Northeastern Naturalist Vol. 22, No. 1 P.R. Moosman, Jr., D.P. Warner, R.H. Hendren, and M.J. Hosler 2015 NENHC-1 2015 NORTHEASTERN NATURALIST 22(1):NENHC-1–NENHC-13 Potential for Monitoring Eastern Small-footed Bats on Talus Slopes Paul R. Moosman, Jr.1,*, Daniel P. Warner1, R. Hardy Hendren1, and Micah. J. Hosler1 Abstract - Typical efforts to monitor bat populations in North America rely on winter hibernacula counts, but this method may be ill-suited for Myotis leibii (Eastern Small-footed Bat). Timing of reproduction, migration, and hibernation in this species also are poorly understood. We piloted novel techniques to monitor Small-footed Bats during the nonhibernation period, including catching bats in mist-nets placed directly on talus slopes, visually searching for roosting bats, surveying randomly distributed quadrats to estimate population size, and using skin temperature to study thermoregulation and seasonal activity. We efficiently documented bats with mist-nets and visual searches; the animals used crevices near the surface of talus slopes from early March until the end of October. Estimates from quadrats suggested one 3-ha talus slope had a maximum population of 196–343 bats. Use of torpor varied seasonally, but was similar between sexes. In mid-March, bats exhibited a hibernation-like pattern of torpor, hinting at the possibility that they may also overwinter on talus slopes. Monitoring of Small-footed Bats on rock outcrops during summer could resolve uncertainty about population trends. Thus, techniques described herein should be tested at suitable habitats in other parts of the range of Small-footed Bats. Introduction Wildlife managers have used winter surveys of caves and mines to gauge the status of many species of bats in North America, particularly those in the genus Myotis (O’Shea and Bogan 2003, Turner et al. 2011). Hibernacula surveys suggest that the fungal disease White-Nose Syndrome (WNS) has caused drastic population declines in several species of bats in North America (Turner et al. 2011). Mortality caused by WNS led the US Fish and Wildlife Service (USFWS) to review the status of Myotis leibii Audubon and Bachman (Eastern Small-footed Bat) and Myotis septentrionalis Trouessart (Northern Long-eared Bat) populations (USFWS 2013). Based mostly on data from hibernacula, the USFWS concluded that Northern Long-eared Bat populations had declined enough to warrant protection; whereas, evidence for declines among Eastern Small-footed Bats was insufficient (USFWS 2013). Unfortunately, quantifying trends in populations of Small-footed Bats from hibernacula surveys has probably been complicated by the fact that they often hibernate alone or in small groups and in microsites that are easily overlooked (Best and Jennings 1997, Chapin 2007, Krutzsch 1966). Some authors have even speculated the species may hibernate in rock outcrops (Johnson and Gates 2008, Saugey 1993), e.g., similar to Eptesicus fuscus Beauvois (Big Brown Bat) in the western 1Department of Biology, Virginia Military Institute, Lexington, VA 24450. *Corresponding author - moosmanpr@vmi.edu. Manuscript Editor: Joseph S. Johnson Northeastern Naturalist NENHC-2 P.R. Moosman, Jr., D.P. Warner, R.H. Hendren, and M.J. Hosler 2015 Vol. 22, No. 1 US (Neubaum et al. 2006). The hibernating habits of Small-footed Bats might explain why estimates of declines from WNS have been substantially lower in winter counts (12% decline) versus mist-net surveys in summer (68–84% declines) (Francl et al. 2012, Moosman et al. 2013, Turner et al. 2011). Although acoustic surveys have been used to study responses to WNS in other species of bats, none have included Small-footed Bats because they are infrequently detected and their calls are prone to misidentification (Brooks 2011, Dzal et al. 2011, Ford et al. 2011). Uncertainty over the status of Small-footed Bats is likely to continue unless alternative means to monitor their populations are developed. Monitoring populations during the non-hibernation period has rarely been attempted in North America because bats are generally dispersed on the landscape and difficult to count. However, a growing body of evidence suggests Small-footed Bats are concentrated at exposed rock outcrops during the non-hibernation period (Johnson and Gates 2008, Johnson et al. 2011, Saugey et al. 1993). Visually searching under rocks has also resulted in both accidental