FiGfRE 9. — Occupied muskrat house in "blue flag" cattail ( Typha glauca ) (right) with 

 smaller feeding shelter marsh in central New York. 



remains is usually found just above 

 the water line (fig. 10). Several 

 runs lead from it beneath the water. 

 On the Atlantic coastal marshes 

 where climatic conditions are less 

 severe than on northern marshes, 

 the tightly constructed hut is re- 

 placed by a flimsy feeding shelter. 

 Open feeding platforms are used 

 during the summer, and in more 

 southern areas throughout the year. 



Push-ups or breathers 



Not to be confused with the feed- 

 ing shelter which it resembles super- 

 ficially, the push-up or breather is 

 generally found in the frozen 

 marshes of the northern States and 

 Canada, and is confined to the 

 deeper channels, rivers' edges, and 

 lakes. As soon as ice forms in the 

 fall, the muskrats start building 

 push-ups by cutting holes in the ice 

 about 4 or 5 inches across and push- 

 ing fibrous roots, waterweeds 

 and other submergent vegetation 

 through the openings. This is in 

 marked contrast to the bulkier stems 

 and leaves of cattails and other 



emergents they use in constructing 

 feeding stations. A 12- to 18-inch 

 mass is formed on the ice above the 

 hole, and a cavity is made on the 

 inside which the muskrats use as 

 a shelter and breather. During se- 

 vere weather they also are used as 

 feeding stations. With the arrival 

 of spring and thawing of the ice, 

 the structure collapses. 



Bank dens 



Muskrats living along the edge 

 of woods, stream banks, and drain- 



FiouRE 10. — Feeding shelter with side cut 

 away to expose feeding platform with 

 remnants of winter shoots of "blue 

 flag" cattail left by muskrat. 



210220 O— 53- 



