Lasiurus Borealis Research Articles

Molecular detection of the causative agent of white-nose syndrome on Rafinesque's big-eared bats (Corynorhinus rafinesquii) and two species of migratory bats in the southeastern USA.

Pseudogymnoascus destructans, the causal agent of white-nose syndrome (WNS), is responsible for widespread mortality of hibernating bats across eastern North America. To document P. destructans exposure and infections on bats active during winter in the southeastern US, we collected epidermal swabs from bats captured during winters 2012-13 and 2013-14 in mist nets set outside of hibernacula in Tennessee. Epidermal swab samples were collected from eight Rafinesque's big-eared bats (Corynorhinus rafinesquii), six eastern red bats (Lasiurus borealis), and three silver-hair bats (Lasionycteris noctivagans). Using real-time PCR methods, we identified DNA sequences of P. destructans from skin swabs of two Rafinesque's big-eared bats, two eastern red bats, and one silver-haired bat. This is the first detection of the WNS fungus on Rafinesque's big-eared bats and eastern red bats and the second record of the presence of the fungus on silver-haired bats.

Temperatures below leaf litter during winter prescribed burns: implications for litter-roosting bats

Some bat species, including eastern red bats (Lasiurus borealis), roost for short periods beneath leaf litter on the forest floor during winter in the south-eastern USA, a region subjected to frequent fire. The variability in fuel consumption, the heterogeneous nature of burns, and the effects of litter and duff moisture on forest-floor temperatures during winter burning could influence potential survival for bats beneath the leaf litter if they are unable to escape on-coming flames. We measured temperatures below leaf litter in 64 south-slope plots during nine controlled burns in the Ouachita Mountains of Arkansas to determine the probability of survival. Maximum temperature recorded under leaf litter at each plot averaged 292°C (±20 s.e.) and ranged from 10 to 717°C. Only three (5%) of the plots experienced temperatures that were deemed survivable (<60°C sustained for 60 s) during burns on warmer winter days (air temperatures 15.0–26.1°C). Temperatures below the leaf litter measured just before the arrival of fire (average = 19.6°C) suggested that if bats were roosting in plots they would have been in shallow torpor, which would have enabled faster escape from approaching flames. Burning during the warmer periods of winter (e.g. ≥15°C) and during afternoons could potentially improve survival by bats roosting under leaf litter by reducing arousal and escape times.

Relationships between bat occupancy and habitat and landscape structure along a savanna, woodland, forest gradient in the Missouri Ozarks

ABSTRACTMany land‐management agencies are restoring savannas and woodlands using prescribed fire and forest thinning, and information is needed on how wildlife species respond to these management activities. Our objectives were to evaluate support for relationships of bat site occupancy with vegetation structure and management and landscape composition and structure across a gradient of savanna to forest in the Missouri Ozark Highlands, USA. We selected study sites that were actively managed for savanna and woodland conditions and control areas on similar landforms that had succeeded to closed‐canopy forest. We used Anabat detectors to survey bats during the summers of 2010, 2011, and 2012. We fit single‐species site‐occupancy models to estimate detection probability and site occupancy. We evaluated a priori hypotheses in an information theoretic approach by evaluating support for candidate models that included habitat, landscape, and management effects. Site occupancy of evening bats (Nycticeius humeralis) was negatively related to poletimber and sawtimber density and positively related to fire frequency, while northern long‐eared bat (Myotis septentrionalis) site occupancy was positively related to poletimber density and negatively related to understory stem densities. Site occupancy of big brown bats (Eptesicus fuscus), eastern red bats (Lasiurus borealis), and tri‐colored bats (Perimyotis subflavus) were mostly not related to local vegetation structure and site occupancy was high across the savanna, woodland, forest gradient. We found more consistent and larger effect sizes for landscape‐scale than for habitat‐scale relationships; therefore, land managers should be cognizant of large‐scale patterns in land cover when making local management decisions for these species. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Bat rabies in Oklahoma

Based on identification of bat species submitted to the Oklahoma State Department of Health for rabies testing, and from literature accounts, the incidence of rabies in bats in Oklahoma from 1987–2012 is discussed. Of the 1,079 bats submitted, 1,061 were tested for rabies over the last 26 y. Twelve species were identified. The most-frequently submitted species was the Eastern red bat, Lasiurus borealis. The percentage of bats that tested positive for rabies was 9.7%.