and intentional encounters with the species (Roble 2004, Whitby et al. 2013). These observations suggest monitoring Small-footed Bats may best be accomplished at rock outcrops, but techniques to do so have not been developed. We explored novel methods to study Small-footed Bats on talus slopes in the Blue Ridge Mountains of Virginia. Our goals were to test the feasibility of: (1) capturing bats in mist-nets placed directly on talus slopes, (2) visually searching for roosting bats, and (3) combining these methods with remote monitoring of skin temperature (Tsk) to infer timing of important life-history events, including migration or hibernation. We also explored the potential for using surveys of randomly distributed quadrats to estimate local population size. Methods Study sites We conducted our research at a 3.0-ha talus slope known as the Devil’s Marbleyard (hereafter, Marbleyard) in the James River Face Wilderness in Rockbridge County, 2 small (0.15-ha and 0.3-ha) talus slopes that were part of a network of rock outcrops in the Saint Mary’s Wilderness (hereafter, St. Mary’s) in Rockbridge County, and a 3.34-ha talus slope at Sherando Lake Recreation Area in Augusta County (hereafter, Sherando). Presence of Small-footed Bats at Sherando had been previously determined by mist-netting and radio-telemetry, but the species had not been documented at Marbleyard or St. Mary’s prior to the present study (P.R. Moosman et al., unpubl. data). We selected sites by examining SPOT satellite imagery in Google Earth Pro (Google, Inc., Mountain View, CA) for patches of exposed rock. Study sites were on primarily south-facing slopes and were composed of sedimentary rock ranging in size from boulders several meters wide to weathered fragments less than 0.25 m wide. We measured the non-forested area of each talus slope using the polygon tool in Google Earth Pro. Elevations ranged from 530–600 m at the bases to 700–800 m at the tops of the talus slopes. The surrounding forest was mixeddeciduous with overstory trees dominated by Quercus prinus L. (Chestnut Oak), Q. rubra L. (Northern Red Oak), Q. coccinea Münchhausen (Scarlet Oak), Pinus Northeastern Naturalist Vol. 22, No. 1 P.R. Moosman, Jr., D.P. Warner, R.H. Hendren, and M.J. Hosler 2015 NENHC-3 virginiana Miller (Virginia Pine), and Acer rubrum L. (Red Maple) (Mengkak and Castleberry 2008). Edges of the talus slopes had relict shoots of Castanea dentata Marshall (American Chestnut). Visual searches We conducted timed diurnal visual searches for roosting bats at Marbelyard on 22 visits from 5 June 2013 to 30 March 2014, on 4 visits to Sherando from 18 July to 25 October 2013, and on 2 visits to St. Mary’s on 16 and 24 July 2013. We quantified search effort in person-hours (e.g., 1 person-hour = 1 person searching for 1 h, or 2 people searching for 0.5 h). Searching ceased when at least 1 bat was located or after 2.5 person-hours if no bats were located. Searches were conducted by 1–3 of the authors using LED lights to inspect crevices for roosting bats. While walking on talus slopes, we wore helmets and chose our footsteps carefully to avoid stepping on unstable rocks or potential roosts. These precautions were particularly necessary on portions of talus slopes with small rocks because they tended to be the least stable. We captured by hand bats that were alone or in small groups (composed of 1 adult female and 1–3 juveniles) by coaxing them out of the crevice using 2 flexible 1.0-m-long vinyl-coated wire probes. To minimize disturbance to colonies, we did not capture bats in maternity colonies (>1 adults). Mist-netting We deployed mist nets with 38-mm mesh in 2 manners. Because Marbleyard lacked corridors traditionally considered suitable for surveys with mist-nets, we placed two 12-m-long x 3-m-high nets end to end directly on the talus slope (hereafter, each pair will be considered a single net). We placed nets perpendicular to the forest edge with one end against the tree-line and the other end extending toward the center of the boulder field. Nets were attached to light-weight telescoping aluminum poles that were anchored to the substrate by guy ropes and were operated from 15 min before sunset until 1.25 h after sunset to capture bats that had recently emerged from crevices on the slope. We conducted sampling in this manner on 4 June, 26 June, and 24 September. At Sherando, we placed mist nets in