18 CONDITION OF ELK IN JACKSON HOLE, WYOMING. 



mild winters and in times of plentiful food supply, many of the older 

 animals of both sexes die. Owing to the fact that a large proportion 

 of the animals killed for food during the autumn months are females, 

 a great many young calves are left motherless and are in a more or 

 less weakened condition when winter comes on. Furthermore, 

 many of the late-born calves are poorly equipped to withstand the 

 winter, and this is likely to be true also of many of the cows which 

 have borne and nursed young the previous season. 



A conservative estimate places the number of elk which died of 

 starvation in the Jackson Hole region during the winter of 1910- 

 11 at some 2,000 to 2,500. Of these, by far the greater number 

 were calves of the previous year. Probably 75 per cent of the 

 calves which came into the valley in November and December had 

 perished of starvation before the end of the following March. In 

 some bands the loss of calves was as high as 90 per cent, but other 

 bands suffered less. The greater part of the loss occurred before 

 feeding began, but large numbers, both calves and older animals, 

 were so weak that they died even when receiving what would ordi- 

 narily have been an abundance of food. Many, in fact, on being fed 

 after a period of starvation, die almost immediately. There is 

 evidently little difference in the relative mortality of the sexes in 

 adult elk, and out of 75 calves examined for sex 32 were males and 

 43 were females, indicating that in the case of the young the burden 

 on the sexes is not strikingly unequal. 



HABITS IN SPRING AND EARLY SUMMER. 



As spring advances and the sides of hills bordering the valley 

 become bare, the elk, especially the older animals, leave their haunts 

 in the lower part of the valley and seek the hillsides, where they 

 subsist on the dry grass which has been exposed by the melting of 

 the snow. At the time of my arrival, about the middle of March, 

 they had already begun to work back into the hills, and the numbers 

 being fed were much less than originally. Many of the animals at 

 this season spend a part of their time on the hillsides, visiting the 

 feeding grounds at the time when they have been accustomed to be 

 fed. As the spring advances, this movement into the hills becomes 

 more and more pronounced, until the valley is entirely deserted. 

 The last ones left that part of Jackson Hole south of the Gros Ventre 

 Buttes, known locally as South Park, about April 26, some time after 

 feeding of hay had been discontinued. They were subsisting on 

 the green grass then springing up on the borders of some spring-fed 

 creeks. They were seen on the adjacent hillsides until early May. 

 In the swamp north of Jackson a large herd remained later. Inves- 

 tigation showed that they were feeding on the green leaves of the 



