262 AUDUBON THE NATURALIST. 



have notice of ttie approacli of winter weather, 

 and of its probable severity, by observing the 

 preparations made by the beavers to meet its 

 rigours ; as these animals always cut their wood 

 in good season, and if this be done early, winter 

 is at hand. 



The beaver dams, where the animal is at all 

 abundant, are built across the streams to their 

 very head waters. Usually these dams are 

 formed of mud, mosses, small stones, and 

 branches of trees cut about three feet in length 

 and from seven to twelve inches round. The 

 bark of the trees in all cases being taken off 

 for winter provender, before the sticks are car- 

 ried away to make up the dam. The largest 

 tree cut by the beaver, seen by Prevost, meas- 

 ured eighteen inches in diameter ; but so large 

 a trunk is very rarely cut down by this animal. 

 In the instance just mentioned, the branches 

 only were used, the trunk not having been 

 appropriated to the repairs of the dam or 

 aught else by the beavers. 



In constructing the dams, the sticks, mud, 

 and moss are matted and interlaced together 

 in the firmest and most compact manner; so 

 much so, that even men cannot destroy them 

 without a great deal of labour. The mud and 

 moss at the bottom are rooted up with the 

 animal's snout, somewhat in the manner hogs 