traditional arrangements of 6–9-m-long nets stacked vertically to block a stream corridor adjacent to the talus slope (hereafter, each stacked set of nets is considered a single net). We placed 2 nets >30 m apart and operated them 15 min before sunset until 4 h after dark on 13 and 23 September. We removed the captured bats from the net; weighed them to the nearest 0.1 g using a spring scale (Pesola AG, Baar, Switzerland); determined their sex, age, and reproductive state; and placed a numbered aluminum band (Porzana Limited, East Sussex, UK) on the forearm (left for females, right for males) of each bat before release. Handling of bats followed Sikes et al. (2011). Quantifying populations We assessed population density of Small-footed Bats at Marbleyard by surveying random quadrats. Because no studies had reported use of talus slopes by Smallfooted Bats in closed-canopy forest, and crevices in this habitat at our study site Northeastern Naturalist NENHC-4 P.R. Moosman, Jr., D.P. Warner, R.H. Hendren, and M.J. Hosler 2015 Vol. 22, No. 1 were filled with leaf litter, we only considered as available roosting habitat parts of the slope that appeared non-forested on SPOT satellite images. We sampled occurrence of bats in available habitat by searching all crevices in 13 randomly distributed, circular 78.5-m2 quadrats (i.e., 3.4% of the talus slope). We determined quadrat placement by overlaying a grid with cells representing 10 m x 10 m onto an aerial image of the site and created a pool of 284 points at the intersections of grid lines, each marking the center of a potential quadrat. Quadrats were selected randomly from this pool with SPSS version 20.0 (IBM Corp., Armonk, NY) and observers navigated to the center of each with a Triton 500 GPS device with 3–5-m accuracy (Magellan, Santa Clara, CA). We used a measuring tape to define a 5-mradius circle as the boundary of the quadrat, and 2 of the authors searched every crevice in the quadrat, recording the number of bats and suitable crevices present. We considered crevices suitable if they were large enough for a Small-footed Bat to fit inside (i.e., some portion ≥0.75 cm wide) and were ≤4 cm wide at the narrowest (the widest roosting cavity we have documented; P.R. Moosman, pers. observ.). We marked crevices with colored chalk to prevent mistakes during counting. Because Eastern Small-footed Bats often use a different roost each day, make consecutive movements of less than 50 m (Johnson and Gates 2008; Johnson et al. 2011; P.R. Moosman, pers. observ.), and all quadrats could not be surveyed in the same day, we surveyed quadrats in 3 groups (on 2, 5, and 12 July 2013) that were >50 m apart to reduce chances of recounting the same bats. We explored 2 methods to estimate population. In the most conservative method, we calculated population estimates by scaling up the 95% confidence limits for the number of bats counted to the entire area of talus slope. In the second method, we made population estimates by multiplying a pooled occupancy rate (proportion of suitable crevices with bats) by the 95% confidence limits of the projected number of crevices on the entire slope. These methods were meant to represent crude and ecological estimates of population density, respectively. We based confidence limits in both methods on the Poisson distribution (Zar 1999). Monitoring of skin temperature A temperature-sensitive 0.24-g radio transmitters (LB-2XT, Holohil Systems Ltd., Carp, ON, Canada; representing 4–6% of body weight) was used to study Tsk and activity of a subset of 16 bats (9 males, 7 females) at Marbleyard and Sherando. We radio-tagged 3 females and 1 male bat twice as opportunity allowed. This tagging provided data from 3 scrotal and 6 non-scrotal males and 1 pregnant, 3 lactating, and 5 non-reproductive females. We collected data longitudinally over the study by radio-tagging 1–2 bats on average every 10.8 ± 0.5 days. Skin temperature (Tsk) was recorded every 2 min over the life of each transmitter using an SRX-DL data-logging receiver (Lotek Wireless, Inc., New Market, ON, Canada) at each site, attached to a 6-m-tall omni-directional antenna and a 3-element directional antenna, powered by a 12v deep-cycle battery and 2 Solaris 26 photovoltaic arrays (Brunton Outdoor, Inc., Riverton, WY). We used data from radio-transmitters to assess if bats were present at the site (i.e., within range of the data-logger) and