452 Life-histories of Northern Animals 



Beaver is supposed to add 20 per cent, per annum to its popu- 

 lation, therefore 1,000,000, being somewhat over 20 per cent., 

 would leave us about 5,000,000 as the possible original popu- 

 lation. 



Approaching the question in another way: In the late 

 50's L. H. Morgan explored thoroughly a Beaver country on 

 the south-west shore of Lake Superior, immediately west of 

 Marquette. It was 6 by 8 miles. In his map^ of this he shows 

 63 dams and 39 lodges. Each lodge was estimated to repre- 

 sent 7 Beaver, that is, 273 in all, or 5§ to the square mile. 

 But he mentions that only a portion of the lodges are shown 

 on the map. A reading of the text leads us to believe that the 

 number was double those marked, so that the ratio may have 

 been 10 to the square mile. 



From all accounts they were much more numerous in 

 British America and in the Rockies, where, according to 

 Prevost,^ one trapper sometimes took 500 Beaver in the year. 

 But they were much less abundant in the Plains country and 

 Mississippi Valley proper, therefore 3 to the square mile is 

 a reasonable estimate. The entire Beaver range is about 

 6,000,000 square miles, so that 18,000,000 might have been 

 the total population. With these figures in view one is safe 

 in setting the original Beaver population at not less than 

 10,000,000 in years of abundance. "'- 



The Hudson's Bay Company still draws 30,000 to 50,000 

 Beaver skins per annum from its territories, while rival traders 

 secure at least a third as many. The destruction from various 

 other causes will easily bring the total to 100,000 per annum, 

 and since the species is able to stand it, I believe this drain 

 to be not more than 20 per cent, of the present numbers, or 

 about 500,000. 



^ In The American Beaver and His Works, 1868, a standard volume which must be 

 the starting-point for all Beaver studies, p. 82. 



" Quoted by Aud. & Bach., Quad. N. A., 1849, Vol. I, p. 354. 



°^ Dr. T. S. Palmer tells me that in the Algonquin Park, which is nearly 2,000 

 square miles, the Beaver population is estimated at 100,000, or 50 to the square mile. 

 This represents maximum abundance. If there is no error in the figure, it means that 

 my estimate of the primitive Beaver population in North America should be multiplied 

 at least by 5. E. T. S. 



