60 



YOSEMITE NATURE NOTES 



From Kodtchromt by Andtrson 



Head of Pacific pallid bat. Note the eye. 



flight, yet at no time did they endeavor 

 to get into our hair. 



We have heard the saying, "blind as a 

 bat." Some carry that thought further 

 and believe that bats have no eyes. How- 

 ever, they do have eyes, rather well-devel- 

 oped ones, though comparatively small. 



Since most mammals that are active at 

 night have rather large eyes, the question 

 arises as to how bats can fly with such 

 sureness through the branches of trees 

 and avoid other obstacles in the dark. For 

 that purpose, the eyes seem to be of little 

 assistance to bats. Tests have been made 

 with blindfolded bats in rooms criss- 

 crossed with wires and the animals flew 

 about, rarely hitting the barriers. How- 

 ever, when the ears or mouth were 



plugged, blunders were quite notable. It 

 seems that bats in flight emit sounds of 

 a frequency too high for the human ear 

 to detect. By listening to the variations 

 in the echoes of these sounds, a bat is 

 warned of obstacles in time to avoid 

 them. These sounds should not be con- 

 fused with the high-pitched squeakings 

 that are often heard from bats. 



During the daytime, Yosemite bats 

 hide in rock crevices, caves, buildings, 

 and trees, where they hang upside down 

 and sleep. This upside down posture is 

 facilitated by the strongly curved hind 

 toes and claws. In the winter, some of 

 our bats hibernate, while others migrate 

 to a more temperate clime. 



^ 



Frinn Kodacbrome by Anderson 

 Vf'ing of Pacific pallid bat. Count the fingers. 



While the babies are quite young, they 

 cling to their mother when she is at rest, 

 and she may even carry them with her 

 when she flies forth to forage for food. 



Photo courttty Museum Vrrtebrjle Zoology, Uniiersil\ of Califnrn 

 The spotted bat, rjrest Yosemite mammal. 