whether they Northeastern Naturalist Vol. 22, No. 1 P.R. Moosman, Jr., D.P. Warner, R.H. Hendren, and M.J. Hosler 2015 NENHC-5 were active or torpid. Data-loggers typically detected radio-transmitters of bats roosting less than 100 m away; therefore, we assumed data were from bats on or near the talus slopes. We defined torpor as any Tsk below the lowest active Tsk recorded at emergence, as was the standard in previous studies (Cryan and Wolf 2006, Solick and Barclay 2006). Active Tsk in our study ranged from 30.1 °C to 38.1 °C; thus, we defined torpor as Tsk < 30 °C. Maximum Tsk while roosting (usually between noon and emergence) also was recorded. Hourly air temperature (Ta) was recorded using a Thermocron iButton (NexSens Technology, Inc., Fairborn, OH) placed 2 m above the ground in a shaded location in the forest below each talus slope as a basis for comparison. Work was conducted under a collecting permit (#048316) issued by the Virginia Department of Game and Inland Fisheries, and approved by the Animal Subjects Committee at the Virginia Military Institute. We quantified the number of days between the first and last instance each bat was detected by the data-logger, as well as the number of days bats spent absent or out of range. We pooled data for each bat that was radio-tagged twice and then assessed potential gender-differences between these variables using two-tailed independent-sample t-tests. Seasonal variation in the above variables was assessed using Pearson bivariate correlations, with date expressed as a Julian number. We quantified patterns of Tsk using incidence of torpor (the ratio of days bats were detected in torpor versus the number of days they were detected at active Tsk). To ensure data were not collected from transmitters after they had been shed by bats, we only considered bouts of torpor as valid if followed by an arousal to active Tsk. We assessed effects of season (Julian day) on proportion of days bats were recorded in torpor using a linear regression with incidence of torpor as the dependent variable and start date of each bat’s monitoring period as the independent variable. Statistical analyses were performed using SPSS with α of 0.05. All results are reported as mean ± se, unless noted otherwise. Results Across sites, timed visual searches resulted in the discovery of an average of 3.1 ± 1.1 bats per person-hour of searching between 5 June and 3 September (Fig. 1). During this period, we documented bats in 100% of searches at Marbleyard (6 visits), St. Mary’s (2 visits), and Sherando (2 visits). We documented bats more sporadically between 20 September and 29 October (40%, or 2 of 5 visits at Marbleyard and Sherando combined). We discovered a total of 27 bats in 23 roosts during timed visual searches, including: 20 roosts with solitary bats, 2 roosts with 2 bats, and 1 roost with 3 bats. Instances of bats roosting together included a pair of adults of unknown sex on 5 June, a female roosting with a 3.5- g juvenile on 16 July, and a trio composed of a lactating female with 2 volant 4.25-g juveniles on 18 July. We encountered an additional 8 roosts by chance while setting up mist nets or walking to quadrats to conduct population estimates, including: 5 encounters with solitary bats, 1 with 2 adults, and 2 with maternity colonies. We discovered the first colony on 15 June when bats were heard vocalizing from a series of crevices in a Northeastern Naturalist NENHC-6 P.R. Moosman, Jr., D.P. Warner, R.H. Hendren, and M.J. Hosler 2015 Vol. 22, No. 1 6-m-tall x 7-m-wide boulder. Size of this colony was unknown. Vocalizations lead to the discovery of another maternity colony on 5 July, which had ~20 bats congregating in direct sunlight at the mouth of a large vertical crevice in a >3-m-wide boulder. In addition to finding Small-footed Bats in their roosts, we saw one (later determined to be a post-lactating female) flying during the day . Mist nets on the talus slope captured 13 Small-footed Bats, with an average of 4.3 ± 2.1 bats per net-night (or 3.8 ± 1.8 per hour of sampling), not including recaptures. We captured all of these bats less than 10 m from the forest edge, on the up-slope side of nets an average of 24 ± 2 min after sunset (range = 14–48 min after sunset). Bats captured in mist-nets on the talus slope included 9 non-scrotal adult males and 4 adult females (2 pregnant, 1 lactating, 1 post-lactating, and 