392 NORTH AMERICAN FAUNA [No. 55 



Distribution and habitat. This large medium pale bat ranges over 

 probably all of the Upper Sonoran Zone of eastern Oregon, south- 

 eastern Washington, and northern Nevada (fig. 102). There are 

 specimens from Twelve Mile Creek, Crook County; Riverside, Mal- 

 heur County ; Home, Baker County ; and The Dalles, Wasco County. 



The specimen from The Dalles, collected by Dr. Suckley, July 2, 

 1855, is now represented in the National Museum collection by a 

 fragment of the skull only, the rostrum and lower jaws, but from 

 the teeth it seems referable to this form rather than to pacificus. 



A single specimen from Twelve Mile Creek was taken on July 3, 

 1896', and others at Eiverside on July 20, still others at Home on 

 June 30, 1916. Apparently these are all breeding or breeding-season 

 records. 



General habits. In most cases these bats are found in the can- 

 yons or near cliffs and canyon walls where they find shelter in caves 

 and cracks among the rocks. At Riverside, Sheldon in passing a 

 high cliff heard a continuous squeaking up among the rocks and 

 with a long stick poked out several of the bats and shot a couple 

 of them in the bright light of midday. At the type locality of the 

 species Cantwell found them flying in large numbers near a cliff 

 where there was a bat cave, but where the bats were hidden away 

 beyond reach. 



In western Nevada on June 27, 1927, on the western edge of the 

 Carson Valley there was a breeding colony of these bats located in 

 small cavities in the roof of an open cavern. They were constantly 

 squeaking and making many sharp little querulous sounds as if 

 crowded for room and quarreling for the best places. They were 

 entirely out of reach by any convenient method, and to procure 

 some specimens it was necessary to fire a small load of fine shot into 

 one of the cracks in the roof. A considerable number of the free- 

 tailed bats (Tadarida mexicana) were brought down and 2 of the 

 pale bats, each with 2 young clinging to her nipples. The two smaller 

 young were apparently but a day old, male and female, eyes closed, 

 hairless and with rudimentary wings more like hands than wings, 

 the thumb with sharp hook and fingers only partly webbed. The 

 hind claws were well developed, sharp, curved, and highly functional 

 in clinging to the body of the mother. The mouths were well 

 armed with minute, sharp, and curved teeth of the milk dentition, 

 exceedingly efficient in clinging to the mother's wide flat nipples. 

 Even a little of the surrounding fur seemed to be drawn into the 

 mouth with the nipple as an aid to maintaining a hold. The two 

 larger young clung so tightly to the nipples of their dead mother that 

 in trying to remove them there seemed danger of pulling their heads 

 off. They clung with both teeth and claws, and the old bat could 

 easily be picked up by taking hold of one of the young. Their 

 strongest instinct seemed to be to hold on. 



The next day one of the young bats was removed from its dead 

 mother and placed on the breast of the female that was only slightly 

 injured. It at once caught a mouthful of fur, and soon found the 

 nipple and got a good hold of it. The old bat soon recognized the 

 fact that it was not her own young and tried to push it away with 

 her wings but failing in this she took hold of its head in her mouth 

 and forcibly tore it loose from her breast, and pushed it from her 

 leaving tooth marks in its head and one ear. 



