau" cane {Phragmites 

 communis)^ and patches of big 

 cordgrass {Spm^tina cynosuroides) 

 result. Soils of these marshes are 

 waterlogged or partially sub- 

 merged, and living conditions for 

 the muskrats approach the ideal. 

 The three essentials required to sus- 

 tain a maximum muskrat popula- 

 tion are met : (1) An abundance of 

 suitable aquatic vegetation for food 

 and protective cover; (2) sufficient 

 fresh or slightly saline water for 

 swimming and proper sanitation; 

 and (3) the most suitable type of 

 bottom (peaty humus) in which to 

 dig canals, underground tunnels, 

 and runways. 



Home of the Muskrat 



Muskrats need little protection 

 during the summer and live in the 



open marsh in almost any kind of 

 makeshift shelter. In the fall when 

 high tides arrive and cold weather 

 approaches, they become very ac- 

 tive, adding to their old houses or 

 pushing up new ones, and digging 

 runways and canals. 



For survival, muskrats depend 

 largely on concealment. They 

 spend much of their lives in their 

 underground tunnels and burrows, 

 in their nests and feeding shelters, 

 in swimming, and in digging and 

 gnawing at the roots of various 



Figure 6. — ^Type of sluice gate commonly 

 used in "diked-meadow" muskrat 

 marshes in New Jersey. 



