Beaver Castor canadensis canadensis 



near the ground until the tree falls. The branches are 

 then removed and ofttimes the main stem of the tree 

 is cut into shorter lengths, so that they may be pushed, 

 dragged, or rolled into the water. 



In making the dam, the beaver selects a small 

 w^oodland stream. Placing the longer and thicker 

 stems and branches with their large ends up stream, 

 the animal proceeds to carry mud and stones which 

 are piled on the bases. Then the smaller sticks, grasses 

 and green branches are woven together and the crevices 

 are filled with mud and stones. The process of con- 

 struction goes on until the dam is from four to six feet 

 high. The water backs up and forms a good sized pond 

 of comparatively still water. In this pond water lilies 

 and other aquatic plants grow and the beaver feeds on 

 the roots of these. When the trees along the water's 

 edge have all been cut down, as happens when the 

 colony is an old one, the beaver will frequently dig 

 canals from the pond back to the woods. In these 

 canals food is transported and the necessity of dragging 

 sticks and branches from a great distance over land is 

 eliminated. 



-H 125 ><*- /<^> 



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