BATS IX RELATION TO GUANO AND IXSFXTS 



9 



occupied by bats, and others built in Florida and Georgia had failed 

 to attract bats up to March, 1924. So far as can be learned, the bat 

 roost at Mitchell Lake, near San Antonio, is the only one of the 

 eight built that has been occupied by bats, but this does not mean 

 that others in favorable situations may not attract them. 



There would be many advantages in being able to colonize bats 

 successfully in certain localities either in artificial roosts or artifi- 

 cial caves and tunnels, but so far none of the experiments can be 

 considered entirely successful. Doctor Campbell's experiment is 

 interesting as far as it reaches, but 

 so far it has succeeded in only one 

 case and with only one species 

 of bat. 



The choice of roosting places by 

 bats is evidently dependent upon 

 factors not always readily under- 

 stood. In many cave regions where 

 bats are abundant, only certain of 

 the numerous caves available and 

 apparently suitable are actually oc- 

 cupied. Although bats may in 

 some instances be attracted to arti- 

 ficially prepared roosts, prospective 

 builders should be informed, before 

 deciding to risk what may be a 

 needless expenditure of funds, that 

 there is no assurance that such 

 structures will be used (fig. -i). 



BUILDINGS OCCUPIED 



Fig. 4. — Bat roost noar Military Acad- 

 emy, San Antonio, Tex., built by pop- 

 ular subscription in 1920 at a cost 

 of $2,000, for mosquito control, but 

 never occupied. In only one of eight 

 such structures, from Florida to 

 Texas, have bats taken up their abode 



The walls or attics of many old 

 buildings in San Antonio. Austin. 

 Del Rio, and other communities in 

 western Texas are occupied by 

 these bats. In 1923 two wagon- 

 loads of bat guano were taken out 

 of the attic of the courthouse at Austin, and the openings carefully 

 closed to prevent the return of the bats. The strong odor of the bats 

 and guano rendered the building unendurable for human beings, as 

 it has in the case of many private dwellings where the bats have 

 taken up their abode in hollow walls or attics. To prevent their, 

 return, however, it is only necessary to close all openings in the 

 buildings at night when the bats are out. 



In the vicinity of Patzcuaro. Miehoacan. at an altitude of 7.500 

 feet, the writer found Tadarida mexicana the most common species 

 of bat, although the summer climate here was much cooler than in 

 the localities most frequented by them. Here they were sometimes 

 found in caves, but were more numerous among the tiles and other 

 crevices in the roofs of the houses, and in openings in larger build- 

 ings as well. In an old building in the middle of Patzcuaro. where 

 these bats were clinging in great numbers to the ceilings of two 

 rooms, the owner made a regular business of gathering the guano 



