Bats of Pisgah State Park, New Hampshire Jacques Pierre Veilleux1,*, Howard H. Thomas2, and Paul R. Moosman, Jr.2 Abstract - Published data that describe the distribution and reproductive patterns of bats in New Hampshire are sparse. We examined the distribution and reproductive phenology of bats within Pisgah State Park (the largest state park in New Hampshire) located in the southwestern region of the state. A total of 159 bats was captured during 31 net nights at 29 net sites during the summers of 2004 and 2005. In order of decreasing abundance, the most common species were Myotis lucifugus (little brown myotis), Eptesicus fuscus (big brown bat), and M. septentrionalis (northern myotis). Additionally, a single Lasiurus borealis (eastern red bat) was captured. Approximately equal numbers of adult male and female little brown myotis and northern myotis were observed, while sex ratios of big brown bats were female biased. Pregnant females of each species were observed between mid-May and early June, and parturition occurred during mid- to late June. Captures of juvenile little brown myotis indicate that weaning begins during early July (juveniles of other species were not captured). Introduction Although bats comprise approximately 15% of the native terrestrial mammal taxa in New Hampshire, information about their distribution and abundance in the state is limited. Much of that information is only available in unpublished reports (e.g., Chenger 2003). Nine species of bats are known to occur in New Hampshire (Godin 1977, Whitaker and Hamilton 1998), including: Myotis leibii Audubon and Bachman (eastern small-footed myotis), M. lucifugus LeConte (little brown myotis), M. septentrionalis Trouessart (northern myotis), M. sodalis Miller and Allen (Indiana myotis), Lasiurus borealis Müller (eastern red bat), L. cinereus Beauvois (hoary bat), Lasionycteris noctivagans LeConte (silver-haired bat), Eptesicus fuscus Beauvois (big brown bat), and Perimyotis subflavus Cuvier (eastern pipistrelle). Three of these are endangered or species of concern: Indiana myotis, eastern small-footed myotis, and eastern pipistrelle (New Hampshire Natural Heritage Bureau 2004). Indiana myotis are federally endangered and their known distribution in New Hampshire is limited to a single record from Albany, Carroll County (Krusic 1995), although the validity of this record is in question. Eastern small-footed myotis are state endangered due to their rarity and vulnerability of winter hibernacula in New Hampshire. Summer records of eastern small-footed myotis are known from only five localities, including: the White Mountain National Forest (no specific locality reported; Krusic 1995), Bartlett 2008 NORTHEASTERN NATURALIST 15(1):25–34 1Department of Biology, Franklin Pierce University, Rindge, NH 03461. 2Department of Biology, Fitchburg State College, Fitchburg, MA 01420. *Corresponding author - veilleuxj@franklinpierce.edu. 26 Northeastern Naturalist Vol. 15, No. 1 (Carroll County; Chenger 2004), New Boston (Hillsborough County; LaGory et al. 2002), Peirmont (Grafton County; Chenger 2004), and Surry (Cheshire County; Chenger 2003). Likewise, eastern pipistrelles are a species of concern in New Hampshire, with only three capture records during summer. These records include one individual from Enfield (Grafton County; museum record from the Cornell University Museum of Vertebrates), and single individuals captured in the towns of Bartlett and Warren (Grafton County), respectively (Chenger 2004). The remaining species of bats are not protected in New Hampshire, but their status and distribution are mostly unknown. For example, a single silver-haired bat has been observed in the state (Bartlett; Sasse 1995); only five eastern red bats have been reported from six localities: Martin’s Location and Bean’s Purchase (Coos County; Chenger 2004), Bartlett and Piermont (Chenger 2004), New Boston (LaGory et al. 2002), and the White Mountain National Forest (Sasse 1995; no specific locality information reported); and six records of hoary bats are available from four localities: Livermore (Grafton County; Sasse and Pekins 