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Bat Species Diversity in the Boreal Forest of Northeastern Ontario, Canada
Stephen C. Mills, Amanda M. Adams, and R. Dean Phoenix

Northeastern Naturalist, Volume 20, Issue 2 (2013): 309–324

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2013 NORTHEASTERN NATURALIST 20(2):309–324 Bat Species Diversity in the Boreal Forest of Northeastern Ontario, Canada Stephen C. Mills1,*, Amanda M. Adams2, and R. Dean Phoenix1 Abstract - In southern Ontario, Canada, the range and distribution of bats is well known, but their activity in the northeastern part of the province (north of 47°N, east of 85°W) is poorly documented. Using acoustic sampling, we documented the occurrence of six species of bats in the boreal forest of northeastern Ontario: Eptesicus fuscus (Big Brown Bat), Lasiurus borealis (Eastern Red Bat), L. cinereus (Hoary Bat), Myotis lucifugus (Little Brown Bat), M. septentrionalis (Northern Long-eared Bat), and Lasionycteris noctivagans (Silver-haired Bat). Hoary Bats were recorded more frequently than all other species. Little Brown Bats were second-most frequently recorded, and the remaining four species were encountered (mean number passes/hour) significantly less often. Our records are the most northerly for Big Brown Bats in this part of Ontario. Although the other species were expected in this area, this is the first study to identify and confirm the bats present in the boreal forest of northeastern Ontario. This new information will contribute to efforts to conserve biodiversity in the province and may inform future studies or monitoring programs associated with the spread of white-nose syndrome in Ontario. Introduction There are many gaps in knowledge regarding species at the northern limits of their range, including basic information such as presence, and these gaps can impact decisions concerning conservation and management. Knowledge of bats especially is sparse in the north, but this information has become vital with the discovery of white-nose syndrome (WNS) in Ontario in 2009 (Turner et al. 2011). White-nose syndrome is an infectious disease caused by a fungal pathogen that was first discovered in the northeastern United States in 2006; the disease causes substantial mortality in hibernating bats and ultimately results in significant population decline, to the point where local extinction of one of more species may occur (Frick et al. 2010). Regional data related to the diversity of bat species will help inform conservation efforts because this new threat has the potential to drastically change regional communities (Timpone et al. 2011). The importance of species diversity is recognized in Ontario’s Biodiversity Strategy (Ontario Ministry of Natural Resources 2005), but conserving biodiversity at the species level is difficult without knowing which species inhabit a particular region. 1Northeast Science and Information Section, Ontario Ministry of Natural Resources, 5520 Highway 101 East, South Porcupine, ON P0N 1H0, Canada. 2Department of Biology, Western University, London, ON N6A 5B7, Canada. *Corresponding author - 310 Northeastern Naturalist Vol. 20, No. 2 Eight species of bats are known from Ontario (Dobbyn 1994, van Zyll de Jong 1985), but little information exists about their distribution in northeastern Ontario (north of 47°N, east of 85°W). Although extensive range maps exist for these species, they are often extrapolated from a few confirmed occurrences (van Zyll de Jong 1985). Historic information exists for Myotis lucifugus LeConte (Little Brown Bat) near Timmins, ON, the closest city to our study area (Fig. 1; Fenton 1970), and the Atlas of Mammals of Ontario (Dobbyn 1994) also reports the presence of the Little Brown Bat and M. septentrionalis Trouessart (Northern Long-eared Bat) within 100 km of this location. In addition, Dobbyn (1994) states that Lasionycteris noctivagans LeConte (Silver-haired Bat), Lasiurus borealis Müller (Eastern Red Bat), and L. cinereus Palisot de Beauvois (Hoary Bat) can be found throughout Ontario. We expected these five species to be present in this part of northeastern Ontario. Furthermore, records for the Eastern Red Bat, Hoary Bat, and Silver-haired Bat from locations greater than 200 km north of our study area suggest that it is within the known range of these species (Dobbyn 1994). The closest records for Eptesicus fuscus Palisot de Beauvois (Big Brown Bat) are greater than 100 km south of our study site (Dobbyn 1994), but this species has been documented farther north in northwestern Ontario (van Zyll de Jong 1985), Saskatchewan (Kalcounis et al. 1999), and Alaska (Parker et al. 1997). These locations are all within the boreal forest region, a vast area dominated by coniferous forests interspersed with wetlands. The boreal forest is the largest forest region in Canada and stretches from the Yukon in the west to Newfoundland in the east (Rowe 1972). This forest region represents the northern extent of distribution of many species of bats (van Zyll de Jong 1985) and is important habitat for other wildlife (e.g., landbirds; Blancher 2003). Published reports for Perimyotis subflavus F. Cuvier (Tricolored Bat) and Myotis leibii Audobon and Bachman (Eastern Small-footed Bat) indicate that these species are no closer than 200 km south of our study area. New research, however, suggests that the Tricolored Bat occurs farther north than previously documented. Based on data from stable isotopes, Fraser et al. (2012) postulate that Tricolored Bats spend the summer as far north as the southern tip of James Bay (Fig. 1) In the boreal forest of northern Alberta, Patriquin and Barclay (2003) examined the effects of timber harvesting on bats but documented only three species (Little Brown Bat, Northern Long-eared Bat, and Silver-haired Bat). They suggested that other species (e.g., Big Brown Bat and Hoary Bat) not captured or otherwise detected during their study may have been present. Published range maps for these additional species (van Zyll de Jong 1985) include the study area of Patriquin and Barclay (2003), supporting our assertion that the few documented occurrences for some species of bats may have caused inaccurate portrayals of their distributions. Extensive work to investigate distribution and diversity of bats in other northern jurisdictions has been completed (Grindal et al. 2011, Parker et al. 1997), but studies in Ontario have generally focused on 2013 S.C. Mills, A.M. Adams, and R.D. Phoenix 311 the Little Brown Bat (Dubois and Monson 2007; Fenton 1969,1970) or on areas south of the boreal forest (Jung et al. 1999). This study will provide information on both the diversity and relative activity of bats in our project area and serve as an important baseline against which we may assess the potential spread and impact of WNS on bat activity. Since the discovery of WNS in Ontario in 2009, the disease has been documented in bats in many regions of the province, including locations approximately 100 km east of our study area during winter 2010 and less than 50 km north of our study area during winter 2011. These locations represent the most northerly detection of WNS in Ontario (Turner et al. 2011). The disease is likely to have a dramatic negative effect on several species of bats in Ontario, including the Little Brown Bat, Northern Long-eared Bat, and Tricolored Bat (Turner et al. 2011). A recent emergency assessment by the Committee on the Status of Endangered Wildlife in Canada (2012) concluded that the Little Brown Bat, Northern Long-eared Bat, and Tricolored Bat are endangered. The objectives of our study were to identify the species of bat in clearcut areas and along edges of patches and intact forest in northern Ontario and examine differences in relative activity among species, using passive acoustic sampling. We hypothesized that all species previously documented or predicted to occur in this area (van Zyll de Jong 1985) would be present. We also predicted that we would detect the Big Brown Bat and Tricolored bat, because of published evidence suggesting that they occur farther north than currently indicated (Fraser et al. 2012, van Zyll de Jong 1985). Based on the mixed composition of the forest and essentially contiguous forest matrix, we expected that species such as the Little Brown Bat, a habitat generalist (Fenton and Barclay 1980), and the Northern Long-eared Bat, a forest specialist (Caceres and Barclay 2000, Henderson and Broders 2008, Henderson et al. 2008, Hogberg et al. 2002), would both be highly active at edge sites and less active at clearcut sites. We also predicted that activity of the Hoary Bat, Eastern Red Bat, and Silver-haired Bat would be highest in clearcut areas because these species are better suited to forage in open habitats (Lacki et al. 2007, Owen et al. 2004). Methods Field site description We conducted our study within a forestry research area of approximately 528 ha (384 ha harvest area and 144 ha residual, unharvested area) south of Timmins, ON, Canada (N48°28'34",W81°19'42"; Fig. 1) in the boreal forest region of Ontario (Rowe 1972). The area has flat-to-rolling topography