nena masthead
NENA Home Staff & Editors For Readers For Authors

The Ecology of the Wood Turtle (Glyptemys insculpta) in the Eastern Panhandle of West Virginia
Jessica Curtis and Peter Vila

Northeastern Naturalist, Volume 22, Issue 2 (2015): 387–402

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

Northeastern Naturalist Vol. 22, No. 2 J. Curtis and P. Vila 2015 387 2015 NORTHEASTERN NATURALIST 22(2):387–402 The Ecology of the Wood Turtle (Glyptemys insculpta) in the Eastern Panhandle of West Virginia Jessica Curtis1,2 and Peter Vila1,* Abstract - Glyptemys insculpta (Wood Turtle) is listed as imperiled in West Virginia and designated as endangered under the IUCN Red List. We studied a population of Wood Turtles in the Eastern Panhandle of West Virginia from May 2010 to July 2011. We captured 25 turtles at 2 sites: 12 males, 9 females, 3 juveniles, and 1 hatchling. We fitted 10 adults with radio transmitters, 9 of which also received temperature-data loggers. Our 249 total observations include the 10 initial captures of the equipped turtles with 218 subsequent radio locations, and 15 unequipped turtles that were captured, and then recaptured 6 times. Morphometrics of Wood Turtles at the study location were similar to those reported for another West Virginia population. The home range for both males and females was approximately 6 ha; there were no significant intersexual differences. Turtles entered hibernacula in late October when temperatures were approximately 10 °C and remained inactive until mid-March when temperatures were approximately 5 °C. Our study provides a baseline assessment of the Wood Turtle in an unstudied upper-elevation Eastern Panhandle location. Introduction Glyptemys insculpta (LeConte) (Wood Turtle) is found in disjunct, remnant populations extending from eastern Minnesota and northern Iowa to southern Québec and south to northern Virginia and West Virginia (Ernst et al. 1994, Harding and Bloomer 1979, Tessier et al. 2005). Wood Turtles are well studied across their range (Bowen and Gillingham 2004, Ernst et al. 1994). Like many temperate reptiles (Ashton and Feldman 2003), Wood Turtles exhibit latitudinal gradients in various life-history and morphological traits (Brooks et al. 1992, Walde et al. 2003). The Wood Turtle appears to be declining in some portions of its range (Daigle and Jutras 2005, Garber and Burger 1995, Saumure et al. 2007). As with many species of reptiles, Wood Turtles are threatened primarily by the destruction and degradation of preferred habitat (Garber and Burger 1995, Gibbon et al. 2000). Moreover, life-history characteristics make turtles particularly sensitive to disturbances; in the case of Wood Turtles, individuals are long-lived (up to 58 years), recruitment is low, and breeding begins at a relatively old age (up to 20 years) (Ernst et al. 1994, Harding and Bloomer 1979). Due to declining populations, the Wood Turtle is classified as endangered on the IUCN Red List (Van Dijk and Harding 2011). In West Virginia, the Wood Turtle occurs only in the Eastern Panhandle and is considered a high priority species for conservation efforts where it is ranked as an S3 or vulnerable species 1Shepherd University, Department of Environmental Studies, Shepherdstown, WV 25443. 2Current address - Marshall University, Biology Department, One John Marshall Drive, Huntington, WV 25755. *Corresponding author - pvila@shepherd.edu. Manuscript Editor: Todd Rimkus Northeastern Naturalist 388 J. Curtis and P. Vila 2015 Vol. 22, No. 2 (Sargent 2014). Establishing baseline Wood Turtle population data is especially important in the Eastern Panhandle of West Virginia due to a human-population increase of 27% between 2000 and 2010 and recent rapid economic development in the region (US Census Bureau 2012). Wood Turtles are not well studied in West Virginia; 2 earlier studies (Breisch 2006, Niederberger and Seidel 1999) looked at Wood Turtles in low-gradient and low-elevation riverine habitat in the Eastern Panhandle. This study describes the Wood Turtle at the southern part of its range in West Virginia at a higher-elevation headwater location. The objective of this study was to describe the natural history of the Wood Turtle at this upperelevation Eastern Panhandle location, including aspects of: (1) demography, (2) morphometrics, (3) home-range size, (4) distance traveled from water, (5) habitat use, and (6) thermal regime. Methods Study site We studied Wood Turtles at 2 locations along the same stream in the Eastern Panhandle of West Virginia. To protect these animals, we do not provide exact site locations. Sites were at ~305 m elevation and separated by 8.8 km and a reservoir. One surveyed area was ~2.4 km upstream of the reservoir, and the other was ~6.4 km downstream of the reservoir. Capture and radiotelemetry We initially located Wood Turtles by following transects parallel to the stream up to 200 m from the water and capturing them opportunistically by hand. We found basking traps and drift fences to be ineffective capture methods. We recorded Wood Turtle capture coordinates with a Garmin 76CSx GPS unit (Garmin, Olathe, KS). We visited sites approximately 5 days per week in summer and 3 days per week in fall. From October 2010 to early March 2011, shortly before the turtles emerged from their hibernacula, we visited sites approximately once a month. We recorded mass, minimum straight-line carapace length, carapace width, minimum straight-line plastron length, plastron width, height at bridge, and number of annuli for all Wood Turtles. We determined gender by secondary sexual characteristics (Harding and Bloomer 