Myotis Evotis Research Articles

Sampling Duration and Season Recommendations for Passive Acoustic Monitoring of Bats after White-Nose Syndrome

Abstract Since 2006, white-nose syndrome has caused drastic declines in populations of several hibernating bat species throughout eastern North America. Thus, there is a growing need to establish long-term monitoring programs to assess changes in bat populations over time. Information on the seasonal timing of species occurrence and the sampling effort required to acoustically detect individual bat species and obtain complete inventories will enable researchers to design and implement more effective monitoring programs. From April to October 2018 to 2021, we passively sampled for bats using full-spectrum detectors at eight permanent sites at Fort Indiantown Gap National Guard Training Center, Pennsylvania. We examined seasonal activity patterns and estimated bat species richness among sites and seasons using species accumulation curves. We also estimated probability of detection (p) and site occupancy (Ψ) using single-season occupancy models in PRESENCE software and then determined the minimum number of sampling nights needed to reliably infer the absence of each species. We identified 286,131 bat passes of eight species in 4,107 detector-nights. Seasonal patterns of activity varied among species. We needed approximately 20 sampling nights to detect 90% of the total bat species richness among sites, and we needed 4 to 10 nights to detect 90% of species richness among seasons. We needed relatively few nights (≤12 nights) to detect most species during summer; however, we needed many more nights to detect acoustically rare species. Our results indicate that the acoustic sampling effort currently required to determine the presence or probable absence of Indiana myotis Myotis sodalis, northern long-eared myotis M. septentrionalis, and tricolored bats Perimyotis subflavus during summer may not be adequate for these species in some areas and that a considerable level of effort (>40 nights) is needed to detect little brown myotis M. lucifugus. Monitoring programs that incorporate efficient sampling methodologies will be critical for future conservation efforts as populations of several bat species continue to decline.

NEW RECORDS ABOUT THE DIVERSITY, DISTRIBUTION, AND SEASONAL ACTIVITY PATTERNS BY BATS IN YUKON AND NORTHWESTERN BRITISH COLUMBIA

The bat fauna of northwestern Canada remains poorly known, principally owing to a lack of dedicated surveys across this vast region. To better assess the diversity of bats in the region, we compiled records from several acoustic survey projects and capture sessions whose purpose was to inventory bats in Yukon and northwestern British Columbia (BC) from 2013 to 2018. During our surveys we obtained the 1st apparent acoustic records for Yuma Myotis (Myotis yumanensis), Californian Myotis (M. californicus), Long-eared Myotis (M. evotis), Silver-haired Bat (Lasionycteris noctivagans) and Eastern Red Bat (Lasiurus borealis) from this region. We also captured 2 Long-eared Myotis in northwestern BC. Additionally, our surveys provided range extensions of Northern Myotis (M. septentrionalis), Long-legged Myotis (M. volans), and Hoary Bat (Lasiurus cinereus). Finally, by deploying bat detectors in late autumn, and in some cases throughout the winter, we provide data about seasonal patterns for bat activity in some locations, revealing that bats in northwestern BC may be active as late as 29 October and emerge as early as 30 March, a pattern similar to that observed in southern BC. By combining data from several disparate surveys, conducted for different reasons by different researchers, we were able to provide a fuller picture of the bat fauna of this vast region. Our data provides further evidence that the bat fauna of northwestern Canada is richer than previously documented.

COAT COLOR OF WESTERN LONG-EARED BATS (MYOTIS EVOTIS) LIVING IN DIFFERENT ENVIRONMENTS: A TEST OF GLOGER'S RULE

Gloger's rule is an ecogeographical pattern observed in many vertebrates whereby populations in more humid environments have darker pigmentation than populations in more arid environments. The coat color for several species of temperate bats exhibits this pattern, including the Western Long-eared Bat (Myotis evotis) in coastal versus interior populations. We tested Gloger's rule by comparing the coat of M. evotis in the mountains and prairies of Alberta, areas with similar humidity. We predicted that both sets of bats would have similar pigmentation if humidity is the main factor driving variation in coat coloration. Discriminant function analysis of color attributes readily separated M. evotis in the mountains from those in the prairies. Individuals were darker in the mountains, violating Gloger's rule. Differential selection by nocturnal predators against conspicuous coat may explain the color differences we found, and perhaps in other species of temperate bats.

