Northern Long-eared Bat Research Articles

Dynamic occupancy in a peripheral population of Myotis septentrionalis during disease outbreak

ContextOnce common, the northern long-eared bat (Myotis septentrionalis) has experienced declines > 90% due to white-nose syndrome (WNS). This severe mortality has resulted in their listing under the Endangered Species Act and made them a conservation priority. However, their broad distribution, variability in habitat use, and population instability make developing range-wide conservation strategies difficult. To understand how conservation of M. septentrionalis may vary across its range, we examined shifts in M. septentrionalis site occupancy on the edge of their historic range following severe WNS mortality.ObjectivesOur goal was to determine how mortality from white-nose syndrome affects site occupancy of M. septentrionalis at the southern edge of their historic range. Understanding which areas will remain occupied during disease related mortality will help inform management during disease outbreaks.MethodsWe used 11 years (2007–2017) of mist-netting records to construct dynamic occupancy models of M. septentrionalis in northern Georgia, USA. Occupancy was updated annually, with the initial period defined as all years prior to the winter of 2012–2013, which corresponds to when white-nose syndrome entered the study area. We assessed occupancy using landscape metrics at the home range (65 ha) and landscape (491 ha) scales, year since WNS occurrence in the study area, distance to karst, and distance to nearest WNS positive county. We estimated probability of detection using Julian date and sampling effort.ResultsInitial site occupancy was positively associated with percent deciduous forest cover at the home range scale. As M. septentrionalis populations declined from WNS, a site becoming unoccupied was negatively correlated with mean contiguity of forest at the home range scale and largest patch of forest and mean elevation at the landscape scale. Site occupancy declined precipitously in the years following WNS, dropping from 70.75% (41.76–96.98% [95% CI]) occupancy pre-WNS to 0.3% (0.3–20.5% [95% CI]) by the final year of the study.ConclusionsOur results demonstrated that sites occupied by M. septentrionalis closer to the historic range edge were more vulnerable to becoming unoccupied after disease arrival. We recommend managers on the periphery of the historic range focus conservation efforts on high elevation forested areas nearer to the range core.

Importance of Manually Vetting Acoustic Bat Call Files: A Case Study for Northern Long-eared Bats

Importance of Manually Vetting Acoustic Bat Call Files: A Case Study for Northern Long-eared Bats

Cave Biodiversity of Cumberland Gap National Historical Park

Recognized as an important pathway between the east coast and the interior of the United States, much of the Cumberland Gap has been protected as part of the Cumberland Gap National Historical Park (CUGA). CUGA also contains extensive karst habitats, including Gap Cave, one of the longest caves in Virginia. With the aim of better understanding the cave biodiversity of CUGA, we conducted biological surveys in park caves and compiled records of other animals from CUGA caves, including bat monitoring data extending back more than 35 years. Results of that work include: (1) collecting five new cave-obligate species (troglobionts) from CUGA caves, increasing the number of troglobionts known from CUGA from 11 to 16; (2) increasing the total records of troglobionts in CUGA caves from 17 to 39; (3) finding an undescribed isopod (now described as Lirceus zigleri) in the Gap Cave stream; (4) noting six species of bats, including two federally endangered species—Indiana bats (Myotis sodalis) and northern long-eared bats (Myotis septentrionalis)—from CUGA caves; and (5) recognizing that Gap Cave once hosted one of the largest known populations of Indiana bats in Virginia. We present an annotated list of the animals found in the caves of the park. The caves of the Cumberland Gap National Historical Park provide critical habitat to two groups of species with distinct conservation concerns: poorly known troglobionts that exhibit extreme endemicity and bats under threat from white-nose syndrome disease.

Disentangling genetic diversity of Myotis septentrionalis: population structure, demographic history, and effective population size

Abstract Myotis septentrionalis (Northern Long-eared Bat) has recently suffered a >90% decline in population size in North America due to white-nose syndrome (WNS). We assessed genetic diversity, population structure, current effective population size, and demographic history of M. septentrionalis distributed across the United States to determine baseline levels pre-WNS. We analyzed RADseq data from 81 individuals from Kentucky, Louisiana, Michigan, Minnesota, North Carolina, Oklahoma, and Wisconsin. Additionally, we examined population genetic structure using discriminant analysis of principal components, fastStructure, and STRUCTURE. We then estimated effective population size and demographic history using fastsimcoal2. Similar levels of genetic diversity were found across all samples. We found no population genetic structure in the varied analyses from these contemporary samples. The best model for demographic history estimated a rapid population expansion followed by a slower expansion approximately 340,000 years ago. The vagility of M. septentrionalis, along with male dispersal and random mating, may provide a buffer against serious bottleneck effects stemming from rapid population declines due to WNS. This research provides a baseline for tracking and monitoring the influence of WNS on genetic diversity such as potential reduced diversity or increased population structuring in the future.

