Western Small-footed Myotis i Myotis ciliolabrum; formerly M. leibii ciliolabrum) 



Description: This is the smallest (3-7 g) bat in the area. Dorsal pelage is pale yellowish 



brown to golden brown, contrasting with the blackish ears (13-15 mm) and membranes. 

 The most notable characteristic other than small size is the strongly-keeled calcar (the 

 spur projecting from the ankle which supports the uropatagium). 



Distribution: Ranges over much of western North America from southern Canada to northern 

 Mexico. 



Habitat and Habits: Appears to prefer arid habitats, where it is associated with cliffs, talus, 

 clay buttes, and steep riverbanks. Roosts in crevices in buildings, trees, rock faces, 

 and clay banks, and may use spaces under and between talus and boulders. 

 Hibernacula include caves and abandoned mines in central Montana (Swenson 1970), 

 the Black Hills. SD (Turner 1974), and Idaho (Genter 1986). Tends to become active 

 at dusk and forages low along cliffs and rocky slopes rather than over water. Little 

 information is available on reproduction. One of six females collected in the Long 

 Pines in late June to early July carried an embryo (Jones et al. 1973), a lactating female 

 was collected in Ekalaka Hills on 18 July (Lampe et al. 1974), and females with 

 embryos have been found in mid-June in the Black Hills (Turner 1974). In 1994 2 

 adult males and a juvenile male were mist-netted on 14 June at a pond at Reva Gap, 

 Slim Buttes (Appendix B3). 



Status: Appears to be fairly common on the Sioux District (see Andersen and Jones 1971, 

 Jones et al. 1973). This species has been recorded from Ekalaka Hills, the Long 

 Pines, and Slim Buttes (Appendix B4). The Western Small-footed Myotis is a U. S. 

 Fish and Wildlife Service candidate (C2) species for federal listing. 



Natural Heritage Program rank: G5; S4 in Montana, not on South Dakota Species of Special 

 Concern list. 



