bats prefer these older trees because they roost in foliage, and 

 older trees provide a combination of shelter, open space to gain 

 flight when leaving the roost, and immediate accessibility upon 

 return. Silver-haired bats appear to prefer older Douglas fir 

 trees because the bark tends to pull away from the bole providing 

 crevices for shelter. Older trees are also may provide roosting 

 crevices or cavities created by wind and lightning damage, shed 

 limb holes, excavations by cavity nesting birds, cracks in the 

 wood, and so on (Perkins and Cross 1988). 



Old-growth ponderosa pine provided some roosting sites, but was 

 not selected as often by bats as old-growth Douglas fir because 

 bark ridges are not as deep and bark exfoliation is not as common 

 in ponderosa pine (Perkins and Cross 1988). 



Bats may roost in numerous sites within a forest exclusive of 

 old-growth timber. Old buildings, including recreational cabins 

 and buildings associated with abandoned mines, provide favored 

 sites for many species, including the Little brown bat and the 

 Big brown bat ( Fenton 1992), but these are often unavailable in 

 much of the forested west. Caves and adits may provide roosting 

 sites for many species of bats (Fenton 1992). Many of the Myotis 

 species, including the Fringed myotis, the California myotis, and 

 the Small-footed bat, have been found roosting in fissures and 

 under rock slabs (Thomas and West 1986). 



32 