Using PIT tags to infer bat reproductive status and parturition date: busy nights during lactation

Abstract Passive integrated transponders (PIT tags) can aid in the collection of important demographic data for species for which other methods, such as GPS technology, are not suitable. PIT tags can be particularly suitable to monitor small and cryptic species like bats and permit inference on their behavioral ecology. Literature for several species of bats states that females change their nightly activity patterns—going out and in of the roost only once per night during gestation compared to several times during lactation. Hence, we tested whether PIT tag detection patterns could be used to infer reproductive status and parturition date of female bats. From 2017 to 2021, we recorded detections of PIT-tagged little brown (Myotis lucifugus) and northern long-eared bats (M. septentrionalis) at the entrance of 2 maternity roosts in Québec and Newfoundland, Canada. We also used the maternity roost in Québec as a case study to further evaluate the potential of this method to link behavior and demography and investigated factors affecting parturition date. We were able to infer reproductive status for 63% to 97% of tagged individuals detected during both the gestation and the lactation periods, and parturition date for 61% to 95% of reproductive individuals, depending on the year and roost. Early spring arrival at the roost and warm spring mean temperature at night were associated with earlier parturition dates. Herein, we highlight that PIT tag systems may be useful to detect changes in activity patterns of female bats and infer individual reproductive parameters, which is on the long-term less stressful for bats and easier for researchers. We demonstrate that this approach is useful to investigate intrinsic and extrinsic factors of reproductive parameters, improving our understanding of bat population dynamics resulting in more informed population management decisions.

Effects of bat white-nose syndrome on hibernation and swarming aggregations of bats in Ontario

Emerging infectious diseases can have substantial impacts on wildlife health, but also provide an opportunity to understand how populations respond to novel selective pressures. White-nose syndrome (WNS) has decimated some populations of bats in eastern North America, but impacts vary among species. We counted bats in 11 hibernacula in Ontario, Canada, before and after WNS arrived, and compared the relative abundance of 5 bat species captured pre-WNS (1966–1968 and 2007–2009) and post-WNS (2017–2019) during swarming at one of these hibernacula. Counts of hibernating bats declined by 87%–100% after WNS arrived. However, we observed a recent, gradual increase in bat counts in the two largest, monitored hibernacula. During swarming, little brown bat ( Myotis lucifugus (Le Conte, 1831)) was the most frequently captured bat in all sampling periods. Capture frequency of northern long-eared bat ( Myotis septentrionalis (Trouessart, 1897)) declined precipitously after WNS arrived, while eastern small-footed bat ( Myotis leibii (Audubon and Bachman, 1842) represented a higher proportion of bat captures in 2017–2019 compared to other sampling periods. Our data suggest potential adaptation of some bat populations to WNS, but also highlight the importance of protecting bats and their habitat during the active season to facilitate population recovery.

Network analysis of a northern long-eared bat (Myotis septentrionalis) maternity colony in a suburban forest patch

Abstract Many bat species are highly social, forming groups of conspecifics, particularly during the maternity season. In temperate North America, these social groups are typically comprised of closely related individuals or individuals that share some common trait (i.e. reproductive state or shared hibernacula from the previous winter). In the summer, when bats use forests for day-roosts, these social groups often demonstrate nonrandom patterns of periodically associating in common roosts and disassociating using different roosts as a ‘fission–fusion society’. As cave hibernating bat species in North America continue to decline due to the impacts of White-nose Syndrome, opportunities to describe these dynamics are becoming rare. Unfortunately, these patterns often are still poorly documented, yet understanding these behaviors is critical for species-specific habitat conservation and management. In our study, we tracked female northern long-eared bats (Myotis septentrionalis) to their day-roosts in a small, suburban forest fragment in coastal New York, USA, in the summers of 2018 and 2019. We confirmed that the bats shared roost sites and, using network analyses, analyzed social dynamics and space use. In contrast to previous research on this imperiled species in large, unfragmented core forests, we found a more dense, connected roost network that concentrated around forest patch edges. Unusual for this species, primary roosts were anthropogenic structures. Our findings suggest that northern long-eared bats can utilize small forest patches and that incorporation of specific types of anthropogenic roosts might be an effective strategy for long-term conservation in more urbanized landscapes where forest management actions to enhance day-roosting conditions are impractical and the risk of stochastic loss of roosts is high.