Decline of the Northern Long-Eared Myotis (Myotis septentrionalis) in the Eastern Great Plains After the Arrival of White-Nose Syndrome

The northern long-eared myotis (Myotis septentrionalis) has declined sharply in the eastern United States due to the disease white-nose syndrome (WNS), which is caused by the fungus Pseudogymnoascus destructans (Pd). However, less is known about the species' status in the central and western parts of its range where WNS has arrived more recently. Here we report the timing of the arrival of Pd and WNS to eastern Nebraska and examine acoustic and capture data of M. septentrionalis to determine the initial impact of the disease on this species. We sampled bats for the presence of Pd and WNS at several mines and one rock crevice in eastern Nebraska from 2014 to 2017. We also recorded bats with acoustic detectors and captured bats with mist nets in spring and summer from 2014 to 2019 at 2 forested sites along the Missouri River near areas of sampling for Pd/WNS. Both acoustic and capture data suggested that M. septentrionalis went from a common species in forests of eastern Nebraska to one that is encountered rarely after the arrival of WNS. Similar to the population declines in the eastern United States, our observations indicate that M. septentrionalis has also declined steeply in the eastern Great Plains and should be closely monitored in western parts of its distribution as WNS continues to spread.

Spatial Gaussian processes improve multi‐species occupancy models when range boundaries are uncertain and nonoverlapping

Abstract Species distribution models enable practitioners to analyze large datasets of encounter records and make predictions about species occurrence at unsurveyed locations. In omnibus surveys that record data on multiple species simultaneously, species ranges are often nonoverlapping and misaligned with the administrative unit defining the spatial domain of interest (e.g., a state or province). Consequently, some species display differentially restricted extents within a study area. Assuming hard boundaries based on expert opinion or published range maps to restrict species occurrence predictions implies a false sense of certainty in model‐based inferences. We propose a multi‐species occupancy model with a spatial Gaussian process on site‐specific effects for each species as a model‐based solution. Specifying informative Bayesian hyperpriors on the spatial hyperparameters encapsulates broad‐scale correlation among site occupancy probabilities for each species. We fit this model to acoustic detection/nondetection data collected with autonomous recording units during summer of 2016–2019 throughout Oregon and Washington, USA, on 15 bat species. We found vast improvements in spatial predictions of spotted bat (Euderma maculatum), canyon bat (Parastrellus hesperus), and Brazilian free‐tailed bat (Tadarida brasiliensis) when the available environmental predictors were insufficient for characterizing their restricted ranges within the region. In contrast, widespread species (Lasionycteris noctivagans, Myotis californicus, Myotis evotis, Myotis volans) were appropriately modeled using only environmental predictors, such as percentage forest cover and cliff and canyon cover. Utilizing spatial Gaussian processes within a community or multi‐species model incorporates uncertainty in range boundaries and allows for simultaneous predictions for the entire faunal assemblage even if species have nonoverlapping or restricted ranges within a spatial domain of interest. Such modeling improvements are essential if species distribution models are to accurately inform monitoring, species recovery plans, and other conservation efforts.

Reply to the comment by Morales et al. on “Population genetics reveal Myotis keenii (Keen’s myotis) and Myotis evotis (long-eared myotis) to be a single species”

A.E. Morales et al. (2021. Can. J. Zool. 99(5): 415–422) provided no new evidence to alter the conclusions of C.L. Lausen et al. (2019. Can. J. Zool. 97(3): 267–279). We present background information, relevant comparisons, and clarification of analyses to further strengthen our conclusions. The genesis of the original “evotis–keenii” study in British Columbia (Canada) was to differentiate Myotis keenii (Merriam, 1895) (Keen’s myotis), with one of the smallest North American bat distributions, from sympatric Myotis evotis (H. Allen, 1864) (long-eared myotis), using something other than the suggested post-mortem skull size comparison, but no differentiating trait could be found, leading to the molecular genetics examination of C.L. Lausen et al. (2019). We present cumulative data that rejects the 1979 hypothesis of M. keenii as a distinct species. A.E. Morales et al. (2021) inaccurately portray C.L. Lausen et al.’s (2019) question and results; present inaccurate morphological and outdated distribution data; overstate the impact of homoplasy without supporting evidence; and misinterpret evidence of population structure.

