nena masthead
NENA Home Staff & Editors For Readers For Authors

Distribution and Roost Selection of Bats on Newfoundland
Allysia C. Park and Hugh G. Broders

Northeastern Naturalist, Volume 19, Issue 2 (2012): 165–176

Full-text pdf (Accessible only to subscribers.To subscribe click here.)

 

Access Journal Content

Open access browsing of table of contents and abstract pages. Full text pdfs available for download for subscribers.



Current Issue: Vol. 30 (3)
NENA 30(3)

Check out NENA's latest Monograph:

Monograph 22
NENA monograph 22

All Regular Issues

Monographs

Special Issues

 

submit

 

subscribe

 

JSTOR logoClarivate logoWeb of science logoBioOne logo EbscoHOST logoProQuest logo

2012 NORTHEASTERN NATURALIST 19(2):165–176 Distribution and Roost Selection of Bats on Newfoundland Allysia C. Park! and Hugh G. Broders2,* Abstract - We studied the distribution and ecology of male and female Myotis lucifugus (Little Brown Bats) and M. septentrionalis (Northern Long-eared Bats) on Newfoundland, where conditions (e.g., resource availability, abiotic conditions) were expected to be less favorable than in areas where most studies of conspecifics have occurred. We found that both species were patchily distributed and that Northern Long-eared Bats were more widely distributed across the island than previously documented. We located and characterized 36 roost trees from 14 female (6 lactating and 8 non-lactating) Northern Long-eared bats and found that, relative to conspecific populations on mainland North America, female Northern Long-eared Bats on the northern peninsula of Newfoundland roosted in shorter trees with smaller diameters. We also found that roosts used by lactating Northern Long-eared females were in cavities of large-diameter trees that maintained more stable microclimates compared to roosts used by non-lactating females. Introduction Characterizing population dynamics in relation to resource availability and abiotic conditions permits inference on factors that may be important for understanding evolutionary patterns and processes (Bahn et al. 2006, Holt and Keitt 2005). Peripheral populations may contain unique, heritable traits that permit persistence under conditions that conspecific populations in the core of a species’ distribution would find challenging (Kurta et al. 1996). If such populations remain isolated, speciation may occur (Lesica and Allendorf 1995). In Newfoundland, Canada, only 2 species of bats are believed to be abundant: Myotis lucifugus LeConte (Little Brown Bat) and M. septentrionalis Trouessart (Northern Long-eared Bat). Little Brown Bats are known to exist across Newfoundland (van Zyll de Jong 1985), whereas Northern Long-eared Bat records are thought to be restricted to the southwest portion of the island (Caceres and Barclay 2000), although systematic research has not been conducted beyond this area. The only previous study of bats on Newfoundland recorded few individuals and noted that foraging occurred at low ambient temperatures (<10 °C) relative to areas located more centrally within the distribution of these bats (Grindal 1999). The biotic and abiotic conditions on Newfoundland appear less favorable than those of other areas where these species have been studied previously. For example, approximately 83% of the forest in Newfoundland is dominated by just 2 species, Abies balsamea (L.) Mill. (Balsam Fir; Singh 1977) and Picea mariana Mill. (Black Spruce; DNR 2008), and this low diversity likely is due to the island’s !Department of Biology, Saint Mary’s University, Halifax, NS, B3H 3C3. 2Department of Biology, Saint Mary’s University, Halifax, NS, B3H 3C3. *Corresponding author - hugh. broders@smu.ca. 166 Northeastern Naturalist Vol. 19, No. 2 cool and moist climate (Roberts 1983). Neither species of tree is typically used for roosting by bats in other areas. In addition to its forest composition, Newfoundland has low average summer temperatures (13 °C), is adjacent to the foggiest waters in the world (Rogerson 1983), and has very strong winds. Average wind speed on the island is 22 km/hr, but mean velocities up to 34 km/hr occur in some coastal areas (Khan and Iqbal 2004). Therefore, a study of the resource use and distribution