1996; D.B. Sasse, Arkansas Game and Fish Commission, Little Rock, AR, pers. comm.), the White Mountain National Forest (no specific locality information reported; Krusic 1995), New Boston (LaGory et al. 2002), and Conway (Carroll County; museum record from the Carnegie Mellon Natural History Museum). Even species presumed to be common, such as big brown bat, little brown myotis, and northern myotis, have been reported from few locations, although most studies conducted in New Hampshire (i.e., peer reviewed and gray literature) have documented these species. The paucity of data describing the distribution and abundance of bats in New Hampshire prevents informed conservation decisions and suggests a need for extensive survey efforts. Therefore, we present results of a survey of the bat community at Pisgah State Park, the largest state park in New Hampshire. Results presented here represent an important contribution to the knowledge of the distribution, relative abundance, and life history of bats in New Hampshire. Field-site Description Pisgah State Park contains >5380 contiguous hectares and is located within three townships (Chesterfield, Hinsdale, and Winchester) in southwestern Cheshire County (42°50'N, 72°26'W). The Park is undeveloped, except for an extensive network of unpaved access roads and hiking trails located throughout the park (Fig. 1). Elevation ranges from approximately 170 to 400 m asl. The park contains several habitat types, including low- and high-elevation wetlands, limited high-elevation exposed rock outcrops, open-water bodies (including an 83-ha reservoir), small streams, and coniferous, mixed conifer/deciduous, and deciduous forests. Major conifer species include Pinus strobus L. (white pine), 2008 J.P. Veilleux, H.H. Thomas, and P.R. Moosman, Jr. 27 Tsuga canadensis (L.) Carr. (eastern hemlock), and Picea mariana (P. Mill.) B.S.P. (black spruce), while common deciduous species include Acer saccharum Marsh (sugar maple), A. rubrum L. (red maple), Fagus grandifolia Ehrh. (American beech), Quercus rubra L. (northern red oak), Figure 1. Map of Pisgah State Park indicating locations of mist net samples. The following symbols represent species (E. fuscus = EF [big brown bat]; M. lucifugus = ML [little brown myotis]; M. septentrionalis = MS [northern myotis]; L. borealis = LB [eastern red bat]) captured at each mist net site: ★ = EF, ML, MS, LB; g = EF, ML, MS; ♦ = EF, ML; l = ML, MS; s = ML; t = EF; : = MS; X = no bats were captured. 28 Northeastern Naturalist Vol. 15, No. 1 Populus spp. (aspen), Betula alleghaniensis Britt. (yellow birch), and B. lenta L. (black or sweet birch). Forests are mainly second growth, but approximately 3 small (i.e., several ha) old-growth remnants remain. Methods Bats were captured using mist nets. Each mist net site consisted of 2 mist nets, erected one above the other, for a total surface area of 45 m2 (9 m long by 5 m high). Mist nets were mainly placed across access roads and to a lesser extent across woodland streams (n = 2) that served as travel corridors for bats. Nets were attended by observers from dusk until midnight, except for 4 nights when netting ceased early due to rain. A global positioning system (GPS) receiver (model 12XL, Garmin, Olathe, KS) was used to determine latitude and longitude at each mist net location. These data were subsequently downloaded to digital USGS quadrangle maps (Terrain Navigator, Version 6.03, Amesbury, MA) and transposed to a detailed map of Pisgah (Fig. 1). Gender, age, body mass, and reproductive condition were recorded for each bat. Age class (adult or juvenile) was determined by degree of ossification of epiphyseal plates in the phalanges (Anthony 1988). Adult females were classed as pregnant by degree of distention of the abdomen, although adult females captured early in the season with non-distended abdomens were assumed to be in early stages of pregnancy (Cagle and Cockrum 1942, Humphrey and Cope 1976). Lactation was determined by whether milk could be expressed by palpating the nipples (Racey 1988). Bats were considered post-lactating if no milk could be expressed from nipples that