MAMMALS IN THEIR RELATION TO SPOTTED FEVER. 



11 



of Darby. I shot three in the middle of May on Rock Creek near 

 Lake Como, and secured records of their occurrence on Bass. Mill, 

 Blodgett, Sawtooth, Lost Horse, and other creeks entering the Bit- 

 terroot from the west. They inhabit the broken precipices along the 

 creeks at from 5,000 to 7,500 

 feet altitude. 



I believe that in proportion 

 to their numbers mountain goats 

 serve more frequently as hosts 

 for fever ticks {Dermacentor 

 venustiis) than do any other 

 wild animals. Of the three in- 

 dividuals shot each was infested 

 with a hundred or more adult 

 and a few nymphal ticks. 

 Hunters say that goats killed at 

 all seasons harbor ticks, which 

 are very abundant on the goat 

 rocks where there are no other 

 large mammals. Many Derma- 

 centor alhipictus also were 

 found on these goats. 



FLYING SQUIRREL. 



{Sciuropterus alpinus.) 



Flying squirrels occur 

 throughout the higher forests of 

 the Bitterroot Mountains and 

 occasionally follow the creek 

 well down into the valley. 

 Two adult and several young 

 of this species were examined 

 and all were tick free. The 

 number examined is insufficient 

 to prove a negative, but the noc- 

 turnal and arboreal habits of these squirrels may render them 

 immune from ticks. 



* PINE SQUIRREL. 



(Sciurus hudsonicus richarclsoni.) 



Pine squirrels are abundant throughout the coniferous timber of 

 the Bitterroot Valley and adjacent mountains. Most of those secured 

 in good " tick " country " were found to be infested with nymphal or 

 seed ticksj several dozen seeds being taken from one squirrel. Most 



[Cir. 82] 



Fig. 1. — Flying squirrel (Sciuropteriis al- 

 pinus). (About 3 natural size.) 