1 with no evidence of reproduction). We recaptured 2 bats (a male first caught on 3 June and a female first caught on 26 June) on our final mist-netting attempt. One scrotal adult male Small-footed Bat was captured in mist-nets at Sherando on 13 September. Data from mist-nets and visual searches combined resulted in the following observations (first and last dates): pregnancy (4–26 June), lactation (26 June–18 July), maternity colonies and small mother-pup groups (15 June–18 July), nonreproductive adult females (29 August 2013–11 March 2014), and scrotal males (3 September–29 October). Additionally, we made single observations of a postlactating female on 16 July and two 4.25-g volant juveniles on 18 July. The last date we documented bats in autumn was 29 October. We failed to detect bats during 6 searches between 6 November and 2 March. Encounters with bats resumed on 11 and 23 March. Surveys of random quadrats at Marbleyard resulted in the discovery of 6 bats out of 337 crevices searched. We estimated that the entire talus slope had 8873–11,018 suitable crevices, and calculated the size of the population to be 48–343 bats when we used the crude estimate and 158–196 bats using the ecological estimate (95% CI). Figure 1. Phenology of Eastern Small-footed Bats on talus slopes in Virginia, inferred from visual searches for roosting bats and bats captured in mist-nets. Bars represent the number of bats observed relative to visual search effort. Northeastern Naturalist Vol. 22, No. 1 P.R. Moosman, Jr., D.P. Warner, R.H. Hendren, and M.J. Hosler 2015 NENHC-7 Of the 16 bats radio-tagged, 11 were detected by the data-logger every day, 3 went undetected for 2–7 days (3.3 ± 1.5 days), and 2 were never detected. The time elapsed between the first and last instances bats were detected (5.1 ± 0.9 days per radio-transmitter) and the number of days they went undetected (1.0 ± 0.5 days per radio-transmitter) was similar between sexes (P = 0.36, P = 0.73, respectively) and showed no discernable seasonal pattern (P = 0.14 and P = 1.0, respectively). Time of year had a significant negative effect on incidence of torpor, with use of torpor greatest in spring and lowest in autumn (F1,15 = 10.28, P = 0.006; Fig. 2). Maximum active Tsk was 35.7 ± 1.0 °C, whereas Tsk when roosting reached 1.9 ± 0.6 °C above active Tsk. Bats typically exhibited a daily Tsk pattern from June to October characterized by torpor while in the roost, during which Tsk mimicked Ta. That is, Tsk gradually rose from a minimum Tsk near dawn to a maximal Tsk after noon, before declining until bats aroused and emerged from the roost at sunset (Fig. 3). In contrast, bats in March of 2014 remained in a steady state of relatively deep torpor (mean Tsk = 13.8 ± 0.3 °C) for >2 days (perhaps >4 days), interrupted by ~1 h-long periods of arousal to active Tsk (Fig. 3). During the same period, mean Ta was 3.8 ± 2.3 °C, with daily minima ranging from 1.5 to -6.0 °C Figure 2. Seasonal changes in the incidence of torpor, expressed as the ratio of the number of days in which torpor was documented versus the number of days in which bats exhibited active skin temperature. Data were from 8 males (hollow symbols) and 7 females (solid symbols) from summer to autumn of 2013 and spring of 2014. The center line represents the trend, and the upper and lower lines represent the 95% confi dence intervals. Northeastern Naturalist NENHC-8 P.R. Moosman, Jr., D.P. Warner, R.H. Hendren, and M.J. Hosler 2015 Vol. 22, No. 1 Discussion Our results suggest that surveying for Eastern Small-footed Bats on talus slopes is highly effective. Bats were efficiently encountered in visual searches and by placing mist nets directly on talus slopes during summer. The efficiency of both methods suggests either is preferable over the customary means of placing mistnets on roads or permanent bodies of water (unless perhaps such features occur particularly close to suitable rock outcrops). The next-best published capture success was only ~1 Small-footed Bat per net-night (or 0.25 bats per hour of sampling) using mist-nets placed on forest edges and roads 10–500 m from a boulder-covered dam where bats roosted (Moosman et al. 2013). Francl et al. (2012) reported much lower rates of capture (less than 0.1 Small-footed Bat per net-night) using standard mist-net Figure 3. Skin temperature of 2 Eastern Small-footed Bats (solid symbols) illustrating