of bats on Newfoundland potentially can provide insight into the factors that limit the distribution of these species. Little Brown and Northern Long-eared Bats are sympatric throughout much of their distribution, ranging from as far south as Florida to as far north as the Yukon (Caceres and Barclay 2000, Fenton and Barclay 1980). However, the species differ in their foraging and roosting behaviors. Little Brown Bats may forage in a range of site types (LaVal et al. 1977), whereas Northern Long-eared Bats appear to be forest specialists (Broders et al. 2003, Henderson and Broders 2008). Northern Long-eared Bats roost almost exclusively in trees (Broders and Forbes 2004, Caceres and Barclay 2000, Jung et al. 2004), whereas Little Brown Bats typically roost in buildings (Fenton and Barclay 1980), though there are records of roosts in natural structures (Barclay and Cash 1985, Fenton and Barclay 1980, Kalcounis and Hecker 1996). Both species are sexually segregated during summer, with males and non-reproductive females typically remaining solitary and rarely roosting with the maternity colony (Broders and Forbes 2004, Jung et al. 2004, Kunz and Lumsden 2003, Thomas 1988). For the forest-dependent Northern Long-eared Bat, certain characteristics of forest landscapes, stands, and roost trees presumably are essential for survival, especially for reproductive females, which have the greatest energetic demands (Barclay 1989, Racey and Entwistle 2003). However, few studies characterize roosting patterns relative to reproductive stage of females. Stable, warm microclimates within cavities of roost trees promote normothermic body temperatures (Foster and Kurta 1999), offspring development during gestation, and milk production during lactation (Hamilton and Barclay 1994, Jung et al. 2004, Kerth et al. 2001b, Wilde et al. 1999). The warmest roosts tend to be located close to the canopy in the tallest and largest-diameter trees (Crampton and Barclay 1998, Kunz and Lumsden 2003). These roosts receive more solar radiation, have greater insulative properties, and house more individuals than roosts in shorter and smaller trees (Foster and Kurta 1999, Garroway and Broders 2008). Because of variation in energetic requirements during different reproductive stages (specifi cally non-lactating versus lactating), roost-site characteristics selected by females should vary to maximize energetic efficiency and increase fitness (Garroway and Broders 2008). The goal of this study was to gain a preliminary insight into the biology of bats in an area where environmental conditions and resource availability appear to be less favorable relative to sites where conspecific populations have been studied previously. Specifically, our first objective was to determine the extent of the summer distribution of Little Brown and Northern Long-eared Bats on 2012 A.C. Park and H.G. Broders 167 Newfoundland. Our second objective was to characterize roost-site selection of female lactating and non-lactating Northern Long-eared Bats and compare roosttree selection and roost-temperature profiles between the groups. Methods Field-site description Newfoundland lies within the wet boreal forest region, which supports dominant conifer stands (Thompson et al. 2003). These stands consist primarily of Balsam Fir and Black Spruce (Campbell and Laroque 2007), which thrive on moisture accumulated from high amounts of precipitation and fog (Thompson et al. 2003). Betula papyrifera Marsh. (White Birch) is the only major hardwood species in this region (Roberts et al. 1998). However, Picea glauca (Moench) Voss (White Spruce), Populus tremuloides Michx. (Trembling Aspen), Prunus pensylvanica L.f. (Pin Cherry), and Sorbus americana Marsh. (American Mountain Ash) are also present (Thompson et al. 2003). Distribution of bats on Newfoundland From 3 June to 4 August 2008, we conducted surveys using harp traps (Austbat Research Equipment, Lower Plenty, Victoria, Australia) along forested trails at 14 areas on Newfoundland (Fig. 1). Forested trails are used by bats for commuting (Downs and Racey 2006) and are an ideal site for trapping (Henderson et al. 2008). Research on Prince Edward Island, Canada, found rivers to be a key predictor