Comment on “Population genetics reveal Myotis keenii (Keen’s myotis) and Myotis evotis (long-eared myotis) to be a single species”

Genetic exchange and hybridization appear common among the western long-eared bats from North America. Multiple sources of evidence indicate that lineages within this group are evolving independently, despite genetic exchange. However, evidence of gene flow raises questions about the species-level status of some lineages. C.L. Lausen et al. (2019. Can. J. Zool. 97(3): 267–279) proposed that Myotis evotis (H. Allen, 1864) (long-eared myotis) and Myotis keenii (Merriam, 1895) (Keen’s myotis) are one species, not two. This conclusion is based on analyses of cytochrome b and microsatellite data suggesting gene flow between these taxa. Microsatellites are not reliable markers for identifying species because homoplasy can be a major confounding factor, which appears to be true in this case. We reanalyzed the dataset of C.L. Lausen et al. (2019) and show that it is not reliable to distinguish between gene flow or homoplasy, and that these data do not support the conclusion that M. evotis and M. keenii represent a single species. Previous morphological and genomic studies indicate that these are separate species despite previous genetic exchange between them. Failing to recognize that gene flow can occur between independently evolving lineages is counterproductive for conservation because it can lead to neglect of important independent lineages, and likewise failing to use proper tools to delimit species is counterproductive to efforts to quantify biodiversity and design conservation strategies.

Bats (Chiroptera) of Glen Canyon National Recreation Area, Utah and Arizona

Glen Canyon National Recreation Area covers large and geographically unique regions of southern Utah and northern Arizona. However, multiple surveys of bats from 1952 to 2017 have not been published. Prior to 2015, most bat surveys in the recreation area were conducted using mist nets only and did not include acoustic monitoring. In this paper we compile records of bats found in Glen Canyon National Recreation Area from 1952 to 2017, including records from our recent surveys using both mist nets and acoustic sampling. During our recent surveys, 2 new species were captured (Nyctinomops macrotis and Lasionycteris noctivagans), and 2 other new species were documented using acoustic detection (Myotis evotis and Eumops perotis), bringing the total documented bat species in Glen Canyon National Recreation Area to 17 species. This paper sheds light on the diverse bat assemblage of Glen Canyon National Recreation Area that will serve as a baseline for future research and conservation efforts.

Consumption of spiders by the little brown bat (Myotis lucifugus) and the long-eared myotis (Myotis evotis) in the Rocky Mountains of Alberta, Canada

Intraspecific variation in diet and (or) foraging behaviour is one way in which species are able to occupy wide geographical areas with variable environments. The little brown bat (Myotis lucifugus (Le Conte, 1831)), a primarily aerial insectivorous bat, consumes spiders in low temperatures at the start and end of summer in Northwest Territories, Canada, but it consumes spiders all summer, even during high aerial insect abundance, in Alaska, USA. There are no competitors of M. lucifugus in Alaska, but there are in Northwest Territories, suggesting that aerial insect abundance and competition from gleaning bats influences when M. lucifugus consumes spiders. In the Kananaskis area of the Rocky Mountains of Alberta, Canada, we investigated spider consumption by M. lucifugus and the long-eared myotis (Myotis evotis (H. Allen, 1864)), a species more adept at gleaning, to better understand when bats consume spiders. Fecal sample analysis indicated that M. evotis consumed spiders all season long, with greater consumption when the bats were caught near water. Myotis lucifugus did not consume spiders at all. This suggests that M. lucifugus opportunistically consumes spiders when encountered, but does not encounter them in Kananaskis where it forages primarily over open water, unlike in Northwest Territories where it forages in the interior of forests and may encounter spiders more frequently.

Winter Use of a Rock Crevice by Northern Long-Eared Myotis (Myotis septentrionalis) in Nebraska

We used a combination of acoustic detectors, thermal imaging cameras, and mist netting to confirm the use of a rock crevice by northern long-eared myotis (Myotis septentrionalis) in winter in northeastern Nebraska. Bats roosted in a large crevice in a rock face along the Missouri River, and 5 individuals were captured emerging from the opening of the crevice in March 2017. Our study is the first to confirm the use of a rock-crevice hibernaculum by M. septentrionalis and adds to the growing literature on the winter use of rock crevices by hibernating bats in North America. As white-nose syndrome (WNS) continues to spread across North America and decimate populations of M. septentrionalis, more knowledge of hibernation requirements is necessary to develop an effective recovery plan and to monitor this threatened species.