Seasonal differences in day-roost selection by Northern long-eared bats (Myotis septentrionalis) in Louisiana and a meta-analytical comparison across North America

Resting-site selection involves some of the most important decisions made by organisms. For forest-dwelling bats, where to roost influences not only resting but also many other activities that affect fitness such as raising young, thermoregulation, communication, and evasion of predators. Across much of North America, many bats roost in trees during summer and hibernate in caves during winter and as such, most of the focus on roosting ecology and forest management has been during summer. Along much of the Atlantic and Gulf coastal plains in the southern portion of North America, winters are relatively warm, few caves exist, and many bat species are active. Herein, we described the tree-roosting ecology of Northern long-eared bats (Myotis septentrionalis) in Louisiana in both summer and winter, examined roost selection, compared selection seasonally, and compared various aspects of roosting ecology in Louisiana to other areas across North America. We found that in Louisiana M. septentrionalis roosted primarily in pine trees and found no significant differences in roosting characteristics between sexes. Year-round, bats preferred roosts in trees in more advanced stages of decay than available trees. In summer, bats selected for plot level characteristics such as higher density of trees that were large and in more advanced stages of decay. In contrast, in winter, bats selected for tree characteristics such as those with taller, greater diameter and with more exfoliating bark. Comparisons with 21 other studies across North America indicated variation in selected roost characteristics among regions. These results highlight variability in roost selection through space and time and suggest that management strategies that are tailored to specific sites may be most effective for enhancing roosting opportunities of M. septentrionalis and ultimately the conservation of this species.

A Survey of Bats at Lilley Cornett Woods Appalachian Ecological Research Station, Letcher County, Kentucky, before the Arrival of White-nosed Syndrome

Bat species associated with the Lilley Cornett Woods Appalachian Ecological Research Station (LCW) were documented over two field seasons. Mist netting was conducted during July 2009 [13 net nights], whereas acoustical monitoring was conducted from May–August 2010, with sampling occurring continuously for 85 nights. A total of 26 individuals, representing 5 species were captured: little brown bat (Myotis lucifugus; n = 11), tricolored bat (Perimyotis subflavus; n = 6), northern long-eared bat (Myotis septentrionalis; n = 6), big brown bat (Eptesicus fuscus; n = 2), hoary bat (Lasiurus cinereus; n = 1). There were 34,425 identified echolocation passes identifying 9 different bat species, i.e., tricolored bat, little brown bat, northern long-eared bat, big brown bat, Indiana bat (Myotis sodalis), gray bat (Myotis grisescens), eastern red bat (Lasiurus borealis), eastern small-footed bat (Myotis leibii), and evening bat (Nycticeius humeralis)]. Multiple species detected at LCW have been classified by the U.S. Fish and Wildlife Service (USFWS) as endangered (Indiana bat and gray bat) and threatened (northern long-eared bat). Since it was first detected, WNS has spread rapidly across North America and is associated with host mortality of >90%. We strongly recommend the Chiropteran community at LCW be resurveyed to assess the impacts of WNS, and that a passive acoustical monitoring program be developed and integrated into the area's long-term management plan.

Roosting Behavior of Northern Long-Eared Bats (Myotis septentrionalis) in an Urban-Adjacent Forest Fragment

Throughout the Midwest United States, agricultural and urban development have fragmented natural areas, with a disproportionate effect on forests and wetlands. The resulting habitat loss, compounded with the spread of white-nose syndrome (WNS), has caused precipitous population declines in several forest-obligate bat species. In 2019, we discovered a remnant northern long-eared bat (Myotis septentrionalis Trouessart) maternity colony in a small forest fragment adjacent to a restored wetland in northeastern Indiana, USA. We investigated roost selection in this colony during the summers between 2019 and 2021 by attaching radio transmitters to northern long-eared bats and tracking them to day roosts. We measured tree, plot, and landscape-level characteristics for each roost and for a randomly selected available tree in the same landscape, then compared characteristics using paired t-tests. Over 70 net nights, we captured and tracked 4 individuals (1 juvenile male, 1 post-lactating female, and 2 lactating females) to 12 different roosts. There were, on average, 3.5 times more standing dead trees (snags) in plots around roosts compared to available trees (t = −4.17, p = 0.02). Bats in this maternity colony selected roosts near a stretch of flooded forest (which contained 83% of roosts) dominated by solar-exposed, flood-killed snags. These roosts likely provide warm microclimates that facilitate energy retention, fetal development, and milk production. By describing roosts within this landscape, we provide insight into the resources that enable an endangered bat species to persist in urbanized forest fragments.