showed signs of recent suckling (hairless teats), and non-breeding if the abdomen was not distended during the later pregnancy period. Males were classified as scrotal (testes descended within the uropatagium) or abdominal (testes within the abdomen). A numbered aluminum wing band (Porzana Ltd., East Sussex, UK) was affixed to each bat (left wing of females, right wing of males; Barclay and Bell 1988) before release at site of capture. Descriptive statistics are reported as mean ± standard error (SE). Two-tailed t-tests were conducted to test for differences in forearm lengths between adult males and females for each species. Binomial tests were used to test for differences in abundance of males and females with each species. Statistical analyses were conducted using SPSS 14.0 at α = 0.05. Results Captures A total of 31 net nights was completed at 29 sites between 14 May–11 September 2004 and 17 May–20 June 2005 (one site was sampled three times). Sampling sites were located throughout the Park (Fig. 1), although portions of the Park were inaccessible by road or trail, or did not have adequate 2008 J.P. Veilleux, H.H. Thomas, and P.R. Moosman, Jr. 29 characteristics for successful mist netting (i.e., closed forests without a travel corridor). Elevation of sampling sites ranged from 177 to 333 m. One-hundred fifty-nine bats, representing four species, were captured during the survey. In order of decreasing abundance, captures included: 104 little brown myotis, 42 big brown bats, 12 northern myotis, and 1 eastern red bat that escaped prior to processing. Capture rate per net night was 3.4 bats/net night for little brown myotis, 1.4 for big brown bats, 0.4 for northern myotis, and 0.03 for eastern red bat. Bats were captured during sampling periods on all but 2 nights. Little brown myotis were observed at 19, big brown bats at 17, and northern myotis at 11 of the 29 sampling sites. Sex Ratios and Reproductive Patterns Nearly equal numbers of adult male (n = 45) and female (n = 47) little brown myotis were captured (binomial test, P = 0.92), with 16 adult males possessing scrotal testes. Scrotal males were observed throughout spring and summer (1 in May, 2 in June, 4 in July, 6 in August, and 3 in September; Fig. 2). Captures of abdominal males were as follows: 8 in May, 16 in June, 3 in July, 0 in August, and 2 in September. Pregnant females were captured as early as 14 May (the earliest sampling date during either year) until 8 June, and lactating females were captured from 8 June until 1 July. The first Figure 2. Reproductive phenology of adult male M. lucifugus (little brown myotis; white bars) and E. fuscus (big brown bat; black bars) as indicated by the percent of adult males with scrotal testes relative to total males captured during each month of sampling (May through September). No male E. fuscus were captured during September. 30 Northeastern Naturalist Vol. 15, No. 1 post-lactating little brown myotis was captured on 6 July, and post-lactating females were observed for the remainder of the summer. A total of 5 juvenile little brown myotis was captured (all males), beginning on 1 July and continuing until 12 September (the latest sampling date). Mean ± SE mass (g) and forearm (mm) measurements for each sex, age, and adult female reproductive class are included in Table 1. Forearm length was not significantly different between adult male and female little brown myotis (t = -0.14, d.f. = 95, P = 0.889). In contrast to little brown myotis, greater numbers of adult male big brown bats were captured than females (78% male; n = 42; binomial test, P ≤ 0.001), with 1 individual escaping prior to sex or age determination. Seventeen adult male big brown bats had scrotal testes and 14 had abdominal testes. Scrotal and abdominal males were observed throughout the season, with captures of scrotal males as follows: 7 in May, 5 in June, 2 in July, and 3 in August (Fig. 2). Captures of abdominal males were as follows: 8 in May, 5 in June, and 1 in July. Earliest capture of a pregnant female occurred on 14 May (n = 1), with the remaining pregnant individuals observed on 4 June (n = 3). Of