and a mixed-forest composition. The most abundant species of deciduous trees are Betula papyrifera Marsh. (Paper Birch) and Populus tremuloides Michx. (Quaking Aspen) (Forestry Research Partnership 2008); the most common species of conifers are Thuja occidentalis L. (Eastern White Cedar), Picea mariana (P. Mill.) B.S.P. (Black Spruce), Picea glauca (Moench) Voss (White Spruce), and Abies balsamea (L.) 312 Northeastern Naturalist Vol. 20, No. 2 P. Mill. (Balsam Fir). Ambient temperatures are highest in July, with an average daily minimum of 10.5 °C and average daily maximum of 24.2 °C; mean annual precipitation is 831.3 mm (Environment Canada 2011). Sampling points were located in 3 site-types: clearcut areas, edges of patches (patch-edge), and edges of intact forest (forest-edge). Clearcuts were defined as harvested areas having a residual retention of approximately 25 trees/ha. Patches were separated from intact forest by at least 30 m and were at least 0.25 ha but not Figure 1. Map of Ontario, Canada, showing the area where acoustic sampling of bats was conducted. Light shading indicates the extent of the boreal forest (as described in Rowe 1972). Hatched area represents the distributional range of the Big Brown Bat (from van Zyll de Jong 1985). 2013 S.C. Mills, A.M. Adams, and R.D. Phoenix 313 greater than 2.0 ha, whereas intact forest was defined as not previously disturbed, primary forest. No permanent, standing or flowing water was located within the study area, but water was available in small ephemeral pools and low-lying areas. We did not quantify the area or number of these features. Field techniques We sampled 8 locations within each of the 3 site-types, for a total of 24 sampling sites, from 24 June to 3 August 2009. Each site was surveyed for 1 (n = 17 sites), 2 (n = 5), 3 (n = 1), or 4 (n = 1) nights. From 18 June to 28 July 2010, we surveyed 8 patch-edge sites and 8 forest-edge sites, but only one of the clearcut sites, for a total of 17 sampling sites; each site-type was surveyed for 2 (n = 10 sites), 3 (n = 6), or 4 (n = 1) nights. At each site, echolocation calls were recorded using a full-spectrum ultrasonic detector (batcorder 2.0, ecoObs, Nuremberg, Germany). On all sampling nights, we deployed two detectors, each at a different location. Detectors were attached to trees that were approximately 15–20 cm in diameter at 1.2 m above the ground; the microphone was oriented parallel to the ground or angled slightly downward, to prevent water from falling on the microphone. We cleared surrounding vegetation for 1–2 m around the microphone to minimize interference. Detectors were programmed to record whenever an echolocation call was detected within the fixed recording period of 2200 hours (2009: 29–61 min after sunset; 2010: 30–52 min after sunset) to 0400 hours (2009: 84–123 min before sunrise; 2010: 83–115 min before sunrise). We used weather data from Timmins, ON, the closest weather station (37 km) to our study area (Environment Canada 2011). We recognize that meteorological factors can affect activity levels of bats (Erickson and West 2002) and eliminated sampling nights from our analyses during which mean nightly temperature was less than 10 °C, total duration of precipitation (rain, rain showers, or drizzle) was >4 h, or if precipitation occurred for the entire first 2 h of our sam pling period. Data analysis We identified acoustic recordings to species using quadratic discriminant function analysis (DFA). The DFA compared our unidentified data to a training dataset and classified each call based on 11 call parameters that were extracted by the automated detection feature of callViewer18 (Skowronski and Fenton 2008). CallViewer is a custom echolocation sound-analysis program written with MATLAB (The MathWorks, Nadick, MA). The 11 call parameters were minimum frequency (Fmin), maximum frequency (Fmax), duration, frequency of most energry (FME), 10th percentile of energy (F10), 60th percentile of energy (F60), 90th percentile of energy (F90), median frequency slope (dFmedian), median energy slope (dEmedian), median frequency smoothness (sFmedian), and median energy smoothness (sEmedian). The training dataset consisted of known echolocation calls for seven species of bats present in Ontario; it did not include the Eastern Small-footed Bat because 314 Northeastern Naturalist Vol. 20, No. 2 we cannot distinguish its echolocation calls from those of the Little Brown Bat (Table 1). The training dataset was compiled by biologists at Western University from various locations over numerous years. All