ELLIOTT ET AL.: THE CAVE FAUNA OF CALIFORNIA 
47 
elevations and thus are relatively warm. Pierson and Rainey (1994) and Pierson and Fellers (1998) 
reported a significant decline in big-eared bats in California caves, mines, and buildings; there has 
been a 52% decline in the number of known maternity colonies. The species is sometimes fright¬ 
ened out of caves by humans, but it may re-establish later, especially bachelor colonies. There are 
few sites that have had regular, long-term bat counts. Parrish Cave, a lava tube in Shasta County, 
had winter bat counts in 1948-1951, 1955, 1957, 1960, 1966, 1987, 1988, 1991, and 2015. The 
largest count was 201 in 1948, the smallest was 11 in 1988 and 1991. A graph of the counts, 
grouped by decades, could be interpreted as a long-term decline except that there were two data 
gaps of 21 and 24 years, then the colony peaked again at 177 in 1987. The cave is heavily visited 
by tourists. 
Although C. t. townsendii was being considered for listing, it is still listed as Least Concern by 
IUCN because of its wide distribution, presumed large population, occurrence in a number of pro¬ 
tected areas, and because it is unlikely to be declining at the rate for listing in a threatened catego¬ 
ry. There are two subpopulations/subspecies that are listed as endangered by the U.S. Fish and 
Wildlife Service {ingens and virginianus ) (International Union for the Conservation of Nature 
2016). A series of further, regular hibernation and maternity colony counts at a few sites would help 
in monitoring the status of this species, but they must be done carefully by professionals to limit 
disturbance. 
Eptesicus fuscus, Big Brown Bat, is common across North America, and it has been reported 
from five caves, one crevice, three mines, and two tunnels across California. Suggett (1982) report¬ 
ed the subspecies E. f. bernardinus Rhoads in Upstairs-Downstairs Cave, Siskiyou County. Most 
summer roosts are attics, bams, bridges or other man-made structures; they move into caves, mines 
and crevices to hibernate only during the coldest weather conditions, and they usually vacate with¬ 
in weeks. 
Euderma maculatum, Spotted Bat, was reported from a spring cave, San Bernardino County, 
in 1948 by Parker (1952) and V. Johnson (1990). It is otherwise known from southern California 
from a few buildings and a cliff face, and in one instance from a garage in Shasta County. 
Lasionycteris noctivagans, Silver-haired Bat, is widespread in North America but has only 
been found in a mine in Inyo County (V. Johnson 1990; Szewczak et al. 1998). The bat is solitary, 
dark-colored, and difficult to identify on cave or mine walls. 
Myotis californicus, California Myotis (Fig. 95 and front cover), is known in small numbers 
in eight caves and five mines from the Mojave Desert to northern California. The species also 
roosts in rock crevices, tree cavities and loose bark, and buildings. 
Myotis ciliolabrum, Western Small-footed Myotis, seeks cover in crevices, caves, mines and 
buildings. Besides five mines in the Mojave Desert, it is known from two lava caves in Siskiyou 
County, where five to 12 bats were caught with harp traps in 1990 and 1999. One was a lactating 
female in Heppe Ice Cave. These records hint that many cave bat colonies are still unidentified in 
California. 
Myotis evotis, Long-eared Myotis, has daytime roosts in buildings, tree cavities, caves, mines, 
and rock crevices. The species has been found in one tunnel, one mine, and ten caves. 
Myotis lucifugus, Little Brown Myotis, is widespread in the U.S. and Canada, although it has 
declined greatly in the east because of White Nose Syndrome, and it is being considered for listing 
as endangered. The disease was found in this species in March 2016 in King County, Washington 
(U.S. Geological Survey 2016a). In summer M. lucifugus inhabits attics or other shelters near 
water, and it hibernates in caves and mines, formerly in large numbers in the eastern U.S.A. In 
California it has been found in small numbers in six caves and one mine, from the Mojave Desert 
to Lava Flows North. 
