NUMBER OF ELK. 13 



River, and in the Gros Ventre Range to the southward between the 

 Snake and Green River Valleys. A few hundred animals from the 

 more, easterly of these bands probably winter in the Green River 

 Valley, but most of them seek Jackson Hole at that season. 



Most of the residents consider that the elk have increased in num- 

 bers within the last 10 years, but nearly all agree that there has been 

 a decided decrease within the last 3 years. This is owing, of course, 

 to the large number which died during these winters because of 

 abnormal conditions. 



Assuming that the elk number 20,000 and that the number of each 

 sex is approximately the same, the herd just before calving time 

 following a normal winter will be divided approximately as follows: 



5,425 cows 4 years old and over. 



1,200 cows 3 years old. 



1,500 cows 2 years old. 



1,875 female calves. 



10,000 females in all. 



10,000 males in all, of approximately the same relative ages. 



20,000 



It is elsewhere estimated that from 2,000 to 2,500 elk starved to 

 death in the Jackson Hole region in the winter of 1910-11, and it 

 must be borne in mind that this disastrous season was preceded by 

 two others notable for heavy loss. It is plain that the animals can 

 not maintain their numbers under such drains. But so high is the 

 birth rate that elk will hold their own under a considerable winter 

 loss. 



The estimate already given is that a band of 20,000 elk will include 

 about 6,625 cows 3 years old and over, of which about 75 per cent, 

 or 4,968, will drop calves each year. If, then, the elk are not to 

 fall below their present numbers, the total deaths from all causes must 

 not exceed 4,968 per year; or, in other words, the total deaths each 

 year may rise to 4,968 and still the elk will hold their own. 



The total death roll is the result of four causes : (1) Natural causes, 

 including accidents; (2) starvation; (3) wolves and other predatory 

 animals; (4) hunting. It is evident that anything done to decrease 

 losses from the first three causes will increase the number of elk that 

 can be shot each year without diminishing the herd as a whole. But 

 just in proportion as starvation or wolves claim a greater number of 

 victims must the number shot be curtailed, or else the total of the 

 elk will be diminished. 



At present, probably about 2,000 elk a year are killed by hunters 

 and about 1,000 by wolves. If these figures are approximately 

 correct, and if it is also true, as claimed, that under normal winter 

 conditions the elk hold their own notwithstanding these heavy losses, 

 then it follows that of the calves dropped each year (approximately 