The First Confirmed Occurrence of Myotis septentrionalis (Northern Long-eared Bat) on the Delmarva Peninsula

In 2016, Myotis septentrionalis (Northern Long-eared Bat) was listed as federally threatened in the United States, due largely to declines from white-nose syndrome (WNS). The dramatic decline of this species heightens the significance of new occurrences outside the known range. Herein we report the first ever capture and genetic confirmation of an adult male Northern Long-eared Bat on the Delmarva Peninsula, MD, located on the northern portion of the Atlantic Coastal Plain. This finding suggests further surveys are needed along the Atlantic Coastal Plain to determine if this region is being increasingly utilized by this species in the era of WNS.

Changes in the Forest Bat Community After Arrival of White-Nose Syndrome in the Ouachita Mountains of Arkansas

Populations of some cave-hibernating bats have undergone declines in recent years due to an introduced fungus (Pseudogymnoascus destructans) that causes the disease white-nose syndrome (WNS), which is often fatal to bats during hibernation. Unprecedented declines in cave-hibernating species have the potential to change community composition via numerous mechanisms, including competitive release. We trapped bats for 6 years in the Ouachita Mountains of Arkansas prior to the arrival of WNS in the region and compared capture rates of 7 species to capture rates collected in 2020–2021 after WNS establishment. We found a 98% decline in Myotis septentrionalis (Northern Long-eared Bat) and a 77% decline in Perimyotis subflavus (Tricolored Bat) after WNS became prevalent. Nycticeius humeralis (Evening Bat) captures increased by 220% after WNS. Capture rates of Eptesicus fuscus (Big Brown Bat) increased by 100%, but this increase was not significant. We also found no significant differences in captures rates for Lasiurus borealis (Eastern Red Bat), Lasiurus seminolus (Seminole Bat), and Lasiurus cinereus (Hoary Bat) after the arrival of WNS. Our results indicate that the forest bat community of the Ouachita Mountains has been altered since the arrival of WNS in 2012, but it is unknown if these changes are permanent or if species will decline further or recover via adaptive or genetic changes in their populations in the future.

Characteristics of Day-Roosts Used by Northern Long-Eared Bats (Myotis septentrionalis) in Coastal New York

In North America, Myotis septentrionalis (Northern Long-eared Bat) has experienced precipitous declines from white-nose syndrome. As these bats become rare and difficult to capture, additional day-roost assessments to inform management may fill gaps in our understanding, particularly in habitats and regions where such roosts have never been surveyed. Over 2 summers, we radio-tracked 16 individuals from a maternity colony on Long Island, NY, in a small forested patch surrounded by development and ocean. These bats disproportionately selected small, suppressed Robinia pseudoacacia (Black Locust) trees or snags for roosting. Generally, roosts occurred within the interior or edges of this forest patch, rather than surrounding suburbia, reinforcing the hypothesis that Northern Long-eared Bats are forest adapted. Our study shows even small tracts of forest in coastal, urban areas may have conservation value in providing day-roost and foraging habitat.

Unique Land Cover Classification to Assess Day-Roost Habitat Selection of Northern Long-Eared Bats on the Coastal Plain of North Carolina, USA

Reproductively successful and over-wintering populations of the endangered northern long-eared bat (Myotis septentrionalis) have recently been discovered on the Coastal Plain of North Carolina. Empirical data on resource selection within the region is limited, likely hindering management of these coastal forests. Our objectives were to determine roosting home range size, selection of day-roost tree species, second- and third-order roosting habitat selection, and to quantify the overall availability of resources in the surrounding landscape. We found core and peripheral roosting home range estimates were large, yet similar to observations from other areas of contiguous forests. Prior to juvenile volancy, female northern long-eared bats appear to select red maple (Acer rubrum), water ash (Fraxinus caroliniana), and loblolly pine (Pinus taeda) as day-roosts, but then use sweetgum (Liquidambar styraciflua), swamp bay (Persea palustris), and water tupelo (Nyssa aquatica) after juvenile volancy. At the second-order spatial scale, roosting home ranges were associated with woody wetlands farther from anthropogenic development and open water. However, within the third-order scale, northern long-eared bats were associated with undeveloped woody wetlands and upland forests, areas containing shorter trees and occurring proximal to open water. Peripheral and core areas were predicted to comprise approximately 20% of the local landscape. Our results show that complex and large tracts of woody wetlands juxtaposed with upland forests in this part of the Coastal Plain may be important for northern long-eared bats locally, results largely consistent with species management efforts in eastern North America.