reference recordings came from free-flying bats, with search-phase echolocation calls outside of known roosts or at foraging sites where species and individual bats were identified unambiguously. No reference recordings came from hand-released individuals. We always analyzed the harmonic with most energy within each call, which was the fundamental harmonic for all species. We used only one call from each individual bat to eliminate pseudoreplication in the training dataset. Our data were filtered to eliminate noise and weak or fragmented calls, because the DFA is not capable of assigning “unknown” classifications. Cross-validation was run to determine the classification accuracy of the training dataset (Table 1). All species were weighted equally in the DFA. We used R, version 2.13.1 (R Development Core Team 2011) for all acoustic analyses. Additionally, 41% of the files that contained bat calls were visually validated as additional confirmation of the accuracy of the DFA, and calls that could not be visually identified to species were classified as “unknown”. To account for differences in the number of sampling nights among sites, we calculated bat activity as mean number of acoustic files per hour (hereafter referred to as passes/hour). Each acoustic file was counted as a pass because of the nature of the trigger algorithm on batcorders, with most (98%) acoustic files containing only a call sequence (>2 calls) from a single individual of one species. We determined mean number of passes/hour for each species by site-type combination, which we then transformed using log(passes/hour + 1)0.25. Because data were still non-normal, we used the Kruskal-Wallis test in R, version 2.13.1 (kruskal.test; R Development Core Team 2011) to look for significant differences in transformed passes/hour among species, among site-type, and among species within each site-type and conducted post-hoc tests with kruskalmc in the pgirmess package, version 1.5.2 (Giraudoux 2011). Multiple pairwise comparisons using kruskalmc determine which groups are significantly different (P < 0.05). Pairwise differences are significant when Table 1. Classification accuracy (%), representing the proportion of known calls in the training dataset correctly identified to species with quadratic discriminant function analysis, using crossvalidation. Species known from OntarioA Number of reference calls Classification accuracy (%) Big Brown Bat 50 78 Eastern Red Bat 58 88 Hoary Bat 52 90 Little Brown Bat 50 90 Northern Long-eared Bat 33 82 Silver-haired Bat 50 94 Tricolored Bat 42 93 AClassification did not include the Eastern Small-footed Bat, due to difficulty in distinguishing it acoustically from the Little Brown Bat. 2013 S.C. Mills, A.M. Adams, and R.D. Phoenix 315 pairs have an observed value that is statistically different from a critical value. We also calculated the proportions of total sites and 95% confidence intervals where each species was encountered, as a relative measure of occurrence for the study area. These statistical analyses were conducted with SYSTAT version 13 (Systat Software, Inc., Chicago, IL). Results We recorded 3607 files (passes), and 1490 were visually validated. We were unable to identify 31 (2%) of the visually validated files with bat calls to species and excluded them from further analyses. The remaining 3576 passes with bat activity (2009: 2273 passes, 2010: 1303 passes), included 24,131 individual echolocation calls (2009: 15,907 calls, 2010: 8224 calls) that we were able to identify to species (Table 2). We confirmed the presence of 6 species of bats: Big Brown Bats, Eastern Red Bats, Hoary Bats, Little Brown Bats, Northern Long-eared Bats, and Silver- haired Bats. Little Brown Bats occurred at the highest proportion of sites (21 sites, 87.5%), and Big Brown Bats at the lowest (12 sites, 50.0%), whereas all other species occurred at an intermediate proportions of sites (Table 2). We speculated that since Eastern Small-footed Bats were uncommon in Ontario (Dobbyn 1994, van Zyll de Jong 1985), especially at the northern extent of their range, and that misidentification of these bats as Little Brown Bats occurred rarely, if at all, and would not affect our estimates of relative activity levels for Little Brown Bats. Bat activity was not equal among site-types or species. Overall, bats were significantly more active (mean number passes/hour ± SE) at patch edge sites (2.10 ± 0.68) than at clearcut sites (0.21 ± 0.07) (H2 = 12.08, P = 0.0024; Fig. 2A). Hoary Bats (3.75 ± 1.22) and Little Brown Bats (1.37 ± 0.54) had significantly higher activity levels than all other species (H5 = 107.01, P < 0.001; Fig. 2B). Hoary Bats were significantly more active at clearcut sites than all species except Little Brown Bats, whereas Little Brown Bats had significantly higher activity levels than Silver-haired Bats at the same sites (H5 = 40.25, P < 0.001; Fig. 3). Within the forest-edge site-type, activity levels of Little Brown Bats, Hoary Bats, and Northern Long-eared Bats were not significantly different from each other, Table 2. Summary of passes and number of calls, by species of bat, for 2009 and 2010, and the proportion (95% C.I.) of sampling sites at which each species was detected. 