THE LIFE OF A BEAVER COLONY 89 



There were excellent sites for the two dams which 

 would be necessary. Food was abundant, and from 

 the appearance of the stream, they could count on 

 an ample supply of water. They did not know 

 that many years ago a small colony of beavers had 

 lived there for several years, until a trapper had 

 discovered their home and caught them all. That 

 accounted for the grassy flat and for the division of 

 the stream. In the many years which had passed 

 since that tragedy the trees had grown again. 



As it was too early in the year to attempt much 

 work the prospective house-builders contented 

 themselves with making a deep burrow in the bank, 

 with the two entrances well under water. There 

 they lived for several weeks, when the stream began 

 to dwindle in size as the hot weather dried up many 

 of the smaller tributaries. Then it was advisable to 

 commence work on the dams, and with this object 

 in view they cut a number of alders and laid them 

 lengthways with the banks and across the shallow 

 stream. More and more were added, with clumps 

 of sod and mud worked in on the upper side, so that 

 the flow of water was retarded. At the end of a 

 week, a small pond began to form. This grew 

 larger as the dams were made more solid. At first 

 the large one was not more than twenty-five feet 

 in length, but the engineers decided that if they 

 wanted a pond of sufficient size the length must 

 be extended, and so they built on to the struc- 

 tures until they were nearly doubled in size, and 