Site occupancy of foraging bats on landscapes of managed pine forest

The ability to fully evaluate potential relationships between forest management and bats is limited without information from relevant spatial scales. Further, knowledge of bat ecology in intensively managed forests is fairly limited even though these forests are a substantial portion of the forested landscape in the southeastern U.S. Therefore, we used occupancy models to examine influence of small-scale vegetation characteristics and large-scale spatial features on foraging patterns of bats within 6 managed-pine (Pinus spp.) forest landscapes in the southeastern U.S. Coastal Plain. We conducted repeated acoustic surveys to determine species presence/non-detection and evaluated a priori models relating detection probability and occupancy to site- and landscape-level metrics for 6 species/genera. Detection of big brown (Eptesicus fuscus) and eastern red (Lasiurus borealis)/Seminole (L. seminolus) bats (eastern red and Seminole bats combined) decreased with increasing basal area, and detection of big brown and Brazilian free-tailed bats (Tadarida brasiliensis) increased over the summer sampling period. Relationships between occupancy and habitat metrics were species-specific but consistent with previous studies. Occupancy for most bat species was lower at sampling sites with higher vegetation clutter and higher basal area. In contrast to most previous studies, occupancy of all bat species investigated was unrelated to or negatively influenced by distance to water. Although site- and landscape-level features influenced occupancy, our results indicate that site-specific features (vegetation clutter and basal area) influenced most species. Therefore, stand-level management activities that decrease vegetation structure, such as thinning intermediate-aged stands and/or controlling midstory vegetation (e.g., fire or herbicide applications), likely will maintain or increase suitability of managed pine forest stands and landscapes for many bat species in the southeastern Coastal Plain. The forest mosaics that we sampled, consisting primarily of managed pine stands intermingled with non-production habitat types, supported a large proportion of the bat community associated with forests of the Coastal Plain which suggests the compatibility of timber production and bat conservation objectives.

Stable hydrogen isotopes record the summering grounds of eastern red bats (Lasiurus borealis).

Bats face numerous threats associated with global environmental change, including the rapid expansion of wind-energy facilities, emerging infectious disease, and habitat loss. An understanding of the movement and migration patterns of these highly dispersive animals would help reveal how spatially localized the impacts from these threats are likely to be on bat populations, thus aiding in their conservation. Stable hydrogen isotope ratios (δ2H) can be used to infer regions where bats have foraged during the summer molt season, thus allowing an assessment of summering location and distance of movement of bats sampled during other times of year. However, a major impediment to the application of δ2H for inference of bat movements is that the relationship between δ2H of bat hair and precipitation tends to be species specific and is still unknown for some key species of conservation concern. We addressed this issue by using geo-referenced museum specimens to calibrate the relationship between δ2H of hair (δ2Hhair) and long-term δ2H of growing-season precipitation (δ2HGSprecip) at the site of collection for eastern red bats (Lasiurus borealis), one of the main species of bats experiencing large numbers of fatalities at wind-energy facilities in North America. Based on comparison of δ2Hhair and δ2HGSprecip values for males we estimated a period of molt of June 14–August 7. Within this period, male and female red bats exhibited a significant positive relationship between δ2Hhair and δ2HGSprecip. These results establish the relationship between δ2Hhair and δ2HGSprecip for red bats, which is necessary for the use of δ2Hhair to infer the movement and migration patterns of this important species. These results provide a critical resource to conservation biologists working to assess the impacts of environmental change on bat populations.

Fatty acid methyl ester profiles of bat wing surface lipids.

Sebocytes are specialized epithelial cells that rupture to secrete sebaceous lipids (sebum) across the mammalian integument. Sebum protects the integument from UV radiation, and maintains host microbial communities among other functions. Native glandular sebum is composed primarily of triacylglycerides (TAG) and wax esters (WE). Upon secretion (mature sebum), these lipids combine with minor cellular membrane components comprising total surface lipids. TAG and WE are further cleaved to smaller molecules through oxidation or host enzymatic digestion, resulting in a complex mixture of glycerolipids (e.g., TAG), sterols, unesterified fatty acids (FFA), WE, cholesteryl esters, and squalene comprising surface lipid. We are interested if fatty acid methyl ester (FAME) profiling of bat surface lipid could predict species specificity to the cutaneous fungal disease, white nose syndrome (WNS). We collected sebaceous secretions from 13 bat spp. using Sebutape(®) and converted them to FAME with an acid catalyzed transesterification. We found that Sebutape(®) adhesive patches removed~6× more total lipid than Sebutape(®) indicator strips. Juvenile eastern red bats (Lasiurus borealis) had significantly higher 18:1 than adults, but 14:0, 16:1, and 20:0 were higher in adults. FAME profiles among several bat species were similar. We concluded that bat surface lipid FAME profiling does not provide a robust model predicting species susceptibility to WNS. However, these results provide baseline data that can be used for lipid roles in future ecological studies, such as life history, diet, or migration.

