O’SHEA, CRYAN & BOGAN: UNITED STATES BAT SPECIES OF CONCERN 
27 
Counts of hibernating Rafinesque’s big-eared bats at 10 hibemacula in caves, abandoned 
mines, and rock shelters in the Appalachian Mountains and Central Plateaus of Kentucky, North 
Carolina, and Tennessee totaled 4,100 bats, ranging from about 600 to 1,345 bats per site (Bayless 
et ah, 2011). The largest local population reported is about 1,700 bats, which utilized a group of 
abandoned mines in both winter and summer in the North Carolina part of Great Smoky Mountains 
National Park (Currie, 2000a). In southern parts of the distribution, they are found torpid less fre¬ 
quently in winter (Jones and Suttkus, 1975). An abandoned mobile home in central Florida housed 
a colony of this species year-round, but colony size was generally larger in winter (about 60 max¬ 
imum) than early summer (31 maximum; Clark, 2003). 
These bats often spend winter in other human-made structures. In southwestern Arkansas, use 
of roosts in 37 water wells was studied during winter months (October-March) over a 21-year peri¬ 
od (Sasse et ah, 2011). Most counts were of 20 or fewer bats per well, with the largest numbers (40 
or more) counted in December-February and a maximum of 103 at one well in February 2006 
(Sasse et ah, 2011). These relatively permanent structures appear to have allowed some persistence 
of the species despite loss of regional bottomland hardwoods and associated roosts, although 
counts suggest a possible declining trend (Sasse et ah, 2011). Rafinesque’s big-eared bats were 
reported hibernating in three small clusters of about 20 bats each in an open eight-meter deep cis¬ 
tern in Tennessee in 1950 (Hoffmeister and Goodpaster, 1962), a roost which had been occupied 
annually for many years previously and continued to be occupied through 1962, further suggesting 
that these bats may exhibit site fidelity to wells and cisterns at suitable locations. Bridges and build¬ 
ings were used as winter roosts in Louisiana but to a lesser extent than in summer (Jones and Sut¬ 
tkus, 1975; Ferrara and Leberg, 2005b). Only solitary bats were observed under concrete bridges 
during the colder months in the De Soto National Forest in Mississippi, whereas from one to 25 
Rafinesque’s big-eared bats (averaging four to five) were found using them during the maternity 
season (Trousdale and Beckett, 2004). Limited searches elsewhere in Mississippi found no 
Rafinesque’s big-eared bats roosting in 22 caves and 10 cisterns, but two solitary bats and one 
group of 5 were found roosting in three culverts during winter (McCartney, 2007). 
Winter Roosts in Hollow Trees: In areas without many caves and mines, Rafinesque’s big- 
eared bats winter in trees. Large, old hollow trees are used as winter roosts in Mississippi (Martin 
et ah, 2011; Fleming et ah, 2013a). In eastern Mississippi, trees with cavities used by Rafmesque’s 
big-eared bats in winter had larger girths and larger cavity volumes than trees with cavities that 
were unoccupied, but in spring trees that were selected were similar in girth and cavity size (Flem¬ 
ing et ah, 2013a). On the landscape scale, roost trees found in winter during the Mississippi study 
were at lower elevations than unoccupied trees with cavities (Fleming et ah, 2013a). Radio-tagged 
individuals roosting in hollow trees in two lakes in central Georgia during winter switched roosts 
on average every 6.9 days (range one to 22) and moved three to 210 meters between successive 
roosts (Clement and Castleberry, 2013b). Roost trees used during winter in the Georgia study were 
less likely to have low openings and were more likely to be in water tupelo trees than were unoc¬ 
cupied trees; traits of trees used as winter roosts were similar to those of trees used in summer, but 
those used in winter tended to lack elevated openings, had a narrower range of sizes, were more 
chimney-like, and had rougher interior surfaces (Clement and Castleberry, 2013b). 
Six male and six female bats were radio tracked for periods of one to 20 days in autumn and 
early winter to determine roosting habits at Upper Ouachita National Wildlife Refuge in north¬ 
eastern Louisiana (Rice, 2009). Males were tracked to an average of 2.2 roosts, spending 4.4 days 
per tree (up to 11 days), and traveling an average of 177 meters between roosts, whereas females 
used an average of 1.7 roosts and spent 2.8 days per roost (up to six days), traveling an average of 
291 meters between roosts (up to 1,726 meters). As in the Georgia study, an important finding in 