Acoustic Surveys for Bats are Improved by Taking Habitat Type into Account

ABSTRACTPassive monitoring of bat species via acoustics is a growing field and as a result there are various software programs available that allow for species identification. However, accuracy of these programs is variable and creating a local call library is essential when trying to identify acoustically similar species. In Dinosaur Provincial Park, Alberta, Canada, 3 Myotis species are difficult to distinguish acoustically. We created an echolocation call library from known Myotis evotis, M. lucifugus, and M. ciliolabrum flying in open spaces and near clutter to test whether or not recording in the bats' local habitat type improved call library quality and identification accuracy. Bat calls recorded within open spaces (coulees) differed from those recorded near cluttered spaces (tree edges) for M. ciliolabrum and M. lucifugus. Accuracy of species identification also increased when we used models based on bat calls recorded in cluttered habitats. Using a simple model with recordings from different habitat types within a study site, we were able to improve identification accuracy and model performance. © 2019 The Wildlife Society.

Variation in Reproductive Timing for the Northern Long-Eared Myotis (Myotis septentrionalis) Across Nebraska

The northern long-eared myotis (Myotis septentrionalis), a federally threatened species, occurs in extreme northern, eastern, and southern Nebraska. These regions vary in climate due to geographic location, topography, and elevation. During a 1-week period in early July 2015, we surveyed bats across the state and observed striking variation in the reproductive status for M. septentrionalis. We examined whether or not growing degree days, an abiotic climatic factor used mainly for agricultural practices, was associated with this reproductive variation in a mammalian species. In early July, we captured only pregnant females in the Pine Ridge region of northwestern Nebraska, the region with the lowest number of growing degree days. In contrast, we captured both lactating females and flying young along the Republican River in south-central Nebraska near the border with Kansas, an area with a high, but intermediate number of growing degree days. Along the Missouri River, in extreme east-central Nebraska, along the border with Iowa, we documented lactating females with no evidence of volant young. This locality had the highest number of growing degree days. Phenotypic plasticity in timing of births for M. septentrionalis appears to be, in part, related to climatic differences across Nebraska, a relationship commonly observed for plants and invertebrates. Our study demonstrates that reproductive phenology can vary significantly across the distribution of a species and needs to be considered when making management decisions for imperiled species. Delayed reproduction in cooler regions of the species' range presents risks to reproductive female M. septentrionalis and their nonvolant offspring, even with current protective measures. In areas with short growing seasons, restrictions on the timing of tree-cutting should be expanded beyond 31 July in more northerly parts of the species' distribution, so as not to hinder reproductive success during the time when juvenile bats are unable to fly.

Changes in a summer bat community in southeastern Pennsylvania

Abstract Bat population changes are poorly understood, making it difficult to establish management priorities. In 2017, a summer mist-netting survey previously conducted in 2004 at Fort Indiantown Gap was replicated to evaluate temporal changes in the local bat community. The authors hypothesized that captures of species most affected by white-nose syndrome (WNS) would decline between survey periods, and that community structure would shift. The results showed a 100% decline in captures of northern long-eared Myotis (Myotis septentrionalis) and little brown Myotis (M. lucifugus), no change in captures of eastern red bats (Lasiurus borealis), a 276% increase in captures of big brown bats (Eptesicus fuscus), and a considerable shift in community structure. These results are consistent with expected effects of WNS on Myotis populations. Increases in big brown bat populations may result from ecological release after the decline of Myotis species, or from local or large-scale habitat change over time.

Population genetics revealMyotis keenii(Keen’s myotis) andMyotis evotis(long-eared myotis) to be a single species

Recognizing delineations of gene flow among groups of animals can be challenging but is necessary for conservation and management. Of particular importance is the identification of species boundaries. Several physical and genetic traits have been used with mixed success to distinguish Myotis keenii (Merriam, 1895) (Keen’s myotis) and Myotis evotis (H. Allen, 1864) (long-eared myotis), but it is unclear whether species distinction is biologically warranted. We generated 12–14 microsatellite locus genotypes for 275 long-eared Myotis representing four species — M. keenii, M. evotis, Myotis septentrionalis (Trouessart, 1897) (northern myotis), and Myotis thysanodes Miller, 1897 (fringed myotis) — from across northwestern North America and 23 Myotis lucifugus (Le Conte, 1831) (little brown myotis) as the outgroup. Population genetic analyses revealed four well-defined groups (species): M. septentrionalis, M. thysanodes, M. lucifugus, and a single group comprising M. keenii and M. evotis. We document high rates of gene flow within M. evotis/M. keenii. Cytochrome b gene (mtDNA) sequencing failed to resolve morphologically identifiable species. We highlight the importance of geographically thorough investigation of genetic connectivity (nuclear markers) when assessing taxonomic status of closely related groups. We document a morphometric cline within M. evotis/M. keenii that may in part explain earlier analyses that led to the description of the smaller bodied M. keenii (type locality: Haida Gwaii). We conclude that M. keenii does not qualify as a genetic or biological species.

