ELLIOTT ET AL.: THE CAVE FAUNA OF CALIFORNIA 
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Table 10. Bats known from California’s caves, mines, and tunnels. 
Family 
Species 
Common Name 
Molossidae 
Eumops perotis 
Western Mastiff Bat 
Molossidae 
Tadarida brasiliensis 
Mexican Free-tailed Bat 
Phyllostomidae 
Macrotus californicus 
California Leaf-nosed Bat 
Vespertilionidae 
Antrozous pallidus 
Pallid Bat 
Vespertilionidae 
Corynorhinus townsendii 
Townsend's Big-eared bat 
Vespertilionidae 
Eptesicus fuscus 
Big Brown Bat 
Vespertilionidae 
Euderma maculatum 
Spotted Bat 
Vespertilionidae 
Lasionycteris noctivagans 
Silver-haired Bat 
Vespertilionidae 
Myotis californicus 
California Myotis 
Vespertilionidae 
Myotis ciliolabrum 
Western Small-footed Myotis 
Vespertilionidae 
Myotis evotis 
Long-eared Myotis Myotis 
Vespertilionidae 
Myotis lucifugus 
Little Brown Myotis 
Vespertilionidae 
Myotis melanorhinus 
Dark-nosed Small-footed Myotis 
Vespertilionidae 
Myotis occultus 
Arizona Myotis 
Vespertilionidae 
Myotis thysanodes 
Fringed Myotis 
Vespertilionidae 
Myotis velifer 
Cave Myotis 
Vespertilionidae 
Myotis volans 
Long-legged Myotis 
Vespertilionidae 
Myotis yumanensis 
Yuma Myotis 
Vespertilionidae 
Parastrellus hesperus 
Western Pipistrelle, Canyon Bat 
Family Molossidae, Free-tailed bats 
Free-tailed bats are represented in California caves and mines by two species: Eumopspero- 
tis, 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 (Cock- 
rum 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. 
Family Phyllostomidae, Leaf-nosed bats 
The California leaf-nosed bat, Macrotus californicus , was reported in 11 mines in the Mojave 
Desert and several caves in southern California. The largest colonies were 500 in a mine in Impe¬ 
rial County in 1924 (U.S. Geological Survey 2016b), 300 in caves in Coachella Valley, Riverside 
County, Mojave Desert, in 1908 (Grinnell 1918); 150 in an unnamed mine, and 30 in an unnamed 
cave, both in Imperial County in 1918 (Howel 1920). The most recent report was 200 seen in a 
mine in San Bernardino County in 1983. This is the only leaf-nosed bat in the U.S. with large ears. 
They forage by gleaning larger insects off the ground and other surfaces. They are susceptible to 