Summer Populations of Northern Long-eared Bat in an Eastern Kentucky Forest Following Arrival of White-nose Syndrome

Myotis bats have experienced significant population losses due to white-nose syndrome (WNS) throughout large portions of their distributions in eastern North America. As closed-space foragers, these species comprise an important feeding guild within eastern forests. An understanding of where summer populations remain and how their ecology has changed following impact from WNS is needed to assess fully the recovery potential of Myotis bats. We used acoustic sampling, capture surveys, radiotelemetry and roost surveys from 2015 to 2018 to evaluate the status of northern long-eared bat (Myotis septentrionalis) in an eastern Kentucky forest following region-wide impacts from WNS to this species. Acoustic activity of Myotis remained unchanged over the 4 y of sampling, with activity of these bats greatest in mid- to late July. Northern long-eared bats represented 97% of the Myotis captured, indicating activity levels likely reflected patterns for this species. We located 18 roost trees of northern long-eared bats in five tree species, including both live and dead trees. All roost trees were on upper slopes within 100 m of ridge top roads. Maximum exit counts, 24 and 21, at two roosts occurred in late May and early June, suggesting these dates represented the summer maternity period of northern long-eared bats in this forest. Our results demonstrated that post-WNS populations of northern long-eared bats on Robinson Forest formed small colonies, day-roosted in trees near roads on forested ridge tops, were reproductively active, and maintained steady levels of activity across the 4 y of sampling. These data suggest that local populations of northern long-eared bats are surviving WNS and continue to persist during summer months in forests of the Appalachian Mountain region. We hypothesize presence of ridge top roads, often associated with forest logging operations, may be important habitat elements for increasing availability of preferred roosting habitat for summer populations of northern long-eared bats in actively managed forests.

Endangered Myotis bats forage in regeneration openings in a managed forest

Bat populations face numerous threats, including the loss of forests in which they roost and forage. Present-day forests are commonly managed for timber harvesting, recreation, and wildlife. Understanding bat responses to forest management is crucial for balancing the conservation of endangered bats and forest restoration. We used radio telemetry to study nocturnal movements and habitat selection patterns of female and juvenile bats of two forest-dependent, federally listed bat species in an oak-dominated managed forest. We estimated foraging space use and assessed habitat selection for 33 northern long-eared bats (Myotis septentrionalis) and 25 Indiana bats (Myotis sodalis) from May to August 2014–2017 in south-central Indiana, USA. Myotis septentrionalis space use averaged 176 ha and bats selected water, historic thinning, and patch cuts (≤4 ha) over other habitats, with all but one bat avoiding larger openings (≥4-ha clearcuts). Myotis sodalis space use averaged 343 ha and bats selected 4-ha patch cuts, historic openings, and historic thinning over other habitats. In contrast to M. septentrionalis, one-third of the M. sodalis foraged over larger clearcuts, while two-thirds foraged over smaller openings and thinnings. We showed that bats were attracted to small regeneration harvests of varying structural ages. Forests maintained for a mix of mature stands, thinned stands, shelterwoods, small regenerative cuts (<7 ha), and small water sources should provide suitable foraging habitat for these endangered Myotis species, while also promoting forest regeneration.

Northern Long-Eared Bat (Myotis septentrionalis) Day-Roost Loss in the Central Appalachian Mountains following Prescribed Burning

Before the arrival of white-nose syndrome in North America, the northern long-eared bat (Myotis septentrionalis) was a common cavity-roosting bat species in central Appalachian hardwood forests. Two successive prescribed burns on the Fernow Experimental Forest, West Virginia, in 2008 and 2009, were shown to positively affect maternity colony day-roost availability and condition in the near-term. However, whether immediate benefits were temporary and if burned forests actually experienced an accelerated loss of trees and snags possibly suitable for bats more than background loss in unburned forests became an important question following the species’ threatened designation. In 2016, we revisited 81 of 113 northern long-eared bat maternity colony day-roosts initially discovered in 2007–2009 with the objective of ascertaining if these trees and snags were still standing and thus potentially “available” for bat use. Initial tree or snag stage condition class and original year of discovery were contributory factors determining availability by 2016, whereas exposure to prescribed fire and tree/snag species decay resistance were not. Because forest managers may consider using habitat enhancement to improve northern long-eared bat survival, reproduction, and juvenile recruitment and must also protect documented day-roosts during forestry operations, we conclude that initial positive benefits from prescribed burning did not come at the expense of subsequent day-roost loss greater than background rates in these forests at least for the duration we examined.