2009 2010 Species Passes Calls Passes Calls Proportion Sites (95% C.I.) Big Brown Bat 52 312 18 94 0.500 (0.204) Eastern Red Bat 19 135 76 939 0.667 (0.193) Hoary Bat 1867 11,701 782 2473 0.833 (0.152) Little Brown Bat 254 3097 372 4312 0.875 (0.135) Northern Long-eared Bat 38 373 29 307 0.667 (0.193) Silver-haired Bat 43 289 26 99 0.583 (0.201) 316 Northeastern Naturalist Vol. 20, No. 2 Figure 2. Comparison of bat activity among site-types (all species; A) and among species (all site-types; B) in the boreal forest of northeastern Ontario, Canada. Activity is represented by mean number of passes/hour (± SE). Different lowercase letters above bars denote significant differences, as determined by nonparametric multiple comparisons (P < 0.05). 2013 S.C. Mills, A.M. Adams, and R.D. Phoenix 317 but were significantly higher than the other 3 species (H5 = 46.88, P < 0.001; Fig. 3). At patch-edge sites, Hoary Bats had significantly higher activity levels than Eastern Red Bats, Northern Long-eared Bats, and Silver-haired Bats (H5 = 32.36, P < 0.001; Fig. 3). Discussion Using acoustic sampling, we demonstrated the occurrence of six species of bats in a study area presumably representative of the boreal forest of northeastern Ontario, a region where few records previously existed. Our findings support our hypothesis that all previously documented species were present, and we added to the region’s list of species by detecting the Big Brown Bat; however, Tricolored Bats were not detected in our study. Our acoustic sampling has helped fill a gap in existing data sets, similar to surveys in other regions (e.g., Virginia; Timpone et al. 2011), and has increased our knowledge of bat communities in the boreal forest of Ontario. Bat activity is commonly highest at edge habitats (e.g., Grindal and Brigham 1998, Morris et al. 2010), for reasons such as increased insect activity (Grindal and Brigham 1998, Morris et al. 2010) and corridor-like features for commuting (Owen et al. 2004). This pattern is consistent with our findings that patch edges had the highest levels of activity, most likely because of the benefit of edges to bats. Additionally, patches have greater edge-to-area ratios Figure 3. Activity, by site type (clearcut, forest edge, patch edge), of 6 species of bats in the boreal forest of northeastern Ontario, Canada. Activity is represented by mean number of passes/hour (± SE) for each species. Different lowercase letters denote species that were significantly different from each other within each site-type, as determined by nonparametric multiple comparisons (P < 0.05). 318 Northeastern Naturalist Vol. 20, No. 2 due to their relatively small size (0.25–2.0 ha) than comparable intact forest and more edge available to foraging bats. Although we focused on sampling at edges and not in the more cluttered environment within forests, we believe this approach had little impact on our detection of the highly maneuverable forest specialist, the Northern Long-eared Bat (Hogberg 2002, Kalcounis et al. 1999, Patriquin and Barclay 2003, Owen et al. 2004). Jantzen (2012) found that Northern Long-eared Bats had highest activity along edges compared to forest interiors and fields, while Sleep and Brigham (2003) reported that clutter-tolerant species still avoid cluttered areas. We predicted that Hoary Bats would be present, based on historical records, but did not expect them to be the most active species along patch edges. Hoary Bats are considered open-area specialists, because of their morphology and echolocation call characteristics (Owen et al. 2004, Veilleux et al. 2009), but were most likely attracted to the patch-edge habitat because of the intermediate level of disturbance. This intermediate level of disturbance may provide increased foraging opportunities associated with structural diversity created by irregular patch boundaries and windthrow, where trees are more susceptible