Activity and diet of bats in conventional versus organic apple orchards in southern Michigan

Organic farming practices have been suggested as a conservation strategy that can provide productive foraging sites for insectivorous bats in agricultural areas. We tested the hypothesis that the number and diversity of insects captured and the resulting activity and diet of bats would differ between organic and conventional apple orchards. During the summer of 2009 and 2010, we captured 131 Big Brown Bats (Eptesicus fuscus) and five Eastern Red Bats (Lasiurus borealis) by mist netting in four organic and four conventional orchards in Michigan. Acoustic monitoring revealed that most calls (59%) were produced by Big Brown Bats, followed by Hoary Bats (L. cinereus), Eastern Red Bats, and unidentified species of Myotis. Most insects (96%) captured in light traps were Coleoptera, Diptera, Hemiptera, Lepidoptera, and Trichoptera; fecal analysis indicated that Coleoptera dominated the diet of Big Brown Bats (79% by volume), followed by Diptera (14%). There were no significant differences between organic and conventional orchards in number of insects captured with light traps, bats captured with mist nets, acoustic recordings of bats, or proportion of Coleoptera and Diptera consumed by the bats. However, the taxonomic composition of captured insects and acoustic recordings was not homogenous among orchards in either group, suggesting that factors other than farming practices were more important in determining which insects and bats were found in the small orchards typical of southern Michigan.

Structure and Reproductive Patterns in the Summertime Forest-Bat Community of Southeastern Texas

Abstract Forests of eastern Texas represent the westernmost extent of the southern pine forests and part of the pine belt of the forested Gulf coastal plain. Bat community assemblages in similar forests throughout southeastern United States have been documented in various studies, but only scant data are available for Texas. The purpose of this study was to characterize the assemblage and investigate reproductive patterns of the summer bat community in the austroriparian forest of eastern Texas. Using mist nets, we captured bats during summers 2009–2011 and recorded species, gender, age and reproductive condition. We captured 382 bats of eight species: Seminole Lasiurus seminolus (n = 163), evening Nycticeius humeralis (n = 86), big brown Eptesicus fuscus (n = 57), eastern red Lasiurus borealis (n = 31), southeastern myotis Myotis austroriparius (n = 21), tri-colored Perimyotis subflavus (n = 19), Mexican free-tailed Tadarida brasiliensis (n = 4), and hoary Lasiurus cinereus (n = 1) bats. Analysis of reproductive data suggests that three of these species (big brown, evening, and Seminole bats) may be following a reproductive strategy—extended seasonal monoestry (births of single litters spanning a particular season)—different than their previously reported pattern of synchronous monoestry.

Offshore Activity of Bats Along the Mid-Atlantic Coast

Abstract Bat mortality caused by terrestrial wind-power plants has been documented and offshore wind-power developments may have similar effects. Determining which bat species occur offshore, how far they range from shore, and predictors of high activity may be helpful to developers and wildlife managers. We studied bat activity off the mid-Atlantic coast, using ultrasonic detectors mounted on ships in spring and fall 2009 and 2010. We investigated the association between nightly bat activity and weather variables, including wind speed, air temperature, and barometric pressure. Echolocation passes of bats totaled 166; maximum detection distance from shore was 21.9 km, and mean distance was 8.4 km. Most passes were identified as Lasiurnis borealis (Eastern Red Bats), representing 78% of bats identified to species or species group. Bat activity decreased as wind speed increased, but activity did not differ with distance from shore. Offshore wind projects proposed for locations beyond the maximum detection d...

