O’SHEA, CRYAN & BOGAN: UNITED STATES BAT SPECIES OF CONCERN 
7 
ticularly as new molecular genetic studies of evolutionary relationships continue to cause refine¬ 
ments in systematic treatments of bats. This section also provides the reader with other common 
names found in the literature, as well as interesting information about the etymology (Latin or 
Greek meanings) of the scientific name or about the person for whom a species might be named 
(patronym or eponym; for example, Townsend, Leib, and others). 
The section on Habitats and Relative Abundance gives details regarding habitats utilized 
by the species (Roosting Habits are provided in a separate section, see below). The description 
of habitats utilized includes general information on elevations, physiographic and geologic fea¬ 
tures, and vegetation types as studied in various parts of the species distribution. For ease of navi¬ 
gation by the reader, this section is usually hierarchically organized by geographic regions and then 
state or province. Although there are many ecological classifications of vegetation zones available, 
we limit our use to general categorizations or those provided by original authors, and recommend 
that readers consult the original works as well as recent sources on vegetation classification 
schemes for greater details. This section also provides findings on the relative abundance of species 
of concern as available from published bat community surveys using mist nets or in some cases 
echolocation detectors. Information on relative abundance of wildlife in general can be difficult 
and sometimes inappropriate to evaluate (for example, Anderson, 2001), and inferences in the case 
of bats should be strongly qualified by the many known (and perhaps many still unknown) biases 
inherent in such surveys. 
Biases associated with capture surveys can include the availability of preferred roosting sites 
in an area; the basis for capture data (such as mist nets, harp traps, echolocation detectors, and their 
placement); species differences in maneuverability and susceptibility to capture (which with mist 
netting may vary according to the availability of water for drinking or with body mass when preg¬ 
nant); or investigator bias when seeking out particular species while conducting surveys. Biases 
associated with acoustic surveys include differences in intensity, detectability, and uniqueness of 
echolocation pulses among species and an inability to count individual bats. Nonetheless, more 
accurate and precise methods for estimating true abundance of bats have been elusive (O’Shea and 
Bogan, 2003; Loeb et al., 2015). We therefore include information about relative abundance from 
surveys because it may have utility in qualitatively judging the possible rarity or commonness of a 
particular species of concern in surveyed habitats, landscapes, or regions of specific interest. It may 
also help guide future research efforts on habitat use by bats. The reader should also bear in mind 
that species abundances in bat community surveys follow general, often log-normal, patterns seen 
in many other biotic communities (Magurran, 2004). These patterns often consist of many indi¬ 
viduals of a few co mm on species, with fewer individuals distributed with decreasing frequency 
across a larger number of less common species (for additional background on patterns of diversity 
and abundance in bats see Kingston, 2009). Due to the sparse or geographically variable nature of 
habitat and relative abundance information available on most bat species of concern, we refrain 
from generalizing prior observations through tabulation or other types of synthesis. Instead most 
observations are presented in narrative form, with the hope that consistent patterns eventually will 
take shape and encourage the scientifically vital next steps of hypothesis formulation and testing 
regarding causal factors affecting differential use of habitats by bats. 
The section on Foraging and Dietary Analysis summarizes published observations and 
more rigorous research (where available) on the foraging habits of each species, including dietary 
components ascertained through analyses of feces or stomach contents. 
The section Roosting Habits summarizes current knowledge on general roosting habits, 
winter roosts, warm season roosts, night roosts, and other aspects of each species’ roosting ecolo¬ 
gy. Different species of bats can be very specialized or generalized in their choice of roosts, but 