of the presence of Northern Long-eared Bats (Henderson et al. 2008), so only areas that contained at least 1 river were included in our study. Harp traps were deployed before sunset and checked every 0.5 h for 3 h. At each of the 14 areas, we trapped bats at 1–5 locations along trails, for a total of 35 sampled locations. All captured bats were identified to species, weighed, aged (Anthony 1988), sexed, and had their reproductive condition assessed. Bats were identified as pregnant by palpating the abdomen and as lactating via the presence of exposed skin around the nipple and/or presence of milk (Racey 1988). All bats were released at the site of capture after processing. Sampling did not occur on nights with heavy rain. Methods for capturing and handling bats followed the guidelines of the American Society for Mammalogists (Gannon and Sikes 2007) and were approved by the Saint Mary’s University Animal Care Committee, Parks Canada, and the Newfoundland and Labrador Department of Environment and Conservation. Roost selection by female Northern Long-eared Bats From 15 June to 10 August 2009, we fitted female Northern Long-eared Bats on the northern peninsula of Newfoundland, near the community of River of Ponds (50°32´N, 57°24´W), with 0.42-g radio-transmitters (model LB-2N, Holohil Systems, Carp, ON, Canada), representing, on average (± S.E.), 4.8 ± 0.15 % of the bat’s mass. All bats were located every day until the transmitter fell off or failed. 168 Northeastern Naturalist Vol. 19, No. 2 To characterize roost-site selection, a 17.8-m-radius plot (0.1-ha), centered on roost trees, was surveyed when bats were known to be not roosting in the tree. Within each plot, both live trees and snags were counted, and diameter (dbh) of the roost tree was measured. Canopy height was defined as the average height of 5 representative trees and determined using a clinometer (model PM-5/1520, Suunto, Vantaa, Finland). Roost height relative to the canopy was calculated by subtracting canopy height from roost height. Based on a review of the literature on roosting behaviors of female Northern Long-eared Bats (e.g., Carter and Feldhamer 2005, Garroway and Broders 2008), we created a set of 9 a priori logistic models, each representing alternative hypotheses to differentiate roosts used by lactating and non-lactating bats. Because only 36 roosts and their respective stand plots were analyzed, all but 1 model contained only 1 or 2 predictive variables (Hosmer and Lemeshow Figure 1. Distribution of male and female Little Brown and Northern Long-eared Bats on Newfoundland during summer 2008, as determined by systematic harp-trap surveys. 2012 A.C. Park and H.G. Broders 169 2000). The candidate models and respective variables were ranked by secondorder Akaike’s information criterion (AICC ; Burnham and Anderson 2002) using SYSTAT 12 (SYSTAT software, Inc. 2001), and the 95% confidence set was used for inference. Model-averaged parameter estimates (βi) and unconditional standard errors (S.E.) were calculated (Burnham and Anderson 2002), and only those variables for which the parameter estimate ± S.E. did not overlap zero were used for inference. To characterize the temperature profile of roosts, ambient temperature (± 1 °C) was measured every hour within the study areas using data loggers (iButton, Dallas Semiconductor Corporation, Dallas, TX). Loggers were placed directly on tree trunks, shaded under canopy cover to eliminate direct exposure to solar radiation, at 1.5 m above ground level. Data loggers were also placed in different roosts (once bats were known not to be using the roost) for 6–18 days to facilitate comparison of roost temperature to ambient temperature. A generalized linear model was used to determine whether variation in roost temperature profile, relative to ambient, varied between trees used by lactating and non-lactating bats (Crawley 2007). Results Distribution of bats on Newfoundland In 2008, 22 Little Brown (7 male:15 female) and 29 Northern Long-eared Bats (10:19) were captured. Little Brown Bats were caught in only 5 of the 14 areas, and Northern Long-eared Bats were captured at 9 of 14 areas (Fig. 1). No pregnant Little Brown Bats were caught; however, the first occurrence