A Comparison of Passive and Active Acoustic Sampling for a Bat Community Impacted by White-Nose Syndrome

Abstract In the summers of 2011 and 2012, we compared passive and active acoustic sampling for bats at 31 sites at Fort Drum Military Installation, New York. We defined active sampling as acoustic sampling that occurred in 30-min intervals between the hours of sunset and 0200 with a user present to manipulate the directionality of the microphone. We defined passive sampling as acoustic sampling that occurred over a 12-h period (1900–0700 hours) without a user present and with the microphone set in a predetermined direction. We detected seven of the nine possible species at Fort Drum, including the federally endangered Indiana bat Myotis sodalis, the proposed-for-listing northern bat M. septentrionalis, the little brown bat M. lucifugus, and the big brown bat Eptesicus fuscus, which are impacted by white-nose syndrome (WNS); and the eastern red bat Lasiurus borealis, the hoary bat L. cinereus, and the silver-haired bat Lasionycteris noctivagans, which are not known to be impacted by WNS. We did not detect two additional WNS-impacted species known to historically occur in the area: the eastern small-footed bat Myotis leibii and the tri-colored bat Perimyotis subflavus. Single-season occupancy models revealed lower detection probabilities of all detected species using active sampling versus passive sampling. Additionally, overall detection probabilities declined in detected WNS-impacted species between years. A paired t-test of simultaneous sampling on 21 occasions revealed that overall recorded foraging activity per hour was greater using active than passive sampling for big brown bats and greater using passive than active sampling for little brown bats. There was no significant difference in recorded activity between methods for other WNS-impacted species, presumably because these species have been so reduced in number that their “apparency” on the landscape is lower. Finally, a cost analysis of standard passive and active sampling protocols revealed that passive sampling is substantially more cost-effective than active sampling per hour of data collection. We recommend passive sampling over active sampling methodologies as they are defined in our study for detection probability and/or occupancy studies focused on declining bat species in areas that have experienced severe WNS-associated impacts.

Resource utilization by foraging eastern red bats (Lasiurus borealis) in the Ozark Region of Missouri

Resource selection by animals influences ecological processes such as dispersal, reproduction, foraging, and migration. Little information exists regarding foraging resource selection by bats during the maternity season. We evaluated support for effects of landcover type, landform, and landscape pattern on resource selection by individual foraging female eastern red bats (Lasiurus borealis) during the maternity period and compared resource utilization for all individuals pooled (population level), individuals grouped by geographic location, and individuals grouped by stage of lactation (early, mid, and late). We used a resource utilization function (RUF) to relate landcover and landscape attributes to the utilization distributions of individual bats estimated by the fixed-kernel method. We radio-tracked 64 lactating red bats and estimated utilization distributions for 52 individuals. Mean home range size ranged from 1,041 to 1,588 ha from late to mid lactation. The global RUF model was significantly better than the null RUF model for 36 (70%) individuals and the magnitude and direction of coefficients varied among individuals. Resource utilization at the population level was, on average, positively related to ridges and upland drainage landforms, water landcover, and road density; and negatively related to urban and nonforest landcover and distance to edge. Resource use differed between geographic areas by canopy cover, water landcover, and road density. Canopy closure was positively related to RUF in both areas but was greater in the south area. Percent water negatively related to RUF in the north area and positively related in the south area. Road density had a positive relationship in the north and negative relationship in the south with RUF. We did not find a difference in mean RUF coefficients among lactation groups except for canopy cover. On average, canopy cover had a positive effect on use by bats during early and mid-lactation but a negative effect during late lactation. We suggest that management for red bats consider landscape components and provide a range of composition and structural diversity to enhance foraging use by red bats. In highly forested landscapes, gaps or openings may provide forest edges that are important for foraging and commuting. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

English

Protected areas may function as islands of habitat in otherwise adverse environments for many species of North American animals. It is currently unclear how to maintain suitable foraging habitat for bats within these areas. Bats are nocturnal and highly mobile, making their specific needs difficult to determine. Using data collected from acoustically surveyed sites within protected areas in the Oak Openings Region of Northwest Ohio, a biodiversity hotspot, we developed spatially explicit macrohabitat models using maximum entropy modeling (Maxent). We then used data collected by citizen scientists to test these models to determine their success in predicting species presence. We found that the models were successful (AUC values > 0.75) at predicting the occurrence of the seven species for which models were developed, Lasionycteris noctivagans, Lasiurus borealis, Lasiuruscinereus, Myotis lucifugus, Myotiss eptentrionalis, Nycticeius humeralis, and Perimyotis subflavus.  Within protected areas, it is important to manage for heterogeneous habitat composition at this intermediate scale to maintain potential for foraging areas for all occurring bat species. Data collected by citizen scientists is useful to test spatially explicit models and can potentially be used to monitor long term changes in bat species composition in these systems and across regions. Key words: Bats, maxent, northwest Ohio, citizen science, parklands.

Glycerophospholipid analysis of Eastern red bat (Lasiurus borealis) hair by electrospray ionization tandem mass spectrometry.

