108 ANIMAL LIFE OF CARLSBAD CAVERN 



Except for this destruction of bats, which would occur 

 only where large colonies gather, their food habits are 

 largely beneficial in controlling the abundance of 

 rodent and insect pests. 



The ring-tail is most nearly related to the raccoon, 

 but is much smaller and slenderer, with a bright pretty 

 face and large ears, a long flattened, bushy tail with six 

 or seven black bars across the top, and buffy gray fur 

 over the body. 



MEXICAN FREE-TAILED BAT 



Tadarida mexicana mexicana (Figs. 39 and 40) 



The bats of the Carlsbad Cave are not the so-called 

 cave bats of recent literature, but the free-tailed bats, 

 the famous guano-producing species of Mexico and the 

 southern United States, and more than any other group 

 of bats, cave dwellers. They differ from our northern 

 bats in the projecting tail, reaching about an inch beyond 

 the attached membrane, in the short, wide ears, short 

 fur, and in a strong odor peculiar to the group. Their 

 habit of roosting in extensive colonies in caves or build- 

 ings has given them great value in the production of 

 guano, much prized as a fertilizer. These are not the 

 only bats found in the cave, but they are present in such 

 numbers that other species are little noticed. 



The number of bats in the cave varies at different 

 seasons, apparently reaching the maximum in August 

 and September, when they gather for their winter sleep. 

 They hang themselves up under the highest dome of 

 the cave ceiling, one hundred fifty feet above the cave 



