Yuma Myotis {Myotis yiimcmensis) 



Description: Closely resembles M. lucifitgns, but somewhat smaller with duller, shorter pelage. 

 Basal fur on shoulders is lighter colored, and the ears are paler. Ears do not extend 

 beyond the tip of the nose when pressed forward. Foot relatively large (9-10 mm); the 

 calcar is not keeled. 



Distribution: In western North America from British Columbia to central Mexico, west of the 

 1 00th meridian. 



Habitat and Habits: Appears to be closely associated with water, often in relatively open terrain 

 with sparse tree cover. Hibemacula include mines and caves; roosts include buildings, 

 hollow trees and under bark, caves, and mines. Often found in mixed colonies with M. 

 liicifugus (Hoffmann and Pattie 1968). Females form maternity colonies, with young 

 bom in June in British Columbia (Fenton et al. 1980, van Zyll de Jong 1985). Streams 

 ai-e important habitat for this species; it emerges shortly after dusk to forage low over 

 running water. 



Status: One of the more common bats in Montana west of the Continental Divide (Hoffmann 

 and Pattie 1968. Hoffmann et al. 1969), with specimens from Flathead County (West 

 Glacier) south tlirough the Flathead and Bitterroot Valleys. Wliile not noted during the 

 1994 survey, this species may have been present at sites where Myotis sp. was detected 

 (most species oi Myotis are not easily distinguishable with bat detectors). Present in the 

 Idaho panhandle (Groves and Marks 1985). Most individuals probably winter outside of 

 the region; there are single winter records from Oregon (Perkins et al. 1 990) and British 

 Columbia (Nagorsen et al. 1993). The Yuma Myotis is a U.S. Fish and Wildlife Service 

 candidate (C2) species for federal listing. 



Natural Heritage Program rank: G5; S3 on Montana Species of Special Concern list. 



11 



