one closes with an otter in a desperate struggle, 

 and when cornered on land one will sometimes 

 turn upon a preying foe with such ferocity and 

 skill that his assailant is glad to retreat. On two 

 occasions I have known a beaver to kill a bobcat. 



Beaver are not equally alert. In many cases 

 this difference may be due to a difference in age 

 or experience. Beaver have been caught with 

 scars which show that they have been trapped 

 before, a few even having lost two feet in escap- 

 ing from traps. On the other hand, skillful trap- 

 pers have found themselves after repeated trials, 

 unable to catch a single beaver from a populous 

 colony. Sometimes in colonies of this kind, the 

 beaver even audaciously turned the traps upside 

 down or contemptuously covered them with mud. 



Nor is the work of all beaver alike. The ditches 

 which one beaver digs, the house one builds, or 

 the dam one makes, may be executed with much 

 greater speed and with more skill than those of 

 a neighboring beaver. Many houses are crude 

 and unshapely masses, many dams haphazard in 

 appearance, while a few canals are crooked and 

 uneven. But the majority do good work, and are 

 35 



