164 Roosevelt Wild Life Bulletin 



traced from State land maps given me by Mr. Howard. Many little 

 streams and ponds and other unessential details have been omitted 

 for the sake of clearness. The scale as given on the State maps 

 was two miles to the inch. Reference to these traced maps will show 

 the distribution of the dams and lodges located by myself and also 

 those reported and fairly definitely indicated on my maps by Forest 

 Rangers. The latter will be omitted in the estimates. 



The total number of inhabited lodges found was 84, and of dams 

 in repair, 168. Along a number of the streams explored where no 

 lodges are indicated some doubtless escaped notice, but I believe that 

 this number is not large. It is to be noted that the ratio of lodges 

 to dams is 1 to 2. 



To arrive at an estimate of the number of beaver here represented 

 we may assume that to each inhabited lodge there were at the time 

 two parent beavers and (on an average) 4 young of the season. 

 We may add to this an average of four yearlings which had not as 

 yet built lodges for themselves and would spend the winter in the 

 parental lodge. This makes a total of 10 beavers to each lodge, and 

 the 84 lodges therefore represent a population of 840 animals. (Cf . 

 Seton, '09, Vol. 1, p. 452.) A certain number of beavers undoubt- 

 edly live in bank burrows but judging from the nature of the banks 

 in this territory I believe their number to be small, probably not as 

 great as one-fifth of the number that live in lodges. Assuming, how- 

 ever, that it is a fifth, the bank beavers would number 168. This 

 number added to 840 gives us 1,008 as the number of beavers inhabit- 

 ing the watercourses explored. If we assume further that the 

 remaining watercourses of these districts which I was unable to visit 

 contained an equal number of beavers, the figure becomes 2,016; or, 

 if there were three times as many, which I believe to be improbable, 

 then we have 3,024. 



We may now turn to the figures representing the Rangers' beaver 

 dam reports previously mentioned and see what estimates may be 

 derived from that source. These estimates so far as they concern 

 Herkimer and Hamilton counties may be considered independently 

 of those given above in connection with my own investigations, but 

 it is well to bear in mind that the districts covered by me are included 

 in the area in which, as will be seen later on, the majority of the 

 beaver dams reported by the Rangers are located. My purpose is to 

 arrive at some estimate of the number of beaver in Herkimer and 

 Hamilton counties and in the Adirondack region as a whole, on the 



