52 
PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES 
Series 4, Volume 65, Supplement I 
ed in species of Myotis inhabiting several caves also used by apparently unaffected eastern sub¬ 
species of Townsend’s big-eared bat (Johnson et al., 2012b), it was not until 2017 that an individ¬ 
ual of this species in Texas tested positive for P. destructans (no mortality or clinical signs of dis¬ 
ease were observed; Texas Parks and Wildlife, 2017). Hamm et al. (2017) discovered actinobacte- 
ria (including Streptomyces ) with anti-fungal properties on wings of these bats and postulated that 
actinobacteria may have defensive properties against the fungus that causes white-nose syndrome 
as it moves into western North America. 
A hibemaculum in New Mexico that housed more than 10,000 Townsend’s big-eared bats in 
1992 had been set afire by vandals the same winter, with hundreds of carcasses evident and thou¬ 
sands presumed dead (Pierson and Rainey, 1998a; Pierson et al., 1999). 
Population Trend: There has been considerable interest in the population status of the west¬ 
ern subspecies of Townsend’s big-eared bat over the past 25 years, resulting in a number of efforts 
to document colony sizes at hibemacula and maternity roosts (Ellison et al., 2003). One recent 
analysis has shown that some of these surveys can be useful for inference about local population 
trends (Weller et al., 2014; see below). Compilations of other data sets in the past, however, showed 
limitations to analysis of independently documented survey data. Ellison et al. (2003) showed that 
only 15 hibemacula and six summer colonies of the western subspecies that they had obtained 
included four or more separate years of records available for analyses. Statistically significant non- 
parametric trends were undetectable for 12 of the 15 hibemacula, with one of the remaining three 
increasing and two declining; similarly, trends were not detectable in five of six summer colonies, 
with one showing a significant decline (Ellison et al., 2003). The population in the hibemaculum 
at Jewel Cave National Monument declined from about 3,750 in 1959 to 853 in winter 2000 (Elli¬ 
son et al., 2003), with a marked drop from 1959 to 1967 when much banding of bats was conducted 
(Choate and Anderson, 1997). Banding injuries and disturbance of several species of bats probably 
contributed significantly to increased mortality during the era of large-scale bat banding activities 
(for reviews see O’Shea et al., 2004; Ellison, 2008). Prendergast et al. (2010) analyzed trends in 
counts of Townsend’s big-eared bats made at 10 hibemacula in gypsum caves in Kansas and Okla¬ 
homa, also using a non-parametric statistical approach. Counts were made intermittently during 
1965-2004, ranging from 0 to 235 individuals over the course of five to 11 annual surveys. No 
trend was detectable in counts at eight hibemacula, with one colony showing a decrease and one 
showing an increase (Prendergast et al., 2010). 
Although limitations to most trend analyses were apparent from independently acquired post 
hoc count data sets for Townsend’s big-eared bats in the western U.S., Weller et al. (2014) provid¬ 
ed a good recent example of how such data nonetheless can be usefully applied to make inferences 
about local population trends. They compiled winter count data from 52 of 97 caves surveyed over 
the period 1991-2012 at Lava Beds National Monument in northern California. They used log-lin¬ 
ear models following a negative binomial distribution to estimate slopes of trend lines over time 
and to predict future counts. Seventeen of 22 (77%) caves that had four or more years of count data 
showed positive trends, with counts in these more-frequently surveyed caves having an annual 
growth rate of about 4% (Weller et al., 2014). Combined estimated counts at all caves increased 
from 834 bats in 1991 to 1,427 in 2012, with an estimated positive annual growth rate of 1.8% dur¬ 
ing the period. The positive growth rates coincided with the implementation of more restrictive 
human visitation regulations (Weller et al., 2014). However, as Weller et al. (2014) point out, infer¬ 
ences apply only to their sample and overall trends at the approximately 750 caves at Lava Beds 
National Monument remain unknown. 
Although there are few similar statistical analyses of trends in population sizes, most other 
available information on changes in populations of the subspecies C. townsendii townsendii or 
