O’SHEA, CRYAN & BOGAN: UNITED STATES BAT SPECIES OF CONCERN 
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On Turnbull National Wildlife Refuge in northeastern Washington (where predominant habi¬ 
tats were ponderosa pine and Palouse zone shrub-steppeland and meadows), 14 reproductive 
females were tracked to 35 roosts and mean colony size was four bats (Rancourt et al., 2005). All 
roosts but one were located in two-centimeter-wide crevices in small isolated rocks or basalt cliffs, 
the exception being a roost under bark in a snag used for one day (Rancourt et al., 2005). Bats 
switched roosts about every two days, with an average of 149 meters between roosts. Compared to 
randomly selected plots, habitats immediately around roosts were characterized as open and rocky 
and not close to permanent water; at a 78 hectares plot size, landscapes at roosting sites were in 
areas with more grassland and aspen habitat and lower proportions of wetlands (Rancourt et al., 
2005). 
Roosting of long-eared myotis was intensively studied in both mountain and prairie habitats 
of southern Alberta, Canada (Chruszcz and Barclay, 2002, Solick and Barclay, 2006a, 2006b, 2007; 
Nixon et al., 2009). On the prairie, bats roosted most frequently in crevices in boulders and rocks 
on or near the ground and used torpor on a regular basis, with most adult females roosting solitar¬ 
ily but a few roosting in twos or threes (Chruszcz and Barclay, 2002). Females that were pregnant 
tended to occupy horizontal rock crevices and used deep torpor more often than lactating females, 
which tended to roost in vertically oriented rock crevices. These differences in crevice orientation 
presumably reflect female choice of roosts with thermal conditions suited to their particular ener¬ 
gy needs (Chruszcz and Barclay, 2002). In the Rocky Mountains of southern Alberta, they roosted 
in rock crevices (most vertically oriented) near the ground (81% were on or under the ground sur¬ 
face, with the remainder less than one meter above ground) in rock fields on south-facing slopes 
(73 of 79 roosts were in rock crevices, six were in snags), with 92% of rock roosts used just once 
(Solick and Barclay, 2006b). Each female used a roost for an average of 1.2 consecutive days, with 
average distances between roosts about 50 m. Non-reproductive females entered deep torpor more 
frequently than pregnant and lactating females. Crevices used by reproductive females tended to be 
above ground level and passively warmed more quickly than subterranean sites used by non-repro¬ 
ductive females. Pregnant females tended to roost alone, whereas lactating females were more like¬ 
ly to aggregate in roosts (mean group size of three), presumably to raise roost temperatures because 
warmer crevices were not available (Solick and Barclay, 2006b, 2007). In comparing the roosting 
ecology of this species in the mountains versus prairies of southern Alberta, Solick and Barclay 
(2007) observed that reproductive females on the prairie used torpor more frequently than their 
counterparts in the mountains and that those in the mountains tended to roost in warmer rock 
crevices exposed to the sun. More frequent use of torpor by the prairie bats may have been related 
to the longer season of favorable conditions for growth and development of young, or to the need 
to conserve water in hotter and drier conditions (Solick and Barclay, 2007). 
Bats roosting in the badlands habitat of the Red Deer River Valley in prairies of Alberta also 
switched roosts frequently, regardless of sex or reproductive status (Nixon et al., 2009). Forty-eight 
bats were tracked to 254 roosts during three summers; all but two of the roosts (one in a rock 
crevice, one in a shed) were in sheltered erosion cavities and channels in the ground on slopes of 
river and creek valleys. Regardless of sex or reproductive state nearly all bats roosted solitarily, and 
roost fidelity was low, with bats switching roosts every one to two days at distances between roosts 
ranging one to 812 meters (mean 61 m; Nixon et al., 2009). Roosts for most individuals were with¬ 
in areas less than two hectares in size, with one male’s roosting area encompassing 4.7 ha, and one 
lactating female’s roosting area only 0.08 ha; roosting areas were broadly overlapping among indi¬ 
viduals (Nixon et al., 2009). 
Warm Season Roosts in Trees, Snags, and Stumps: In addition to roosting in rock crevices 
and erosion cavities, long-eared myotis also roost in snags, stumps, and under bark of trees (for 
