Fringed Myotis (Myotis thyusanodes) is named after the short stiff hairs on its tail membrane.  It is the only bat species to have developed these hairs. Coloring ranges from a pale buff, to a medium brown, with the belly hair being lighter, and wing and tail membranes being much darker. These bats like coniferous forests including ponderosa pine forests like those found in Wind Cave National Park. They have been known to roost in trees, caves, mines, rock crevices and buildings. Up to 1,200 females and young have been found roosting together, but they are usually found in small clusters. Fringed bats are very agile in flight and remain close to tree cover while flying. Fringed bats become active 1-2 hours after sunset and forage over rivers and streams. These bats mate in the fall and store sperm in the females bodies over the winter. Pups are born in June or July. They mature quickly, with pups reaching adult size and flying within 3 weeks.