O’SHEA, CRYAN & BOGAN: UNITED STATES BAT SPECIES OF CONCERN 
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was suspected based on positive genetic tests on white-crustal growth sampled from the wings of 
a single bat in 2010 (Brennan et al., 2015). Cave myotis were sampled each winter at caves in west¬ 
ern Oklahoma for the subsequent four years, but no field evidence of the disease was found, and 
re-testing of the bat examined in 2010 was found to be negative for presence of the white-nose syn¬ 
drome fungus (Brennan et al., 2015). Antibodies to other fungal agents were detected in blood of 
13 of 28 individuals from the region, but evidence for specific exposure to P. destructans could not 
be conclusively demonstrated (Brennan et al., 2015). Similarly, 83 soil samples from about 17 
caves used as hibemacula across Oklahoma were negative for evidence of this fungus (Creecy et 
al., 2015). However, white-nose syndrome was confirmed in a tri-colored bat in eastern Oklahoma 
during April of 2017 (Oklahoma Department of Wildlife Conservation, 2017) and DNA of the fun¬ 
gus P. destructans was genetically detected on three species of hibernating bats, including a cave 
myotis, in Texas during 2017 (Texas Parks and Wildlife Department, 2017). Hamm et al. (2017) 
discovered actinobacteria (including Streptomyces ) with anti-fungal properties on wings of this 
species and postulated that actinobacteria may have defensive properties against the fungus that 
causes white-nose syndrome as it moves into western North America. 
Population Trend: Counts made from 1965 to 2004 at 11 hibemacula in the Red Hills of 
south-central Kansas and northern Oklahoma suggested one colony in decline, three increasing, 
and seven with no statistically detectable change; count estimates per hibemaculum ranged from 
zero to 26,500 bats (Prendergast et al., 2010). Ellison et al. (2003) analyzed time-series data for one 
summer colony and five hibernating colonies that included counts in four or more separate years 
in four states (Kansas, Arizona, New Mexico, and Texas). Counts at two winter colonies in Texas 
declined in the 1950s and 1960s, whereas the other colonies showed no significant trends (Ellison 
et al., 2003). In one study at a cave in Texas, Elliott et al. (2006) reported that estimates made by 
counting numbers of cave myotis with a stopwatch during emergence in comparison with estimates 
made based on ceiling-areas occupied and density of roosting bats were within 13% of each other. 
Although more recent population estimates are not available, knowledge from local areas in 
California, Nevada, and Arizona suggests decline (Altenbach and Pierson, 1995; Pierson et al., 
1991; O’Shea and Vaughan, 1999; Brown, 2013). Possible movements of colonies to alternate loca¬ 
tions were not investigated. However, considerable numbers of bats had been banded at some of 
these sites, and banding is known to contribute to declines in some bat populations (O’Shea et al., 
2004). In the Verde Valley of central Arizona, a colony of about 5,000 individuals present in sum¬ 
mer 1972 was absent in 1997, with the absence attributed to increased use of the area by recre¬ 
ationists (O’Shea and Vaughan, 1999). In southern Arizona, Hayward (1961, 1970) reported large 
reductions at warm-season colonies in three mines, thought to be due to disturbance, including a 
drop from 20,000 in 1953 to 200 in 1959 at a single site. The only known colony of this species in 
Nevada, about 70 bats including females, was discovered in a mine in 1961 (Cockrum and Mus- 
grove, 1964b); only 12 were seen in 2001 (Brown, 2013). Four abandoned mines in the Riverside 
Mountains of the lower Colorado River Valley in California known to have maternity colonies 
numbering in the thousands during the 1930s-1950s (Stager, 1939; Vaughan, 1959) were revisited 
during the 2000s and only two were found to have maternity colonies, with numbers present much 
lower than earlier estimates (Brown, 2013). 
Contemporary published estimates of range-wide population size are unavailable. However, 
there are published rough estimates for various regions and colonies made in past decades that 
would provide useful comparisons should future characterizations of population size and trends be 
made. Hoffmeister and Goodpaster (1954) reported a colony of about 10,000 cave myotis in sum¬ 
mer 1949 at Canelo Cave in the Huachuca Mountains of southeastern Arizona. Hayward (1961, 
1970) reported several colonies at various southern Arizona locations during the 1960s that varied 
