By Sara Vingiello
Geographic Range
The fringed myotis is found across the western United States. It has been found as far east as the Trans-Pecos region of Texas during summer months, as far north as British Columbia and as far south as Mexico.
(Davis and Schmidly 1994, Nowack 1994)
Habitat
This is a highly migratory species that roosts in caves, mine tunnels, rock crevices and old buildings. Their winter habitat is largely unknown.
(Davis and Schmidly 1994)
Terrestrial Biomes:
savanna or grassland 
.
Physical Description
(0.18 to 0.32 oz; avg. 0.21 oz)
Myotis thysanodes is one of the larger species of the Myotis genus and has a total body length of 85mm, tail length of 37mm, foot length of 9mm and ear length of 16.5mm. Its name comes from the fringe of short hairs that line the interfemoral membrane. This species has a full pelage of light brown on its back and off -white underparts. It has a dental formula of I 2/3, Ca 1/1, Pm 3/3 and M 3/3.
(Schmidly 1991, Davis and Schmidly 1994)
Some key physical features:
endothermic ; bilateral symmetry .
Reproduction
After a gestation period of 50 - 60 days, a single young is born in late June or early July. Young bats are not entirely precocial, but are able to fly in about 16 days.
(Schmidly 1991)
Key reproductive features:
seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous ; sperm-storing .
Behavior
In the southern United States, this species usually arrives around mid-May to begin nursery colonies which may contain hundreds of individuals. Female "nurse bats" remain at the roost to care for the young while other adults are out foraging. Males and females usually do not associate with one another during summer months and males are not normally found within the maternity roosts. The colonies have usually dispersed by the end of October.
(Davis and Schmidly 1994, Schmidly 1991)
Key behaviors:
motile .
Food Habits
Myotis thysanodes feeds mainly on beetles and other insects and appear in the late evening. Observations indicate that this species uses its ability for highly maneuverable flight to forage close to the vegetative canopy. It has been suggested that the fringe of hairs along the uropatagium is used to trap small insects.
(Davis and Schmidly 1994, Glass and Gannon 1994)
Economic Importance for Humans: Positive
Bats act as an essential past control by eating hundreds of pounds of insects each night that they forage. They are of great interest to farmers for this role in preventing crop destruction by the insects without the use of harmful chemicals and pesticides.
(Schmidly 1991)
Contributors
Sara Vingiello (author), Southwestern University.
Stephanie Fabritius (editor), Southwestern University.