of a lactating Little Brown Bat was on 18 July, and the first record of a volant young-of-theyear was on 28 July. The only records for pregnant Northern Long-eared Bats occurred on 22 June and 4 July. The first lactating Northern Long-eared Bat was trapped on 7 July, and all females of this species caught after that date showed signs of lactation. No juvenile Northern Long-eared Bats were caught. Roost selection by female Northern Long-eared Bats In 2009, 18 female Northern Long-eared Bats (8 lactating and 10 non-lactating) were caught, 14 of which (6 lactating and 8 non-lactating) were tracked for 1 to 11 days to 36 roost trees (Table 1), for 60 bat-days, with a bat-day defined as 1 radiotracked bat roosting in 1 tree for 1 day. During the lactation period (10–31 July Table 1. Sample size and mean characteristics (S.E.) of roosts used by lactating and non-lactating Northern Long-eared Bats near River of Ponds, Newfoundland, in 2009. Roost-site characteristics Lactating Non-lactating n bats 6 8 n roost trees 13 23 Roost-tree diameter (cm) 31.7 (2.2) 22.7 (2.0) Canopy height relative to roost height (m) 12.8 (1.9) 11.3 (1.3) Total number of live trees (number/ha) 144.5 (19.5) 96.1 (9.4) Total number of snags (number/ha) 13.9 (1.7) 14.1 (1.4) 170 Northeastern Naturalist Vol. 19, No. 2 2009), 2 of the 8 females tracked were non-lactating. Nine roost trees were used on >1 day by either the same or different individuals, with 1 roost occupied for 11 batdays by 4 bats; 3 roost trees were used by more than 1 tracked bat. Bats roosted an average of 1136 m (range: 71–2375 m) from the capture site. At least 3 species of trees were used as roosts. Thirteen roosts were in Balsam Fir, 1 was in Black Spruce, and 10 were in White Birch. The remaining 12 trees Table 2. Ranked Akaike weights (wi) and sum of Akaike weights (Σwi) for all a priori selected candidate models for differentiating characteristics of sites and roosts used by lactating and non-lactating Northern Long-eared Bats. The first four models formed the 95% confidence set. Model wi Σwi Canopy relative to roost, roost-tree diameter 0.534 0.534 Canopy relative to roost, roost tree-diameter, total number of live trees 0.247 0.781 Canopy relative to roost, total number of live trees 0.107 0.888 Canopy relative to roost 0.071 0.959 Roost tree diameter 0.022 0.981 Roost tree diameter, total number of snags 0.013 0.994 Total number of live trees 0.005 0.998 Total number of live trees, total number of snags 0.001 1.000 Total number of snags 0.000 1.000 Figure 2. Temperature inside roosts occupied by lactating and non-lactating Northern Long-eared Bats versus ambient temperature, near River of Ponds, Newfoundland. 2012 A.C. Park and H.G. Broders 171 were not identified due to advanced decay. Roosts used by lactating and nonlactating bats were predominately snags (87 and 92%, respectively). Exit counts were performed on 39 occasions. Mean group size was 9.0 (range: 1–19, n = 12) for lactating bats and 7.6 (range: 1–28, n = 27) for non-lactating females. The 95% confidence set of models to differentiate roosts used by lactating and non-lactating Northern Long-eared Bats consisted of 4 models (Table 2). At the local level, for every 2.0-cm increase in diameter of a roost tree (βDBH = 0.105 ± 0.051), the odds that it was a tree used by a lactating Northern Longeared Bat increased by 1.23 (95% CI: 1.01–1.51). At the stand level, for every increase of 5 trees (βTREES = 0.007 ± 0.008) within a 0.1-ha plot, the odds that it was used by a lactating Northern Long-eared Bat increased by 1.05 times (95% CI: 0.97–1.14). Roost microclimate On average, lactating Northern Long-eared females used roost trees that were significantly larger (dbh = 31.7 ± 2.2 cm, n = 12) than the roost trees used by nonlactating females (dbh = 22.7 ± 2.0 cm, n = 23; ANOVA, F1, 33 = 9.0, P = 0.005). Microclimate temperature patterns, relative to ambient, also differed between roost-sites used by lactating and non-lactating bats (Fig. 2). Variation in the slope of the regression lines of ambient vs. roost temperature for trees used by lactating vs. non-lactating bats was significantly different from one another (P < 0.001). On average, the slope was 0.60 ± 0.04 (n = 2, r2 = 0.68–0.88) for roosts used by lactating bats (n = 2, r2 = 0.68 and 0.88) and 1.35 ± 0.05 (n = 4, r2 = 0.62–0.86) for roosts used by non-lactating bats, suggesting that lactating bats selected cavity roots in large trees that had lower temperature fluctuations than roosts used by non-lactating bats. Discussion Consistent with other studies of bats in eastern Canada (Farrow and Broders 2010, Henderson et al. 2008), both Little Brown and Northern Long-eared Bats were patchily distributed on the island of Newfoundland. Surprisingly, despite the more generalist nature of Little Brown Bats, they were caught at fewer locations than Northern Long-eared Bats, and the only location where only Little Brown Bats were caught was on the Avalon Peninsula at Salmonier. Northern Long-eared Bats were found farther east and north than previously reported (Caceres and Barclay 2000). Throughout the core of their geographic distribution, female Northern Longeared Bats roost in a variety of tree species that typically are larger than those found on Newfoundland (e.g., Broders and Forbes 2004, Foster and Kurta 1999, Sasse and Pekins 1996). On Newfoundland, softwood species (particularly Balsam Fir) were most commonly used as roost trees (58% of identified roosts). Balsam Fir is a short-lived species, and “old growth” conditions for this conifer typically last only 20–30 years (Thompson et al. 2003). On Newfoundland, the amount of old-growth forest has declined considerably since the 1940s because of logging, and infestations of both Lambdina fiscellaria Guenee (Hemlock 172 Northeastern Naturalist Vol. 19, No. 2 Looper) and Choristoneura fumiferana Clemens (Spruce Budworm) (Thompson et al. 2003). Therefore, relative to roosts available to females in central areas of the distribution of Northern Long-eared Bats in North America, only smaller and shorter roost trees are widely available in Newfoundland and are selected by the bats. Energetic requirements of bats not only differ by gender, but also by reproductive status. Non-reproductive females, like males, have less energetic cost associated with reproduction and should therefore have greater flexibility in roost-site selection (Barclay 1991, Mills et al. 1996, Thomas 1988). Gestation, however, may result in bats selecting warmer roosts to reduce the amount of energy required to sustain normothermic body temperature and facilitate fetal growth (Kerth et al. 2001a, Kunz and Lumsden 2003, McLean and Speakman 1999, Wilkinson 1992). During lactation, the most energy-intense period for both mother and offspring (Kurta et al. 1989, Racey and Swift 1981), females allocate most energy reserves not spent on foraging to milk production (Wilde et al. 1999). In our study, roost-tree characteristics selected by lactating Northern Long-eared Bats appeared to coincide with energetic demands, relative to those of bats that were non-lactating. Lactating bats roosted in trees that were larger in diameter, presumably to decrease energy expenditure. The relationship between roost-tree diameter and reproductive status is supported by prior studies that compared characteristics of roost trees used by female Northern Long-eared Bats to those of randomly selected trees (Sasse and Perkins 1996) or trees occupied by males (Perry and Thill 2007), and characteristics of trees used by maternity colonies to those used by solitary females (Lacki and Schwierjohann 2001). Garroway and Broders (2008) found that, during lactation, roosts of Northern Long-eared Bats were exposed to increased solar radiation and had less surrounding clutter (i.e., roosts were situated high in tall trees that were surrounded by an open canopy and a low number of trees in the stand). These roosts were expected to be warmer due to greater exposure to sunlight (Betts 1998, Vonhof and Barclay 1996), which is especially important when the growing season for young is short (Kerth et al. 2001b, Lewis 1993). Insulation and temperature of roost cavities is also largely dictated by the size of the tree in which it is located. Large-diameter trees provide more insulation and are less affected by ambient conditions, enabling them to maintain more stable microclimates than trees with smaller diameters (Coombs et