to blowing down along edges. Hoary Bats also have a close association with forest habitat because they roost solitarily in foliage (Cryan and Veilleux 2007, Klug et al. 2012). Although acoustic recordings indicated that Hoary Bats were the most active species in all site-types, we consider that a difference in echolocation call characteristics and foraging strategies may explain the disagreement with our prediction that this species would be most active in clearcut areas. Hoary Bats can be more detectable because they have narrowband, low-frequency echolocation calls that travel farther and are less affected by atmospheric attenuation than the calls of the other species in the area. Like Hoary Bats, Eastern Red Bats and Silver-haired Bats are long-distance migratory species known to occur in close association with forests and roost almost exclusively in trees (Brigham 2007). Their range is fairly extensive in Ontario, as well as most of Canada from British Columbia to Nova Scotia (Kunz 1982, Shump and Shump 1982, van Zyll de Jong 1985). Eastern Red Bats roost alone in hardwood trees and prefer trees located in low-density stands (Carter and Menzel 2007, Hutchinson and Lacki 2000), which might also explain their higher activity along patch edges. Silver-haired Bats roost alone or in small groups in crevices of tree trunks, behind loose bark or the folds of heavily furrowed bark (Barclay et al. 1988, Mattson et al. 1996, Vonhof and Barclay 1996). Selectively harvested Pinus strobus L. (Eastern White Pine) stands did not exist in our study area, but are important habitat for Eastern Red Bats (Jung et al. 1999) and Silver-haired Bats elsewhere in Ontario, as both species roost preferentially in large trees (Crampton and Barclay 1998, Jung et al. 1999). These two species had relatively low activity at our site, potentially because of a lack of suitable roosting habitat. Other possibilities exist to explain the low relative activity of Eastern Red Bats, such as potential long-term population decline (see Winhold et al. 2008) or spatial partitioning with Hoary Bats (Kunz 1973). 2013 S.C. Mills, A.M. Adams, and R.D. Phoenix 319 Little Brown Bats occurred at 87.5% of sites during our study, which agrees with the extensive range and ubiquitous nature of this species throughout the rest of the province. Although they did not occur at significantly more sites than most other species, Little Brown Bats were more active than all other species, except Hoary Bats. We did not detect a difference in Little Brown Bat activity among site-types, likely because of their preference to forage (Patriquin and Barclay 2003) and commute (Hogberg et al. 2002) along edges. Their higher-than-expected level of activity in clearcut areas may be due to their avoidance of clutter (Sleep and Brigham 2003), although Kalcounis and Brigham (1995) found some intraspecific variation in Little Brown Bats, so that individuals with lower wing loading were able to forage in more cluttered environments. The Little Brown Bat typically forages above water (Jung et al. 1999) and in riparian habitats more than in upland habitats (Owen et al. 2004), although they will forage over ephemeral pools (Francl 2008). These bats may be more common in other parts of the boreal forest where standing or flowing water is more abundant. Activity levels of Northern Long-eared Bats were statistically equal in both types of edge sites, as predicted, but activity at edges was not significantly higher than at clearcut sites. We speculate that the relatively low level of activity for this species overall made it difficult to detect any difference in activity among site-types. Northern Long-eared Bats are common at latitudes above 50°N (Caceres and Barclay 2000) and are considered forest specialists, typically foraging in cluttered habitats and roosting in tree cavities or behind exfoliating bark (Henderson and Broders 2008, Henderson et al. 2008, Hogberg et al. 2002, Jung et al. 1999). Although the species can be common, it still had a lower activity level than the Hoary Bat and Little Brown Bat. Northern Long-eared Bats, though, have low-intensity, high-frequency calls that are difficult to detect (Grindal et al. 2011, Jung et al. 1999), and these bats are often under-represented in acoustic surveys. Furthermore, Grindal et al. (2011) found that Northern Long-eared Bats were more commonly captured in mistnets than detected with acoustic sampling, supporting this assertion and also confirming that different sampling techniques (e.g., capture versus acoustic) will often result in