Integrating Multiple Survey Techniques to Document a Shifting Bat Community in the Wake of White-Nose Syndrome

AbstractThe long-term study of bat communities often depends on a diverse set of sampling methodologies that are chosen based on the species or habitat management priorities of the research project. Integrating the data from a diverse set of methodologies (such as acoustic monitoring and mist net sampling) would improve our ability to characterize changes in community structure or composition over time, such as one would expect following an emergent infectious disease such as white-nose syndrome. We developed a Bayesian state-space model to integrate these disparate data into a common currency (relative abundance). We collected both acoustic monitoring and mist net capture data over an 8-y period (2006–2014) to document shifts in the bat community in central New England, USA, in response to the onset of white-nose syndrome in 2009. The integrated data model shows a significant decline in the abundance of little brown bat Myotis lucifugus, northern long-eared bat Myotis septentrionalis, and hoary bat Lasiurus cinereus, and an increase in abundance of the eastern small-footed bat Myotis leibii and the eastern red bat Lasiurus borealis. There was no evidence for a change in abundance in the big brown bat Eptesicus fuscus since the onset of white-nose syndrome. The consistency of this model with regional estimates of decline over the same time period support the validity of our relative abundance estimate. This model provides the opportunity to quantify shifts in other communities where multiple sampling methodologies were employed, and therefore provides natural resource managers with a robust tool to integrate existing sampling data to quantify changes in community composition that can inform conservation and management recommendations.

Diurnal roost selection of northern long-eared bats on the southern edge of their range

Mortality from white-nose syndrome has made management and recovery of the northern long-eared bat (Myotis septentrionalis) a priority. Ensuring availability of diurnal summer roosts, where gestation and rearing of young occurs, is a critical component of successful recovery. However, observed variation in roost selection across the species’ range makes extrapolating data across physiographic regions and habitat types difficult, and limited information exists on roost selection at the southern range extent of the species. Therefore, we examined M. septentrionalis diurnal roost selection toward the southern range extent in northern Georgia, USA. We identified characteristics of desirable roosts for all individuals and for reproductive females by comparing roosts to surrounding vegetation and topographic characteristics at the plot, home range (67 ha), and landscape (17.2 km2) scales. From May to July 2014–2017, we radio tagged 12 female and 4 male M. septentrionalis and located 37 roosts. Bats roosted in cavities, loose bark, and hollow boles of 16 tree species. Over half of roosts (53%) were located below the canopy and in trees with larger diameters than surrounding trees. Bats disproportionately roosted in snags, with relative probability of selecting a snag roost increasing with snag density at the plot scale. On low gradient slopes, roosts occurred more frequently on west-facing aspects but as slope increased bats showed no aspect preference. Results indicate individuals in our study area are indifferent to or actively avoid roosts with high solar exposure. Our results support previous research that management efforts should focus on creating and retaining snags across the landscape and highlight the need for management to consider regional variation in habitat use.

White-nose syndrome-related changes to Mid-Atlantic bat communities across an urban-to-rural gradient

BackgroundWhite-nose Syndrome (WNS) has reduced the abundance of many bat species within the United States’ Mid-Atlantic region. To determine changes within the National Park Service National Capital Region (NCR) bat communities, we surveyed the area with mist netting and active acoustic sampling (2016–2018) and compared findings to pre-WNS (2003–2004) data.ResultsThe results indicated the continued presence of the threatened Myotis septentrionalis (Northern Long-eared bat) and species of conservation concern, including Perimyotis subflavus (Tri-colored bat), Myotis leibii (Eastern Small-footed bat) and Myotis lucifugus (Little Brown bat). However, we documented a significant reduction in the abundance and distribution of M. lucifugus and P. subflavus, a decrease in the distribution of M. septentrionalis, and an increase in the abundance of Eptesicus fuscus (Big Brown bat).ConclusionsDocumented post-WNS M. septentrionalis recruitment suggests that portions of the NCR may be important bat conservation areas. Decreases in distribution and abundance of P. subflavus and M. lucifugus indicate probable extirpation from many previously occupied portions of the region.