Molossidae, Gervais, 1856

Elliott, William R., Reddell, James R., Rudolph, D. Craig, Graening, G. O., Briggs, Thomas S., Ubick, Darrell, Aalbu, Rolf L., Krejca, Jean & Taylor, Steven J., 2017, The Cave Fauna of California, Proceedings of the California Academy of Sciences 64, pp. 1-311 : 45

Family Molossidae , Free-tailed bats

Free-tailed bats are represented in California caves and mines by two species: Eumops perotis , Western Mastiff Bat, with six cave and crevice records from San Diego to Calaveras County in the Sierra Nevada North, and Tadarida brasiliensis mexicana, Mexican free-tailed bat. Although the latter is the most common cave bat in the southwestern United States, west coast populations inhabit caves infrequently (Barbour and Davis, 1969) and are thought to be nonmigratory ( Cockrum 1969). The literature and cavers reported Mexican free-tailed bats in four mines and 11 caves from San Diego to Colusa County in the North Coast Range. An uncounted cluster was observed in Painted Rock Cave, San Luis Obispo County in 1911 ( Grinnell 1918). An emergence flight of about 95,000 was observed at Bat Cave No. 1, LABE, Siskiyou County , in 2003 ( U.S. Geological Survey 2016b), probably the largest bat colony in the state.