Adirondack Beaver 165 



basis of dams reported by the Rangers. It may be accepted that 

 many unreported dams existed, and of course many new dams have 

 been built since 1920, but the fact remains that the Rangers' reports 

 constitute the most complete and definite information we have as to 

 the distribution and the relative density of the beaver population in 

 the Adirondack region generally. 



It seems important to mention some points revealed by these 

 reports. With the Forestry Department's maps before me I find 

 that 587 dams for the entire region have been plotted for 1919, 

 and new dams added for 1920 increase the total to 663. Of this 

 number 481 dams are divided between Herkimer and Hamilton 

 counties alone and more than half of these are confined to approxi- 

 mately the northern third of their area. In other words, only a scat- 

 tering 182 out of the total of 663 dams reported for the whole Adi- 

 rondack region are located outside of the two counties named, and 

 these counties together contain the great majority of the beaver 

 population. These facts should be noted since it is usually very easy 

 to gain the impression that because a species of animal is plentiful 

 in one part of a region it is equally abundant in all other parts, 

 although such may be far from the truth. And furthermore, such 

 evidence as the Rangers' reports furnish should be given due con- 

 sideration lest any temptation arise to apply sweepingly drastic 

 measures of control that might properly be applicable only to a part 

 of the region. 



Now as to estimates. Accepting the same ratio of lodges to dams 

 as previously given, the same number of beavers to a lodge and the 

 same fraction of bank beavers, it appears that the 481 dams in 

 Herkimer and Hamilton counties represent 2,886 beavers. And 

 proceeding in the same way with the 182 remaining dams scattered 

 throughout the Adirondacks, we shall have 1,092 beavers outside of 

 Herkimer and Hamilton counties. If all the dams reported should 

 constitute only one-half the number that actually exists we have 

 simply to double the sum of the two figures just mentioned, giving 

 an estimated total of 7,956, or in round numbers, 8,000 beavers for 

 the Adirondack region as a whole. 



Willoughby ('20a, p. 628) states that the Conservation Commis- 

 sion estimates that there are between 15,000 and 20,000 beaver in 

 the Adirondacks. With regard to natural increase Riley ('21, p. 

 205) states that: "Likewise, there is very little information about 

 natural losses and rate of increase. Estimates of the numbers in 