Pilosebaceous units found in the mammalian integument are composed of a hair follicle, the proximal portion of the hair shaft, a sebaceous gland, and the erector pili muscle. Pilosebaceous units release protective oils, or sebum, by holocrine secretion onto skin and hair through rupturing of sebocytes. Sebum is composed largely of polar and neutral lipids including glycerolipids, free fatty acids, sterols, wax esters, sterol esters, and squalene. In addition to these lipid classes, there is a small proportion of ionic/anionic glycerophospholipids (GPs). Composition of GPs on hair is rarely addressed despite their broad biological activities as signaling molecules and membrane stability. Furthermore, knowledge on GP composition in bats is lacking. Bat GP composition is important to document due to GP roles ranging from decreasing drag during migration to interaction with the integumentary microbiome. In this study, we analyzed GP molecular composition with liquid chromatography electrospray ionization tandem mass spectrometry and compared GP content to previous literature. A total of 152 GPs were detected. Broad GP classes identified include lysophosphatidylcholine, phosphatidylcholine (PC), lysophosphatidylethanolamine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidic acid, and phosphatidylglycerol, with PC being the most abundant class. The acyl components were consistent with fatty acid methyl esters and triacylglyceride moieties found in Eastern red bat sebum. Glycerophospholipid proportions of the hair surface were different from a previous study on bat lung surfactants. This study determined the broad class and molecular species of bat sebum GPs that may be used in future ecological studies in vespertilionid bats.

Red aviation lights on wind turbines do not increase bat-turbine collisions

Many hypotheses have been proposed to explain why bat–wind turbine collisions occur; however, most of these hypotheses have yet to be tested and with high numbers of bat fatalities reported annually at wind resource facilities globally, there is a real need to understand this phenomenon. In this study, we tested whether aviation lighting influenced the number of bat fatalities at wind turbines. Thus, at a utility-scale wind facility in north-central Texas, we explored whether bat fatalities were higher at wind turbines with red flashing aviation lighting compared with turbines without such lighting. Over a 5-year period, we recorded fatalities at wind turbines as part of a long-term fatality monitoring programme. During standardized searches, we collected 916 bat carcasses representing all six species known to be present at the site. We found that bat fatalities were higher at wind turbines without aviation lighting compared with those with; a pattern that was driven by one species, Lasiurus borealis, and there was no significant difference between fatalities at wind turbines with or without aviation lighting for any other species. Our study demonstrates that wind turbines should continue to be fitted with synchronized, flashing red aviation lights, as this form of lighting does not appear to be one of the potential causes of bat fatalities at wind resource facilities. We therefore support further research that explores possible alternative causes of bat–wind turbine interactions. More specifically, we reiterate that there is still a pressing need to determine the aspects of bat ecology that result in individuals coming into contact with wind turbines.

Development and characterization of microsatellite loci for eastern red and hoary bats (Lasiurus borealis and L. cinereus)

We developed ten dinucleotide and four tetranucleotide microsatellite markers for two species of tree bats from the family Vespertilionidae that are experiencing high mortality at wind energy facilities. Eleven of these loci were polymorphic in eastern red bats (Lasiurus borealis), whereas nine loci were polymorphic in hoary bats (Lasiurus cinereus). The number of alleles per locus ranged from 2 to 29 (mean = 14 alleles) and observed heterozygosity was generally high (mean 0.754, range 0.125–0.979). This set of microsatellite markers will be useful for studying population structure of these bats as part of a larger effort to understand the potential impacts of wind energy development on their populations.

Eastern Red Bat (Lasiurus borealis) Occurrence in Northern Alberta

Little is known about the distribution of Eastern Red Bats (Lasiurus borealis) at the northwestern edge of their range. We compiled and examined a data set of Eastern Red Bat capture and acoustic records from northern Alberta to examine their distribution, seasonality, and reproductive status near the edge of their range. Acoustic data suggested widespread but patchy distribution across Alberta. The number of captures of Eastern Red Bats in northern Alberta were similar to those of Hoary Bat (Lasiurus cinereus), suggesting that the species may be more common than previously thought. However, we failed to find evidence of reproduction in female Eastern Red Bats in Alberta. Small sample sizes, timing of surveys or difficulty in recognizing juveniles may explain the apparent lack of reproduction. Similar to Hoary Bats, reproductive adult male Eastern Red Bats have been captured with enlarged testes in northern Alberta in August, suggesting sperm production and possibly the start of breeding is taking place there in late summer. In northern Alberta, acoustic monitoring in early spring provided evidence of migratory bats early in the season. A better understanding of seasonal movement patterns and migration, habitat use, and reproduction of Eastern Red Bats in western Canada will require further study. Regardless, our data provide further evidence that the Eastern Red Bat is a more regular member of the bat fauna of northwestern Canada than previously recognized, which may be a result of an expanding distribution.

