Big Game Animals of the YeUozvstone 453 



ebb.* Unfortunately, deer cannot be held and grazed within the Park 

 through the winter as can the antelope, as they will go higher on 

 the hills and around or over the fence built across the valley flats 

 10 restrain the latter. 



MOUNTAIN SHEEP OR BIGHORN 



Oi'is canadensis Shaw 



: The bighorns or mountain sheep are a source of much anxiety and 

 concern to the Yellowstone Park staff. Their numbers have de- 

 creased rapidly since former times, but whether they are still declin- 

 ing is not known. 'My attempts to find them in summer and fall 

 were not very successful, and I feel that they are, next to the white- 

 tailed deer, the rarest hoofed game in the Park. In 1907 they were 

 estimated by the rangers at 200, in 1910 at 150, and in 1916 at about 

 no. What their numbers are at the present time we can only guess.' 

 I saw in three months' search some 28 individuals, 12 of which were 

 ewes and young lambs, and 16 were adult rams. The ewes had a 

 fair proportion of lambs with them and seemed to be increasing 

 normally. The rams were seen in late November after several heavy 

 snowstorms. I should say that 100 bighorn sheep would be a very 

 liberal estimate for Yellowstone Park, an area that should harbor 

 at least 1000, after forty years of protection. * * 



It is somewhat difficult to sift evidence concerning the decrease in 

 the number of sheep. It is doubtful if many wander out of the 

 Park as they are usually local in habitat and are not affected in the 

 least by the severity of the winter weather. These animals are not 

 nervous, and inhabit regions where they are not subject to molesta- 

 tion. They eat hay which is placed near Gardiner Canyon road in 

 winter, but they do this merely as a change in diet and not because 

 they are in want of food. There may be some killing of these 

 native sheep by poachers in the eastern portion of the Park, but not 

 to an extent that would account for their diminished numbers. 



The reason that seems most plausible is that the bighorns were 

 infected by "scab," contracted from tame sheep that were driven 

 through the Park. Scab is caused by a mite, and in domestic sheep 

 is not a fatal disease. To the bighorn it seems to be deadly. The 

 ears are attacked first, and become closed, rendering the animal deaf. 

 Tales came to us of sheep country in the Hoodoo Mountains in the 



* The last of the white-tailed deer seem to have disappeared from the Yellowstone 

 Park in 1923. 



* In 1923 the bighorns were definitely seen to be increasing, over fifty being reported 

 in one band on Specimen Ridge in August. 



4 