three lactating females captured, the first was captured on 23 June, and the last was observed on 2 July. Two post-lactating females were captured on 2 July. No volant juvenile big brown bats were captured. Table 1 presents metrics for mass and forearm length by sex and reproductive stage. Forearm length was not significantly different between adult male and female big brown bats (t = 2.02, d.f. = 39, P = 0.067). Totals of 5 and 7 adult male and female northern myotis were captured, respectively, with numbers of males and females approximately equal Table 1. Number of individuals captured and mean mass and forearm length of E. fuscus (big brown bat), M. lucifugus (little brown myotis), and M. septentrionalis (northern myotis) (by age and reproductive class) captured at Pisgah State Park. nd = no data. Adult Female Sub-adult Male Pregnant Lactating Post-lactating Male Female M. lucifugus n 45 39 6 2 5 0 mass (g) 7.9 ± 0.2 8.5 ± 0.2 8.5 ± 0.4 8.3 ± 0.3 7.2 ± 0.3 nd forearm (mm) 37.5 ± 0.1 37.5 ± 0.2A 36.6 ± 0.3 nd E. fuscus n 31 4 3 2 0 0 mass (g) 15.6 ± 0.3 23.9 ± 1.2 18.5 ± 2.1 17.8 ± 1.8 nd nd forearm (mm) 44.7 ± 0.3 45.7 ± 0.5A nd nd M. septentrionalis n 5 5 2 0 0 0 mass (g) 6.5 ± 0.4 7.9 ± 0.7 7.8 ± 0.3 nd nd nd forearm (mm) 35.8 ± 0.2 36.3 ± 0.3A nd nd nd AIndicates that data from all adult female reproductive classes were combined. 2008 J.P. Veilleux, H.H. Thomas, and P.R. Moosman, Jr. 31 (binomial test, P = 0.77). All males had abdominal testes. Five pregnant females were captured between 14 May and 7 June, and two lactating females were captured on 23 and 29 June. No volant juvenile northern myotis were captured. Metrics for mass and forearm length by sex and reproductive stage are presented in Table 1. Forearm length of northern myotis was not significantly different between sexes (t = 2.22, d.f. = 10, P = 0.109). Discussion Little brown myotis was the most frequently captured species of bat at Pisgah (65% of captures). Previous survey efforts in New Hampshire reported similar results. Captures of little brown myotis from the White Mountain National Forest (north-central New Hampshire) by Krusic (1995), Sasse (1995), and Chenger (2004) represented 75% (63 of 84 captures), 71% (198 of 281), and 75% (175 of 232) of total captures, respectively. A relatively lower percent of little brown myotis captures have been reported from southern New Hampshire. LaGory et al. (2002) reported captures of 38% (11 of 29 captures) in a survey at New Boston, Hillsborough County, while Chenger (2003) found that this species comprised 41% (59 of 145) of captures in a survey in southwestern New Hampshire (Surry and Keene townships, Cheshire County). Big brown bat was the second most common species observed at Pisgah (26% of captures). These data are similar to relative abundance of big brown bats in two previous surveys in southern New Hampshire. Specifi- cally, LaGory et al. (2002) reported captures of 35% (10 of 29 captures) and Chenger (2003) found that this species comprised 28% (40 of 145) of total captures. Relative abundance of big brown bats appears lowest in north-central New Hampshire, where big brown bats represented 10%, 1%, and 12% of total captures, respectively (Chenger 2004, Krusic 1995, Sasse 1995). Northern myotis represented 8% of captures at Pisgah. Capture data for northern myotis in New Hampshire are variable. From the White Mountains, Sasse (1995) reported 27% (75 of 281 captures) as northern myotis, while Krusic (1995) and Chenger (2004) reported 12% (10 of 84 captures) and 7% (16 of 232 captures) from the same region, respectively. From southern New Hampshire, LaGory et al. (2002) reported 7% (2 of 29 captures) as northern myotis, while Chenger (2003) reported that this species comprised 22% (32 of 145 captures). Eastern red bats were apparently uncommon at Pisgah. The single capture of an eastern red bat during this study occurred early in the season, raising the possibility that the bat was migrating rather than remaining as a summer resident. Observations of eastern red bats in other regions of New Hampshire are similarly infrequent. Only 10 other individuals have been captured in the state, including seven from the White Mountains region (Chenger 2004, Sasse 1995) and two from southern New Hampshire (LaGory et al. 2002). 