different estimates of occurrence. With no previous records of Big Brown Bats in this part of northeastern Ontario, we are now able to confirm their presence beyond the current distributional range of this species (Fig. 1). Big Brown Bats occurred at fewer sampling sites and at significantly lower levels of activity than Hoary Bats or Little Brown Bats. Although we predicted Big Brown Bats would be present in our study area, we also presume that our study site is at, or near, the northern extent of their range in northeastern Ontario. We expect the relative activity of this species to be low in the boreal forest, which may account for the low activity levels detected in our study. Kurta et al. (1989) found that this species decreased greatly in abundance between the Deciduous and Coniferous Forest Biomes, and other studies have failed to detect Big Brown Bats at the northern extent of the known range 320 Northeastern Naturalist Vol. 20, No. 2 in Ontario and Alberta (Jung et al. 1999, Patriquin and Barclay 2003). We assert that low abundance may have been a factor affecting the detection of this species. Relative activity of Big Brown Bats was equal among site types, consistent with their lack of preference for a particular type of foraging habitat (Kurta and Baker 1990). Big Brown Bats roost in buildings, rock crevices, and tree cavities (Agosta 2002, Kurta and Baker 1990) and have shown a preference for roosting sites in Quaking Aspen in southern Saskatchewan (Kalcounis and Brigham 1998). All cavities that were searched in that study showed evidence of use by bats, and Kalcounis and Brigham (1998) hypothesize that roost sites may be limiting for Big Brown Bats. Quaking Aspens are present in our study area but are not the most abundant tree species (Forestry Research Partnership 2008). Big Brown Bats normally roost within 2 km of foraging areas (Kurta and Baker 1990), and a limited number of roost sites within commuting distance of our study area may explain the low relative activity of Big Brown Bats. We were unable to confirm the presence of Tricolored Bats, even though recent evidence suggests they occur at more northern latitudes (Fraser et al. 2012). Although our site might be beyond the range of this species, there is a chance that we would not have detected Tricolored Bats in the area because they have a preference for foraging over water (Broders et al. 2001). Similarly, we may not have detected these bats near roost sites due to a lack of suitable roost trees. Although Tricolored Bats roost in many species of deciduous trees (Carter and Menzel 2007), Veilleux et al. (2003) found that roosts were located in oak trees more frequently than would be expected based on the occurrence of oaks in their study area. Also, there is no evidence that these bats roost in Paper Birch or Quaking Aspen (Carter and Menzel 2007), the most common deciduous trees in our study area. Confirming species richness of bats in northeastern Ontario is an important contribution to the efforts to conserve biodiversity in the province. With greater knowledge of which species are present in a given area, managers are better able to consider things like habitat requirements relative to proposed developments or resource-extraction activities and potential impacts of those activities and developments on habitat use or activity levels of these species. Additionally, this report and other studies (e.g., Timpone et al. 2011) provide important baseline data to inform future surveys or analyses intending to examine the impact of WNS on bat activity. Although the relatively high activity levels of Little Brown Bats in our study indicate that there still are healthy colonies in Ontario, presumably unaffected by WNS, our data provide a valuable comparison for future studies and the increased monitoring efforts for this species as WNS continues to spread. Acknowledgments The Ontario Ministry of Natural Resources’ Science and Information Branch provided funding for this project. This project was conducted at a collaborative research site established by partners from Natural Resources Canada: Canadian Forest Service, the Forestry Research Partnership, and the Ontario Ministry of Natural Resources. We thank 2013 S.C. Mills, A.M. Adams, and R.D. Phoenix 321 L. Venier for helping determine sampling locations, D. Etheridge for logistical support, and A. Chodenski, K. Cowcill, J. Dane, L. Eckert, T. Fleury, C. McLister, D. Potvin, and N. Romanow for field and analytical support. We would also like to thank L. 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