62 



ANIMAL LIFE IN THE YO SEMITE 



Occurrence. — Resident in Upper Sonoian Zone and lower part of Transition Zone 

 on west slope of Sierra Nevada, where recorded at Coulterville, on Smith Creek (6 miles 

 east of Coulterville), at El Portal, and in Yosemite Valley. One record for Walker Lake, 

 east of Sierra Nevada. Forages high in open air apart from trees or other vegetation. 

 'Eoosts' in buildings. Colonial. 



The Free-tailed Bat is a bat of the open places, and in its route of 

 forage and manner of flight more nearly resembles the swallows than does 



any one of the other local bats. 

 It is to be looked for over fields, 

 or else well above the level of 

 the tree tops or brush. A dis- 

 tinctive feature of this species 

 is the narrowness of its wings, 

 a shape which is perhaps more 

 useful to an animal flying 

 swiftly in the open. 



This bat is highly colonial, 

 sometimes being found in gath- 

 erings which include hundreds 

 of individuals. It seeks by 

 preference the attics of build- 

 ings rather than natural abodes 

 in crevices in trees or cliffs. 



In time of appearance the 

 Free-tailed Bat resembles the 

 Large Brown Bat. Thus, the 

 two species appeared simul- 

 taneously at 7 :30 p.m. in Yo- 

 semite Valley on July 24, 1920. 

 At El Portal, January 1, 1915, 

 a Free-tail was shot shortly after 5 :14 p.m. This latter occurrence indicates 

 not only that this species winters in the region, but also that individuals 

 forage abroad in midwinter when weather conditions are favorable. 



The single example from the east side of the mountains was picked up 

 dead on September 12, 1915, at Walker Lake. 



At Coulterville, on June 7, 1915, two members of our party visited 

 several buildings in the town which were reported to be inhabited by bats. 

 The specimens obtained in one of these places were all Free-tailed Bats, 

 but whether all the buildings had been tenanted by this species could not 

 be ascertained. The attic over the local drug store was a large affair open 

 under the eaves so that bats could easily gain entrance. Only four indi- 

 viduals were seen there at the time of our visit; but on the floor of the 

 place there was bat guano to the depth of 4 inches or more, indicating that 



Fig. 8. Mexican Free-tailed Bat; from speci- 

 men, about %o natural size. Dudley (six miles 

 east of Coulterville), June 24, 1922. 