Bat species distribution and habitat associations in northern Ontario, Canada

Bats are facing threats from disease, wind power development, and climate change, which are causing populations of many species to decline. The northern range limits of many temperate species are not well characterized, but the true distribution of threatened bat species is critical information for their conservation. We used passive acoustic monitoring and false-positive occupancy models to estimate the distributions of six species of bats in northern Ontario (north of ca. 50.5°N). We confirmed the presence of big brown bats (Eptesicus fuscus), hoary bats (Lasiurus cinereus), eastern red bats (Lasiurus borealis), silver-haired bats (Lasionycteris noctivagans), little brown myotis (Myotis lucifugus), northern long-eared myotis (Myotis septentrionalis), and tri-colored bats (Perimyotis subflavus) in our study area. We found that big brown bats, hoary bats, and little brown myotis likely are more widespread and common in northern Ontario than previously thought. Our models also provided evidence of associations between temperature and habitat types and bat occupancy probabilities. Our occupancy probability maps for each species support bat conservation by providing much finer-scale distribution information than previously available. These results provide a much-needed baseline for future studies of the distribution of these bat species in northern Ontario against which to measure the effects of white-nose syndrome, resource development, and climate change.

Resource selection and space use ofMyotis evotisin a western juniper woodland in Oregon

Resource selection models and estimates of home range provide land managers with information that is required to make informed decisions regarding wildlife conservation and management across multiple spatial scales. We used radiotelemetry to examine resource selection and space use of Myotis evotis (western long-eared myotis) in a western juniper (Juniperus occidentalis) woodland in eastern Oregon, United States. Small sample sizes likely constrained our ability to detect differences between estimates of home range size for males (x = 424.2 ha, SE = 187.2) and lactating females (x = 205.85 ha, SE = 47.94). Our estimates are among the largest reported for Myotis species, but likely are biased low due to low ambient temperatures and the methods we used to estimate home range. Best resource selection models for males and lactating females differed across spatial scales, based on Akaike's information criteria with a bias correction term for small sample size (AICc). At the home range scale, resource use by lactating females was negatively related with distance from water, whereas males selected areas with > 0–10% canopy cover over areas with no canopy cover. At the landscape scale, resource use by males and lactating females decreased with increasing distance from roosts and water sources. Additionally, lactating females avoided areas with > 20% canopy cover more than areas with no canopy cover. These results emphasize the importance of managing pre-settlement woodlands located near roost sites and water sources for variable tree densities to maintain foraging areas for bats.

Shifts in Assemblage of Foraging Bats at Mammoth Cave National Park following Arrival of White-nose Syndrome

The arrival of white-nose syndrome (WNS) to North America in 2006, and the subsequent decline in populations of cave-hibernating bats have potential long-term implications for communities of forest-dwelling bats in affected regions. Severe declines in wintering populations of bats should lead to concomitant shifts in the composition and relative abundance of species during the staging, maternity, and swarming seasons in nearby forested habitats. We examined capture rates of bats collected in mist nets from 2009 to 2016 to evaluate summer patterns in abundance of species pre- and post-arrival of WNS to Mammoth Cave National Park, KY. The data demonstrated a significant change in overall relative abundances. Myotis septentrionalis (Northern Long-eared Myotis) was the most commonly captured species pre-WNS but declined to 18.5% of its original abundance. Nycticeius humeralis (Evening Bat), uncommonly caught in mist nets pre-WNS, demonstrated the largest increase in capture success following arrival of WNS to the Park, followed by Eptesicus fuscus (Big Brown Bat) and Lasiurus borealis (Eastern Red Bat). These data suggest that losses of cave-hibernating bats to WNS may be leading to a restructuring of foraging bat assemblages in nearby forested habitats, with species less affected by WNS potentially exploiting niche space vacated by bats succumbing to infection with WNS.