differences between patterns in summer (A) and those in early spring (B). Air temperature in the shade near the talus slope (hollow symbols) is shown for comparison. Isolated solid symbols are erroneous readings by the data-logger. Northeastern Naturalist Vol. 22, No. 1 P.R. Moosman, Jr., D.P. Warner, R.H. Hendren, and M.J. Hosler 2015 NENHC-9 protocols that do not target rock outcrops, i.e., those designed for Myotis sodalis Miller and Allen (Indiana Bat). We note that in our study, bats were caught immediately after sunset, apparently as they traveled down the edge of the talus slope. Therefore, researchers planning to use the technique we outline here should ensure nets are deployed before dusk and attempt to place them perpendicular to the forest edge or other terrain features likely to funnel bats. Mist-nets placed on the talus slope resulted in the greatest number of bats captured per hour of sampling (not including time to set up nets); thus, we preferred this method when attempting to acquire several bats to radio-tag. However, visual searches were preferable for simply confirming that bats were present at a site. The effort needed to visually locate Small-footed Bats during the present study was similar to that reported by Whitby et al. (2013) at rock-outcrops in Illinois, except we rarely needed to move rocks in order to search crevices. It should be noted that search effort needed to locate bats appeared to vary between talus slopes as a function of boulder size. Sherando had the smallest boulders (therefore the greatest number of crevices) and required the most time to survey. Visual searches also generated some novel observations, e.g., bats making brief flights between roosts during the day, and bats apparently basking in sunlight outside the entrances to roosts. Basking of course is a common behavior in many species of animals, but it has been rarely documented in bats (see Slough 2009). The population estimates we derived from random surveys are particularly promising. Although the technique should be refined, we present these data to stimulate a much needed discussion. Both of our estimates indicate the population at Marbleyard was small compared to summer populations of other bat species, but still greater than the largest numbers of Small-footed Bats reported from hibernacula surveys (Johnson and Gates 2008, Turner et al. 2011). We suspect the true population size at Marbleyard was between the totals which we derived using crude and ecological estimates. Differences between the two methods of estimating population size are important to consider. The crude method of estimation did not take into account variation in availability of potential crevices and it was negatively affected by the fact that many quadrats contained no bats (i.e., quadrat data were zero-inflated). The ecological estimate accounted for variation in availability of suitable crevices, and likely was less affected by zero-inflation, but it unrealistically assumed no variation in occupancy rates. These findings suggests population estimates can be improved by (1) quantifying variation in occupancy rates and (2) reducing zero-inflation (e.g., by increasing quadrat size and conducting surveys during parts of the year when females roost alone). Other ways to improve modeling of error also are possible and should be explored (Dupuis et al. 2011). Combined observations indicate both sexes were present on the talus slopes throughout the study. Maternity season occurred from early June to mid-July, and scrotal males were observed from early September to mid-October, perhaps suggesting mating occurs on talus slopes. Visual surveys from November through the winter failed to detect bats, indicating they either migrated to hibernacula elsewhere or moved into microsites on the talus slopes that we could not survey effectively Northeastern Naturalist NENHC-10 P.R. Moosman, Jr., D.P. Warner, R.H. Hendren, and M.J. Hosler 2015 Vol. 22, No. 1 (i.e., deep crevices or rip-rap caves). Bats appeared to have returned to crevices near the surface by early March. These data generally agree with what little information about the phenology of Small-footed Bats has been published (see Best and Jennings 1997, Johnson and Gates 2008). We were surprised that the incidence of torpor in bats we studied was similar between sexes and that use of torpor declined from spring through autumn. Studies of