al. 2010, Nicolai 1986, Vonhof and Barclay 1997). Roost microclimate has not been widely studied in the past due to difficulty of access. For studies that have been successful, reproductive bats seem to select roosts with more stable microclimates relative to roosts used by non-reproductive females (Burnett and August 1981, Kalcounis and Hecker 1996, Sedgeley 2001). This study examined the distribution of bats on Newfoundland and provided insight into roost selection at the periphery of a species’ range. We have revealed factors that likely influence roosting- and foraging-site selection for forestdependent Northern Long-eared Bats and show that roost-site selection differs here from that in the interior of their North American distribution. However, even 2012 A.C. Park and H.G. Broders 173 at the northeastern extreme, which contains forest features that are less likely to be chosen by Northern Long-eared females at the core of their distribution, the overall trend of roost-site selection is similar. Females that were lactating and undergoing conditions that required significant energy resources selected roost cavities in large diameter trees that provided warmer, more stable microclimates than those used by bats that were non-lactating. This finding supports the contention that lactating females are more sensitive to distribution-limiting factors than non-lactating females. Acknowledgments We are grateful to all private park-owners and landowners in the community of River of Ponds, who granted access to their land. Logistic support was provided by Newfoundland and Labrador’s Parks and Natural Areas Division, Parks Canada, and the Newfoundland and Labrador’s Forest Resources and Agrifoods Division in the Department of Natural Resources. Funding was provided by the Wildlife Division of the Newfoundland and Labrador Department of Environment and Conservation, the Animal Health Division of the Newfoundland and Labrador Department of Natural Resources, and Saint Mary’s University. Field assistants included G. Bateman, L. Burns, S. Caines, S. Chessel, K. Letto, M. Makowska, and A. Wells. Literature Cited Anthony, E.L.P. 1988. Age determination in bats. Pp. 47–58, In T.H. Kunz (Ed.). Ecological and Behavioral Methods for the Study of Bats. Smithsonian Institution Press, Washington, DC. 533 pp. Bahn, V., R.J.J. O'Connor, and W.B. Krohn. 2006. Effect of dispersal at range edges on the structure of species ranges. Oikos 115:89–96. Barclay, R.M.R. 1989. The effect of reproductive condition on the foraging behavior of female Hoary Bats, Lasiurus cinereus. Behavioral Ecology and Sociobiology 24:31–37. Barclay, R.M.R. 1991. Population structure of temperate zone insectivorous bats in relation to foraging behaviour and energy demand. Journal of Animal Ecology 60:165–178. Barclay, R.M.R., and K.J. Cash. 1985. A non-commensal maternity roost of the Little Brown Bat (Myotis lucifugus). Journal of Mammalogy 66:782–783. Betts, B.J. 1998. Roosts used by maternity colonies of Silver-haired Bats in northeastern Oregon. Journal of Mammalogy 79:643–650. Broders, H.G., and G.J. Forbes. 2004. Interspecific and intersexual variation in roostsite selection of Northern Long-eared and Little Brown Bats in the Greater Fundy National Park ecosystem. Journal of Wildlife Management 68:602–610. Broders, H.G., G.M. Quinn, and G.J. Forbes. 2003. Species status, and the spatial and temporal patterns of activity of bats in southwest Nova Scotia, Canada. Northeastern Naturalist 10:383–398. Burnett, C.D., and P.V. August. 1981. Time and energy budgets for dayroosting in a maternity colony of Myotis lucifugus. Journal of Mammalogy 62:758–766. Burnham, K.P., and D.R. Anderson. 2002. Model Selection and Multimodel Inference: A Practical Information-Theoretic Approach. Springer-Verlag, New York, NY. 514 pp. Caceres, C., and R.M.R. Barclay. 2000. Myotis septentrionalis. Mammalian Species 634:1–4. 174 Northeastern Naturalist Vol. 19, No. 2 Campbell, L.J., and C.P. Laroque. 2007. Decay progression and classification in two oldgrowth forests in Atlantic Canada. Forest Ecology and Management 238:293–301. Carter, T.C., and G.A. Feldhamer. 