34 
PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES 
Series 4, Volume 65, Supplement I 
roost trees with landscape-level habitat variables. They found that colony density on eight separate 
study sites was predicted by duration of flooding, wetland width (narrower widths characterized 
deeper sloughs which favor trees with characteristics of higher use by bats), and site-specific char¬ 
acters. Over combined study sites (greater than 16,000 ha) the model estimated a mean of 3,734 
“colonies” containing an estimated 6,910 adult bats (Clement and Castleberry, 2013d). This quan¬ 
titative approach provides at the least a more optimistic outlook on the numbers of these bats that 
may exist range-wide. 
Population Genetics: Genetic diversity measures were calculated for Rafmesque’s big-eared 
bats based on mitochondrial DNA control region sequences for 360 individuals from about 31 
localities in nine states (Piaggio et al., 2011). Overall genetic diversity was high (haplotype diver¬ 
sity and to a lesser extent nucleotide diversity), and two finer-scale measures of genetic diversity 
were higher in Arkansas, Texas, and Louisiana colonies than in colonies sampled in North Caroli¬ 
na, Mississippi, and Tennessee (Piaggio et al., 2011). Genetic structuring was evident across five 
well-sampled colonies in Arkansas. Assessment of genetic diversity was also made for these five 
colonies based on 10 microsatellite loci. Average number of alleles per locus was 7.7 (range two to 
16); in contrast to mitochondrial DNA findings, microsatellite diversity was considered low in 
these Arkansas colonies, structuring was evident among colonies, and effective colony sizes also 
were low, but little evidence of inbreeding was detected (Piaggio et al., 2011) 
Management Practices and Concerns. — Based on population genetic assessments of 
phylogeny, management of Rafmesque’s big-eared bats based on past subspecies status (Handley, 
1959) is not recommended (Piaggio and Perkins, 2005; Piaggio et al., 2011). Consideration of man¬ 
agement actions to increase genetic connectivity among colonies in Arkansas was suggested by 
Piaggio et al. (2011). Jones (1977) regarded this species as highly susceptible to disturbance 
because of its habit of roosting in places likely to attract people, such as caves, mines, and vacant 
buildings. Forested areas and old buildings are being altered or destroyed as a result of changing 
land-use patterns, with likely negative consequences for Rafinesque’s big-eared bat in many parts 
of the southeastern U.S. (Belwood, 1992). Clark (1990) reported reduced activity and abandonment 
of roosting sites in abandoned buildings coincident with logging of adjacent forests in North Car¬ 
olina, and documented that logging made the buildings more conspicuous and thus more prone to 
disturbance and vandalism. Both reduction in bat numbers and rapid roost structure deterioration 
were noted over the course of a 14-year survey of buildings in North Carolina (Clark, 2003). How¬ 
ever, there are occasional reports of colonies persisting in bams that were actively used by people 
(Clark, 1990). 
Identification and protection of manmade structures used as roosts are important actions for 
conservation of Rafinesque’s big-eared bats (Miller et al., 2011; Lacki and Bayless, 2013). Sasse 
et al. (2011) found that multiple abandoned wells used as winter roosts in Arkansas were likely to 
be closed because of safety and environmental regulations, so they designed covers that allow bats 
to fly in and out yet block human access (Sasse and Saugey, 2014). Lance et al. (2001) found that 
the older concrete bridges with girders selected as day roosts by Rafmesque’s big-eared bat in the 
Kisatchie National Forest in Louisiana are being replaced by concrete bridges with flat bottoms. 
This type of constmction is not favored by this species for roosts; therefore Lance et al. (2001) sug¬ 
gested that the replacement bridges could be modified with the addition of stmctures that would 
provide secure roosts. Changes in stmctures of bridges favored by Rafmesque’s big-eared bats on 
De Soto National Forest in Mississippi were also noted by Trousdale and Beckett (2004), who doc¬ 
umented occupancy of these sites by breeding females and young. They suggested that timing for 
replacement of these bridges take place outside of the maternity season. Darkness was an impor¬ 
tant factor in selection of roosting areas under bridges by these bats in Louisiana, prompting the 