Pre-Construction Bat Activity At Four Wind Energy Sites in Northeastern British Columbia

We monitored pre-construction bat acoustic activity from 2007 to 2010 at 4 wind energy sites in northeastern British Columbia to determine nightly and seasonal activity patterns, relative detection rates of different species groups, and the implications for potential fatalities at northern wind facilities. Mean activity rates (August to September) ranged from 2.4 to 79.4 passes per detector-night at the 4 study areas. Activity differed between years for 3 study areas with multi-year data. Nightly variation in activity was pronounced, with wind speed and temperature recorded at meteorological towers explaining 47 to 61% of the variation in nightly activity. Detections were predominantly (60 to 96%) of Myotis bats. Only 1 to 18% of passes recorded at study areas were low-frequency bats (Big Brown Bat, Eptesicus fuscus; Silver-haired Bat, Lasionycteris noctivagans; Hoary Bat, Lasiurus cinereus), with L. cinereus accounting for <1% of the low-frequency passes. No Eastern Red Bats (Lasiurus borealis) were detected. Seasonal activity of low-frequency bats showed no evidence of an influx of spring migrants, but single-night activity spikes in late August and early September were suggestive of autumn migration. Activity of Myotis bats was highest in August and early September, a pattern consistent with resident populations. Results suggest that Myotis species may form a larger proportion of fatalities at northern wind energy facilities than at sites in more temperate regions.

Diversity and Distribution of Bats in the Northwest Territories

The occurrence of bats at the northern limit of their ranges in the Northwest Territories (NT), Canada, is not well documented. We provide information on the diversity and distribution of bat species in the NT by synthesizing available records. Before 2006, only 3 species of bats were known to occur in the NT: Little Brown Myotis (Myotis lucifugus), Northern Myotis (M. septentrionalis), and Hoary Bat (Lasiurus cinereus). Focused bat surveys as well as observations of bats reported by residents have added Long-eared Myotis (M. evotis), Long-legged Myotis (M. volans), Big Brown Bat (Eptesicus fuscus), and Silver-haired Bat (Lasionycteris noctivagans), for a total of 7 confirmed species, plus an additional species that is unconfirmed but suspected to occur (Eastern Red Bat, Lasiurus borealis). Range extensions for Little Brown Myotis, Hoary Bat, and Silver-haired Bat are reported. Both Little Brown Myotis and Northern Myotis are reproducing in the NT and are likely abundant in southern NT. Little Brown Myotis has been confirmed to overwinter in the NT and the northern limit of bat hibernation may be further north than previously supposed. Bats are widespread in the southern Central Plains region and gaps in occurrences likely reflect gaps in search effort. Nahanni National Park Reserve has high bat diversity and other parts of southwestern NT are suspected to have similarly high diversity, but have not yet been surveyed. There is evidence that the Eastern Shield region supports bats at relatively low densities. The northern distribution limit of bats in the NT is not known but is expected to occur in the Mackenzie Valley north of 62°N.

Bats of Nahanni National Park Reserve and Surrounding Areas, Northwest Territories

Abstract Few bat inventories have taken place in Northwest Territories (NWT), Canada, an area currently known to be the northernmost extent of the ranges of at least 6 bat species. Only 2 species of bats, the Northern Myotis (Myotis septentrionalis) and Little Brown Myotis (M. lucifugus), were previously known from the Nahanni National Park Reserve in the southwestern NWT. We used mistnets (15 nights) and AnaBat ultrasound detectors (23 nights) to survey bats in the South Nahanni River Watershed and surrounding area, to undertake the first formal survey of bats in the Northwest Territories. We confirmed the presence of the 2 species formerly documented from the area, as well as an additional 5 species not previously recorded from the region, including: Long-eared Myotis (Myotis evotis), Long-legged Myotis (M. volans), Big Brown Bat (Eptesicus fuscus), Hoary Bat (Lasiurus cinerus), and Eastern Red Bat (L. borealis). Four species were captured in mistnets (Northern Myotis, Little Brown Myotis, Long-eared My...