32 Northeastern Naturalist Vol. 15, No. 1 In the eastern United States, both little brown myotis and big brown bats roost almost exclusively in human structures (e.g., barns and attics of homes and churches; Whitaker and Hamilton 1998). Because man-made structures are rare in Pisgah, it is likely that most little brown myotis and big brown bats enter the Park to forage, but not to roost. Limited data support this hypothesis for little brown myotis. As part of a separate study, a single female little brown myotis captured from the central region of Pisgah (0.8 km southeast of Fullam Pond; Fig. 1) was fitted with a radio-transmitter to determine the location of its day roost. The bat was found roosting in an attic of a small, slate-roofed home, approximately 2.6 km SE of the capture site. An emergence count indicated a colony size of approximately 300 bats. Distribution patterns of little brown myotis and big brown bats captured at Pisgah suggest these species occur throughout the Park (Fig. 1). Numerous structures (barns, churches, and old homes) occur along roads abutting the park and likely serve as roosts for these 2 species. Because little brown myotis and big brown bats forage in openings, and along edges and corridors (Brigham and Fenton 1991, Kurta 1982), Pisgah likely provides numerous foraging sites (e.g., roads, streams, and unforested wetlands). Northern myotis likely roost and forage in the Park. A single female northern myotis was radio-tagged (also part of another study) on 7 June 2004, and 3 roost trees were located within 0.6 km of the capture site (located in the northeast section of Pisgah). An emergence count at one roost (a red maple) verified 26 bats roosting under exfoliating bark. Abundant closedcanopy forest at Pisgah is consistent with roosting and foraging requirements of northern myotis (Brack and Whitaker 2001, Ford et al. 2006). This survey indicates a relatively low diversity of bat species at Pisgah. Only three of the nine species known to occur in New Hampshire were regularly documented at the Park, with an additional capture of a single eastern red bat. Although we sampled nearly all accessible locations that offered suitable mist net sites, a large area of the Park was inaccessible. Inaccessible sites included some relatively high-elevation wetlands and rock outcrops (300–400 m elevation), and large tracts of forest with small patchy wetlands. While such limitations are inherent to most bat surveys, they may have resulted in failure to detect less common species. For example, a population of eastern small-footed myotis occurs at the Surry Mountain Dam, approximately 20 km northeast of Pisgah (Chenger 2003). This species is believed to roost in rock crevices (Best and Jennings 1997) and may have been present near exposed rock outcrops at Pisgah. Other bat species not observed during the present survey have been detected rarely during other surveys in New Hampshire. Unless work of this nature continues, diversity, distribution and life history of bats in New Hampshire will remain poorly understood. 2008 J.P. Veilleux, H.H. Thomas, and P.R. Moosman, Jr. 33 Acknowledgments Part of this research was funded by a National Science Foundation grant (DBI 0330897). We thank N. Reppucci and the New Hampshire Parks and Recreation Department for allowing access to Pisgah, as well as S.L. Veilleux, D.L. Moosman, L. Hanley-Thomas, C.K. Cratsley, and undergraduate students at Franklin Pierce and Fitchburg State Colleges for aid in fieldwork and comments on early drafts of the manuscript. 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. Barclay, R.M.R., and G.P. Bell. 1988. Marking and observational techniques. Pp. 59–76, In T.H. Kunz (Ed.). Ecological and Behavioral Methods for the Study of Bats. Smithsonian Institution Press, Washington, DC. 533 pp. Best, T.L., and J.B. Jennings. 1997. Myotis leibii. Mammalian Species 547:1–6. Brack, V., Jr., and J.O. 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