MAMMALS OF THE REGION 113 



when they began to warm up. At 60 degrees they 

 became active, and usually remained so during the day 

 in my room. 



While the bats were hibernating, their stomachs and 

 the whole alimentary canals were empty, no guano 

 being deposited during the winter rest. However, 

 after a warm night in spring when the bats had come in 

 and hung themselves up for the day, there was constant 

 dropping from above of the little dry pellets of 

 excrement. 



The guano deposits in the cave have been enormous; 

 they were one hundred or more feet in width, a quarter 

 of a mile in length, and varied up to a hundred feet in 

 depth. Back beyond all traces of light no live bats 

 were found, and there were no extensive deposits of 

 guano and only a thin layer of scattered droppings in 

 places where bat bones were found. Most of the guano 

 in the cave was removed during the twenty years be- 

 tween 1901 and 1921, and shipped away for fertilizer. 

 Jim White, who had charge of getting out the guano, 

 estimated that during about fifteen years approximately 

 half of each year was devoted to the work, generally 

 from September to March, and that from one to three 

 car loads of guano weighing about forty tons each were 

 shipped each day. A maximum of three car loads a 

 day was shipped at rush times only, but even one car 

 load a day for seven years would amount to consider- 

 ably over one hundred thousand tons of guano taken 

 out of the cave. From twenty to forty men were em- 

 ployed at a time, sacking, elevating, and hauling the 

 guano to the railroad, and night and day shifts were 



