4. A large house at the mouth of Nicollet Creek at the 

 south end of the west arm. This house was deserted for sev- 

 eral years, but in the fall of 1912 the beaver repaired to it 

 and it was inhabited during the winter of 1912-13. It is one 

 of the largest houses in the park, and during the winter it 

 could be seen as a white dome for the distance of a mile. It 

 is not a pond house, but is built like a pond house on the 

 wide mouth of Nicollet Creek. 



."). There is a large house in a pond on Boutwell Creek. In 

 November or December, 1912, the beaver deserted this house 

 and I found the pcnd drained. It will be of interest to learn 

 whether in the summer of 1913 the beaver will again move 

 into this pcnd and repair the dam and the house. There is 

 also an old deserted house near the mouth of Boutwell Creek. 

 This house I opened in 1908, when it was already deserted. 



6. In a dry pond near the mouth of Nicollet Creek may be 

 seen two deserted houses. 



Observing Beaver. 



Dining the summer of 1912 I spent about a month in study- 

 ing the works and habits of the beaver. The animals, how- 

 ever, were so very shy that it proved difficult to observe them 

 the afternoon, a beaver would appear within an hour or two, 

 swim past the breach and then vanish not to return, but the 

 breach was repaired during the night. 



As I desired very much to obtain some reliable first-hand 

 observations on the habits and the number of beaver in a 

 house, I built a platform, attached to three poplars near a 

 beaver house just west of the park on a point of land project- 

 ing into a small lake. The platform was spiked to the trees 

 about twenty feet above the ground, and from this place I 

 frequently watched for beaver from about four in the after- 

 noon until dark. 



About 6:30 two large large beaver generally left the house 

 and, swimming slowly, scouted along the shore for scents of 

 danger. They always left under water, and I actually saw 

 one leave only twice. On one occasion, the dark body of the 

 beaver looked like a giant black turtle, and on another occa- 

 sion I could trace the beaver by a line of rising bubbles. 



15 