Night-Roosting Behaviors for the Northern Long-Eared Myotis (Myotis septentrionalis) Under a Bridge Revealed by Time-Lapse Photography

The northern long-eared myotis (Myotis septentrionalis) occurs across much of eastern North America and is listed as federally threatened in the United States due to pervasive population declines. Limited data are available about roosting behaviors for this imperiled species. We report on night-roosting behaviors for the northern long-eared myotis under a bridge in northwestern Nebraska. Grooming, short visits, and feeding were the most frequently observed behaviors. Grooming, inactivity, and nursing had the longest durations, albeit all averaged <15 min per event. We also documented movement and urination infrequently. Prey manipulation associated with feeding was a frequent behavior and consisted of individuals facing upward or downward, culling wings, elytra, and legs of large prey items. When facing upward wing and tail membranes formed a cup against the abutment wall that likely limited loss of prey. Individuals used the bridge throughout the night but roosted most frequently at 4 and 8 h after sunset (00:15 and 04:15 h, respectively), with early morning activity dominated by feeding/prey manipulation. Our study showed night roosts were used frequently for many reasons, especially for grooming and consumption of large prey. Our observations represent the first description of night-roosting behaviors for the northern long-eared myotis.

Roost site selection of western long‐eared myotis in a western juniper woodland

ABSTRACTSeveral bat species occur in piñon (Pinus monophylla) and juniper (Juniperus ssp.) woodlands across the western United States, yet factors influencing roost site selection in these vegetation communities are poorly understood. Piñon‐juniper woodlands have expanded beyond their historical geographic range in the western United States since European settlement. Many former stands of widely spaced old‐growth juniper are now crowded with younger trees. Currently, federal and state land management agencies and private landowners are removing juniper trees to restore shrub‐steppe for greater sage‐grouse (Centrocercus urophasianus) across its geographic range, with little understanding of the treatment effects on roost site selection by bats. We used radio‐telemetry to examine roost site selection of western long‐eared myotis (Myotis evotis) at 3 spatial scales (roost, plot, and home range) during the breeding season. We attached radio‐transmitters to 32 individuals and located 92 day roost sites for 25 different individuals. Lactating females selected rock crevices as roosts more frequently than tree cavities, whereas males used tree roosts and rock roosts more evenly. The majority of tree roosts were in pre‐settlement trees that had at least 1 cavity. The odds that a tree was selected as a roost site increased with the number of available tree roosts within 17.8 m of the roost site. Preference by lactating females for rock roost sites increased with the number of available rock roosts within 5 m of the roost site and decreased with distance from water. Preference by males for rock roosts decreased if the roost was a single rock compared to an aggregate of rocks, increased with the number of available roosts within 5 m of the roost site, decreased with distance from water, and increased with area of pre‐settlement juniper woodland within 1 km of the roost site. These results provide support for protecting pre‐settlement juniper trees and rock formations near water sources in juniper woodlands to conserve existing populations of western long‐eared myotis during the breeding season. © 2018 The Wildlife Society.

Identification of Southeastern Bat Species Using Noninvasive Genetic Sampling of Individual Guano Pellets

Abstract The impact of white-nose syndrome on North American bat populations may limit the effectiveness of traditional monitoring methods, including roost surveys, mist netting, and acoustic monitoring, and, in turn, determination of bat species occurrence. Genetic markers from deoxyribonucleic acid (DNA) extracted from feces (i.e., guano pellets) may provide an effective alternative method for assessing occurrence. We used an existing genetic marker from the 16S ribosomal subunit, mitochondrial DNA, to create a DNA sequence database for the 16 species of bats known to occur in Tennessee. We used our database to identify bat species from DNA extracted from 68 guano pellets collected from accumulations found in buildings of Great Smoky Mountains National Park from May to August 2015. No bats were directly observed at 19 roost buildings (55.9% of all identified roost buildings), where genetic analysis of guano was the only method available to determine species occurrence. Two of the species we detected roosting in buildings using DNA from guano, the little brown myotis Myotis lucifugus and northern long-eared myotis M. septentrionalis, are of special concern as a result of declines from white-nose syndrome. There are no records of the northern long-eared myotis roosting in Great Smoky Mountains National Park buildings, and no records of the little brown myotis roosting in buildings since white-nose syndrome became established in Great Smoky Mountains National Park. Our findings emphasize the utility of these genetic techniques for detecting bat species when visual or acoustic methods may be compromised by species rarity, elusive behavior, or similarities in species morphology and call characteristics.