other bats species in temperate regions have reported differences in thermoregulatory patterns based on sex or reproductive status (Cryan and Wolf 2003, Solick and Barclay 2006), and more frequent use of torpor in spring and autumn than in summer (Becker et al. 2013, Wojciechowski et al. 2006). These discrepancies might be resolved with additional data, including for bats later into autumn, but it is also possible the thermal properties of talus slopes allow unique thermoregulatory opportunities for Small-footed Bats. The talus slopes we studied provided particularly warm microclimates, relative to Ta. During summer and autumn daily Tsk often began ~3 °C or more above Ta in the morning and rose to 11 °C or more above Ta in the warmest part of the afternoon. Furthermore, Tsk during the day sometimes reached 40 °C and typically exceeded that recorded at night when bats were presumably flying. Roosting in such conditions could minimize the need for active arousals, but perhaps also increase costs from evaporative water loss. Indeed, other authors have suggested Small-footed Bats select sites near water (Johnson et al. 2011). Although we did not observe bats at our study sites in winter (including during searches of 3 rip-rap caves), the question of whether Small-footed Bats hibernate in talus slopes remains unanswered. Skin temperatures of 3 bats captured from particularly deep crevices in March resembled those of hibernating bats. We captured these bats after brief warm spells. Two were torpid when discovered and a 3rd bat was sunning itself outside its roost but crawled back inside as we approached. Two cold fronts arrived less than 24 h after bats were released, bringing low temperatures of -6 °C and covering the talus slope with snow. Skin temperatures were remarkably stable during this time despite drastic fluctuations in Ta and they were within the range of temperatures expected in caves in eastern North America during winter, including those used by Small-footed Bats (Moore and Sullivan 1978, Swezey and Garrity 2009, Webb et al. 1996). The bats in our study only aroused to active Tsk for ~1-h long periods in March, a pattern that was distinct from the daily pattern of torpor and arousals demonstrated during summer and autumn. We suspect bats in March remained in the crevices from which they were captured, but it is also possible they moved to other crevices during arousals. In conclusion, Eastern Small-footed Bats are more accessible than has commonly been assumed, and monitoring their populations on talus slopes is one likely solution to the uncertainty about population trends described in the USFWS (2013) finding. Talus slopes are not the only habitats the species occupies, but they are abundant in the Appalachian Mountains and they are detectable in remote-sensing imagery (O’Keefe and LaVoie 2010, Whitby et al. 2013). Use of thermal refugia on talus slopes in spring further supports the notion that Eastern Small-footed Bats could hibernate outside of caves and mines. This situation Northeastern Naturalist Vol. 22, No. 1 P.R. Moosman, Jr., D.P. Warner, R.H. Hendren, and M.J. Hosler 2015 NENHC-11 would support the hypothesis that Small-footed Bats are at lower risk of mortality from WNS (Langwig et al. 2012), but it also would raise doubts about the efficacy of using cave and mine surveys to monitor their populations. Identifying techniques to monitor populations of Eastern Small-footed Bats should be a major conservation priority. In particular, the methods described herein should be tested at suitable habitats in other parts of the Eastern Small-footed Bat’s range and, if determined to be reliable, used to begin monitoring. Acknowledgments Funding was provided by the Virginia Department of Game and Inland Fisheries through a Wildlife Restoration Grant from the US Fish and Wildlife Service, and the Virginia Military Institute’s Center for Undergraduate Research. We thank the US Forest Service for allowing us to conduct this study. Additionally, we are indebted to R. Reynolds, K. Powers, R. Humston, D. Wright, K. Simms, H. Thomas, J. Huth, E. Hill, P. Burke, and W. Ford for the help they provided with various aspects of the research. Literature Cited Becker, N.I., M. Tschapka, E.K.V. Kalko, and J.A. Encarnação. 2013. Balancing the energy budget in free-ranging male Myotis daubentonii bats. 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