Fringed Myotis (Myotis thysanodes) 



Description: A medium-sized (5-8 g) large-eared myotis. Dorsal pelage varies from medium 

 brown to pale buff, the individual hairs being grayish-black basally. Ears and 

 membranes are blackish brown and often contrast with the pelage color; ears (17-21 

 mm) extend 3-5 mm beyond nostrils when pressed forward. Calcar without a distinct 

 keel A fringe of conspicuous pale, straw-colored hairs extends posteriorly 1-2 mm 

 beyond the edge of the uropatagium. 



Distribution: From southern British Columbia south to southern Mexico and east to western 

 North and South Dakota. 



Habitat and Habits: This bat seems to prefer montane and upland forests, but also appears in 

 desert scrub and some non-wooded areas, such as the Badlands of South Dakota (Jones 

 and Choate 1978). The population in South Dakota (centered in the Black Hills) is 

 isolated from the main range. Commonly roosts in buildings, but also uses caves and 

 abandoned mines. Hibernacula include old mines and caves; this species is a 

 year-round resident in the Black Hills (Turner 1974). Females form maternity colonies 

 of up to several hundred individuals in summer. In the Black Hills (Turner 1974), 

 pregnant females have been found in June, and lactating females have been found in 

 late July and late August. These bats are often observed at dusk foraging along water 

 courses and over standing water. In 1994, an adult non-lactating female was 

 mist-netted over a pond at Reva Gap, Slim Buttes on 14 June (Appendix B3). This 

 represents the first record of this species on the Sioux District. 



Status: Not recorded from the Sioux District prior to 1994; year-round resident and not 



uncommon in the Black Hills (Turner 1974). This species has been recorded only from 

 Slim Buttes on the Sioux District (Appendix B4). The Fringed Myotis is a U. S. Fish 

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



Natural Heritage Program rank: G5; S3 in Montana, S2 in South Dakota on Species of 

 Special Concern lists. 



L5 



