O’SHEA, CRYAN & BOGAN: UNITED STATES BAT SPECIES OF CONCERN 
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Sixty-seven were observed at seven caves in western Washington during winter months in 1967- 
1971, predominantly males (58 males and nine females) and mostly solitary or as pairs (Senger et 
al., 1974). In Washington and Oregon, they were the most frequently encountered bat found hiber¬ 
nating in searches of 650 caves or mines during winters 1982-1989; none were found in mines, but 
124 were found at eight caves, sometimes in clusters (Perkins et al., 1990). 
Single individuals were observed hibernating in abandoned mines in the San Gabriel Moun¬ 
tains (Vaughan, 1954) and in the White Mountains (Szewczak et al., 1998) of California. Two 
hibernating males were observed in an abandoned mine tunnel in Mohave County, northwestern 
Arizona at about 2,025 meters elevation (Cockrum et al., 1996), and three bats were reported hiber¬ 
nating in a mine in northeastern Montana (Swenson and Shanks, 1979). Bridges served as winter 
roosts of small numbers (one to 11) of this species in the central Sierra Nevada of California (Pier¬ 
son et al., 2001). Given a paucity of observations of large numbers of these bats observed hiber¬ 
nating in caves and mines, it is possible that in some areas this species may overwinter in less con¬ 
spicuous rock crevices, as has been established for big brown bats in northern Colorado (Neubaum 
et al., 2006) and Alberta, Canada (Kliig-Baerwald et al., 2017), and as was postulated by Twente 
(1960) for some bats in Utah. 
Warm Season Roosts in Buildings, Bridges, Caves, and Mines: Long-legged myotis have 
been found roosting in buildings and bridges, caves, abandoned mines, rock crevices, and trees and 
snags during warmer months. A maternity colony of about 500 bats was reported in crevices 
beneath the roof at old Fort Tejon on the slopes of the Tehachapi Mountains in Kern County, Cal¬ 
ifornia (Dalquest and Ramage 1946), and up to 24 roosted colonially in buildings in the Jemez 
Mountains of New Mexico (Bogan et al., 1998). Bridges were found to serve as diurnal roosts of 
small numbers in the central Sierra Nevada of California (Pierson et al., 2001). These bats (pri¬ 
marily males) were found roosting in Jewel Cave in South Dakota during summer (Choate and 
Anderson, 1997). Males also predominated among mist-net captures at the mouth of Azure Cave 
at 1,361 meters elevation in Montana during September and October (Hendricks et al., 2000). Use 
of abandoned mines as maternity roosts by this species has been documented at elevations as high 
as 2,774 meters in Colorado (Navo et al., 2000) and at 2,850 meters in northern New Mexico 
(Davis and Barbour, 1970). Five used a cabin as a diurnal roost at about 2,900 meters elevation at 
Gothic, Colorado (Storz and Williams, 1996). 
Warm Season Roosts in Rock Crevices: Although roosting habits of long-legged myotis 
have been most intensively studied in forests, these bats will also roost and form maternity colonies 
in rock crevices, and individuals will switch roosts between trees and rock crevices. They have 
been observed roosting singly in scattered sandstone outcrops in spruce-fir forests at 3,500 meters 
in Colorado (Storz and Williams 1996), in groups in rock outcroppings and “hoodoos” in pon- 
derosa pine forests in northwestern Arizona and in the Jemez Mountains of New Mexico (Bogan 
et al., 1998; Herder and Jackson, 2000), and in a rock crevice in a Douglas fir-western hemlock for¬ 
est in Oregon (Ormsbee and McComb, 1998). A maternity colony of 180 was located in a crack in 
an eroded stream bank in a “practically treeless” area in the badlands of western Nebraska (Quay, 
1948:181). In the Black Hills of South Dakota, four of 10 radio-tracked bats roosted in nine rock 
crevices, including lactating females (Cryan et al., 2001). In ponderosa pine forests of the eastern 
Cascade Range in Washington and Oregon, about 15% of roosts found by radio tracking 87 adult 
females were located in 34 crevices in rock outcrops, talus slopes, or boulder fields, with 15 indi¬ 
viduals using only rock roosts or switching between rock roosts and snags; the majority of other 
roosts (72 bats) were in snags (Baker and Lacki, 2006). Nineteen pregnant or lactating females 
were radio tagged in pinon-juniper woodland or ponderosa pine forests at Mesa Verde National 
Park in southwestern Colorado, with 14 of these females successfully tracked to roosts: all roosts 