2005. Roost tree use by maternity colonies of Indiana Bats and Northern Long-eared Bats in southern Illinois. Forest Ecology and Management 219:259–268. Coombs, A.B., J. Bowman, and C.J. Garroway. 2010. Thermal properties of tree cavities during winter in a northern hardwood forest. Journal of Wildlife Management 74:1875–1881. Crampton, L.H., and R.M.R. Barclay. 1998. Selection of roosting and foraging habitat by bats in different-aged aspen mixed wood stands. Conservation Biology 12:1347–1358. Crawley, M.J. 2007. The R Book. John Wiley and Sons, Ltd., West Sussex, UK. 942 pp. Department of Natural Resources, Government of Newfoundland and Labrador (DNR). 2008. Forest types. Available online at http://www.nr.gov.nl.ca/forestry/. Accessed February 2008. Downs, N.C., and P.A. Racey. 2006. The use by bats of habitat features in mixed farmland in Scotland. Acta Chiropterologica 8:169–185. Farrow, L.J., and H.G. Broders. 2010. Loss of forest cover impacts the distribution of the forest-dwelling Tri-colored Bat (Perimyotis subflavus). Mammalian Biology 76:172–179. Fenton, M.B., and R.M.R. Barclay. 1980. Myotis lucifugus. Mammalian Species 142:1–8. Foster, R.W., and A. Kurta. 1999. Roosting ecology of the Northern Bat (Myotis septentrionalis) and comparisons with the endangered Indiana Bat (Myotis sodalis). Journal of Mammalogy 80:659–672. Gannon, W.L., and R.S. Sikes. 2007. Guidelines of the American Society of Mammalogists for the use of wild mammals in research. Journal of Mammalogy 88:809–823. Garroway, C.J., and H.G. Broders. 2008. Day-roost characteristics of Northern Longeared Bats (Myotis septentrionalis) in relation to female reproductive status. Ecoscience 15:89–93. Grindal, S.D. 1999. Habitat use by bats, Myotis spp., in western Newfoundland. Canadian Field-Naturalist 113:258–263. Hamilton, I.M., and R.M.R. Barclay. 1994. Patterns of daily torpor and day-roost selection by male and female Big Brown Bats (Eptesicus fuscus). Canadian Journal of Zoology 72:744–749. Henderson, L.E., and H.G. Broders. 2008. Movements and resource selection of the Northern Long-eared Myotis (Myotis septentrionalis) in a forest-agriculture landscape. Journal of Mammalogy 89:952–963. Henderson, L.E., L.J. Farrow, and H.G. Broders. 2008. Intra-specific effects of forest loss on the distribution of the forest-dependent Northern Long-eared Bat (Myotis septentrionalis). Biological Conservation 141:1819–1828. Holt, R.D., and T.H. Keitt. 2005. Species’ borders: A unifying theme in ecology. Oikos 108:3–6. Hosmer, D.W., and S. Lemeshow. 2000. Applied Logistic Regression. John Wiley and Sons, Inc., Toronto, ON, Canada. 392 pp. Jung, T.S., I.D. Thompson, and R.D. Titman. 2004. Roost site selection by forestdwelling male Myotis in central Ontario, Canada. Forest Ecology and Management 202:325–335. 2012 A.C. Park and H.G. Broders 175 Kalcounis, M.C., and K.R. Hecker. 1996. Intraspecific variation in roost-site selection by Little Brown Bats (Myotis lucifugus). Pp. 81–90, In R.M.R. Barclay and R.M. Brigham (Eds.). Bats and Forest Symposium. British Columbia Ministry of Forests, Victoria, BC, Canada. 292 pp. Kerth, G., M. Wagner, and B. König. 2001a. Roosting together, foraging apart: Information transfer about food is unlikely to explain sociality in female Bechstein's Bats (Myotis bechsteinii). Behavioral Ecology and Sociobiology 50:283–291. Kerth, G., K. Weissmann, and B. König. 2001b. Day-roost selection in female Bechstein's Bats (Myotis bechsteinii): A field experiment to determine the influence of roost temperature. Oecologia 126:1–9. Khan, M.J., and M.T. Iqbal. 2004. Wind energy resource map of Newfoundland. Renewable Energy 29:1211–1221. Kunz, T.H., and L.F. Lumsden. 2003. Ecology of cavity and foliage roosting bats. Pp. 3–90, In T.H. Kunz and M.B. Fenton (Eds.). Bat Ecology. University of Chicago Press, Chicago, IL. 779 pp. Kurta, A., G.P. Bell, K.A. Nagy, and T.H. Kunz. 1989. Energetics of pregnancy and lactation in free-ranging Little Brown Bats (Myotis lucifugus). Physiological Zoology 62:804–818. Kurta, A., K.J. Williams, and R. Mies. 1996. Ecological, behavioural, and thermal observations of a peripheral population of Indiana Bats (Myotis sodalis). Pp. 102–117, In R.M.R. Barclay and R.M. Brigham (Eds.). Bats and Forest Symposium. British Columbia Ministry of Forests, Victoria, BC, Canada. 