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Yuma Myotis (Myolis yumanensis) 



Description: Closely resembles A/, lucifugns, 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 

 lucifugus (Hofifinann 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 are 

 important habitat for this species, it emerges shortly after dusk to forage low over rxinning 

 water. 



Status: One of the more common bats in Montana west of the Continental Divide (Hofi&nann and 

 Pattie 1968, Hoflmaim ei al. 1969), with specimens from Flaiuead County (West Glacier) 

 south through the Flathead and Bitterroot Valleys. Seven were netted in 1995 on Marten 

 Creek in the Cabinet District on 4 September, one of which was collected; these constitute 

 the first record of this species on the Kootenai National Forest. While not noted during 

 the 1994 survey, this species may have been present at sites where A/vo//5 sp. was 

 detected (most species o^ 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. 

 1990) and British Columbia (Nagorsen et al. 1993). The Yuma myotis is not listed by any 

 federal agency. 



Natural Heritage Program rank: G5; S4. 



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