292 pp. Lacki, M.J., and J.H. Schwierjohann. 2001. Day-roost characteristics of Northern Bats in mixed mesophytic forest. Journal of Wildlife Management 65:482–488. LaVal, R.K., R.L. Clawson, M.L. LaVal, and W. Caire. 1977. Foraging behavior and nocturnal activity patterns of Missouri bats, with emphasis on the endangered species Myotis grisescens and Myotis sodalis. Journal of Mammalogy 58:592–599. Lesica, P., and F.W. Allendorf. 1995. When are peripheral populations valuable for conservation? Conservation Biology 9:753–760. Lewis, S.E. 1993. Effect of climatic variation on reproduction by Pallid Bats (Antrozous pallidus). Canadian Journal of Zoology 71:1429–1433. McLean, J.A., and J.R. Speakman. 1999. Energy budgets of lactating and non-reproductive Brown Long-eared Bats (Plecotus auritus) suggest females use compensation in lactation. Functional Ecology 13:360–372. Mills, D.J., T.W. Norton, H.E. Parnaby, R.B. Cunningham, and H.A. Nix. 1996. Designing surveys for microchiropteran bats in complex forest landscapes: A pilot study from southeast Australia. Forest Ecology and Management 85:149–161. Nicolai, V. 1986. The bark of trees: Thermal properties, microclimate, and fauna. Oecologia 69:148–160. Perry, R.W., and R.E. Thill. 2007. Roost selection by male and female Northern Long-eared Bats in a pine-dominated landscape. Forest Ecology and Management 247:220–226. Racey, P.A. 1988. Reproductive assessment in bats. Pp. 31–45, In T.H. Kunz (Ed.). Ecological and Behavioral Methods for the Study of Bats. Smithsonian Institution Press, Washington, DC. 533 pp. Racey, P.A., and A.C. Entwistle. 2003. Conservation ecology of bats. Pp. 680–744, In T.H. Kunz and M.B. Fenton (Eds.). Bat Ecology. University of Chicago Press, Chicago, IL. 779 pp. 176 Northeastern Naturalist Vol. 19, No. 2 Racey, P.A., and S.M. Swift. 1981. Variations in gestation length in a colony of Pipistrelle Bats (Pipistrellus pipistrellus) from year to year. Journal of Reproduction and Fertility 61:12–129. Roberts, B.A. 1983. Soils. Pp. 107–162, In R.G. South (Ed.). Biogeography and Ecology of the Island of Newfoundland. Dr. W. Junk Publishers, Boston, MA. 740 pp. Roberts, B.A., K.W. Deering, and B.D. Titus. 1998. Effects of intensive harvesting on forest floor properties in Betula papyrifera stands in Newfoundland. Journal of Vegetation Science 9:521–528. Rogerson, R.J. 1983. Geological evolution. Pp. 5–36, In R.G. South (Ed.). Biogeography and Ecology of the Island of Newfoundland. Dr. W. Junk Publishers, Boston, MA. 740 pp. Sasse, D.B., and P.J. Pekins. 1996. Summer roosting ecology of Northern Long-eared Bats (Myotis septentrionalis) in the White Mountain National Forest. Pp. 91–101, In R.M.R. Barclay and R.M. Brigham (Eds.). Bats and Forest Symposium. British Columbia Ministry of Forests, Victoria, BC, Canada. 292 pp. Sedgeley, J.A. 2001. Quality of cavity microclimate as a factor influencing selection of maternity roosts by a tree-dwelling bat, Chalinolobus tuberculatus, in New Zealand. Journal of Applied Ecology 38:425–438. Singh, P. 1977. Broom rusts of Balsam Fir and Black Spruce in Newfoundland. European Journal of Forest Pathology 8:25–36. Thomas, D.W. 1988. The distribution of bats in different ages of Douglas-Fir forests. Journal of Wildlife Management 52:619–626. Thompson, I.D., D.J. Larson, and W.A. Montevecchi. 2003. Characterization of old “wet boreal” forests, with an example from Balsam Fir forests of western Newfoundland. Environmental Reviews 11:23–46. van Zyll de Jong, C.G. 1985. Handbook of Canadian Mammals. 2. Bats. National Museums of Canada, Ottawa, ON, Canada. 212 pp. Vonhof, M.J., and R.M.R. Barclay. 1996. Roost-site selection and roosting ecology of forest-dwelling bats in southern British Columbia. Canadian Journal of Zoology 74:1797–1805. Vonhof, M.J., and R.M.R. Barclay. 1997. Use of tree stumps as roosts by the Western Long-eared Bat. Journal of Wildlife Management 61:674–684. Wilde, C.J., C.H. Knight, and P.A. Racey. 1999. Influence of torpor on milk protein composition and secretion in lactating bats. Journal of Experimental Zoology 284:35–41. Wilkinson, G. 1992. Communal nursing in the Evening Bat, Nycticeius humeralis. Behavioral Ecology and Sociobiology 31:225–235.