1979). We considered Wood Turtles to be juveniles if the carapace was less than 160 mm long or their mass was less than 600 g (Lovich et al. 1990); young Wood Turtles with no annuli were designated as hatchlings. We also noted deformities, injuries, and missing limbs. Employing a modified Cagle (1939) numbering system to distinguish individuals, we used a file to notch 1 or 2 marginal scutes of all Wood Turtles captured. We affixed radio transmitters (Model # R1930, Advanced Telemetry Systems, Isanti, MN) with PC-11 epoxy (Part # 010112, Protective Coating Company, Allentown, PA) to 10 adult Wood Turtles (5 males and 5 females) on the posterior portion of the carapace at the edge of the marginal and the costal scutes. The transmitters weighed 24 g each and together with the epoxy, added approximately 35 g to the mass of each turtle. Northeastern Naturalist Vol. 22, No. 2 J. Curtis and P. Vila 2015 389 We relocated Wood Turtles with transmitters approximately twice a week during the summer of 2010, every 2 weeks during the fall of 2010, and approximately every 2 weeks in the spring and summer of 2011. We removed radio transmitters and data loggers in July 2011. Temperature loggers We attached temperature loggers (Onset HOBO Data Logger, Model #UA-002- 8K, Bourne, MA) to 9 of the 10 Wood Turtles with radio transmitters. We glued an aluminum L bracket—with the front edge rounded to the same shape as the HOBO temperature logger—to the edge of the marginal and the costal scutes on the opposite side of the transmitter using PC-11 epoxy. The eyelet of the temperature logger fit through a hole in the bracket and we secured the loggers to the brackets with a cotter pin that allowed each logger to swivel in its metal cradle. This arrangement allowed data to be downloaded in the field without removing the loggers from the Wood Turtles. Each data logger, with bracket and glue weighed approximately 40 g. Three temperature loggers, including the glue and bracket, fell off during the study. The combined mass of the transmitter, temperature logger, bracket, and epoxy on all but one Wood Turtle was 5–8% of the turtle’s mass (Cochran 1980). Though the combined total mass of the logger and transmitter apparatus represented 9.4% of the mass of the smallest Wood Turtle (800 g), we did not observe any mobility issues with this animal. Home range and maximum distances We determined Wood Turtle home-range size using the kernel density and the minimum convex polygon methods in Geospatial Modeling Environment software (http://www.spatialecology.com/gme/) (Beyer 2012) from Wood Turtle coordinates. The kernel density method used the smoothed cross-validation method (SCV) bandwidth estimation (R Core Team 2013). The area of the 95% volume contour was calculated in ArcMap (ESRI, Redlands CA, Version 10.0) using X-tools Pro (Data East LLC, Russian Federation, Version 9.2). We used ArcMap to measure maximum travel distances from GPS capture points to the stream or other aquatic habitats utilizing the National Hydrography Dataset (USGS 2010). Habitat characterization We documented the surrounding habitat (1-m diameter) at each Wood Turtle capture location. We characterized terrestrial habitats by basic plant-community type, and aquatic habitats by the form and intermittency of habitat (Table 1; Arvisais et al. 2002, Forsythe et al. 2004). We recorded ambient air temperature at each Wood Turtle capture location. Statistical analysis We used Sigmaplot (SigmaPlot, Systat Software, San Jose, CA) for statistical analyses. A Shapiro-Wilk normality test and an equal variance test were applied to data prior to statistical analyses when comparing means. If data were normal and passed the variance test, we conducted an ANOVA; if the normality or the equal Northeastern Naturalist 390 J. Curtis and P. Vila 2015 Vol. 22, No. 2 variance test failed, we utilized a Kruskal-Wallis ANOVA on ranks analysis. We employed the Holm-Sidak method for all pairwise multiple comparison procedures to control for Bonferroni inequality and tested the ratio of male to female Wood Turtles using Yates’ χ² test. Statistical significance was set at P < 0.05 for all analyses. Results We captured 25 Wood Turtles: 12 males, 9 females, 3 juveniles, and 1 hatchling. The 249 total observations included the 10 initial captures of the equipped Wood Turtles with 218 subsequent radio locations, and 15 unequipped Wood Turtles that were captured and then recaptured 6 times. We observed Wood Turtles in 2 areas: downstream of the reservoir (downstream site) and upstream of the reservoir (upstream site). We captured 22 different Wood Turtles at the upstream site: 11 males, 7 females, 3 juveniles, and 1 hatchling; whereas, 3 different turtles were caught at the downstream site—2 females and 1 male. We observed no between-site movement by any Wood Turtle. The adult male:female sex ratio of the Wood Turtles captured at the study locations was 1.3:1 and did not differ significantly from 1:1 (Yates’ χ², P = 0.321). Juveniles and hatchlings comprised 16% of all Wood Turtles captured; excluding the hatchlings, which have a high first-year mortality rate, juveniles comprised 12.5% of all Wood Turtles captured. Influence of methods on Wood Turtles We observed no mortality in any of the notched Wood Turtles or those with transmitters. The presence of transmitters or loggers did not seem to hinder movement, and all Wood Turtles maintained their initial mass or gained mass throughout Table 1. Description of vegetation and habitat types. Many terrestrial sites included multiple canopy levels. Habitat type Description Aquatic Stream Any flowing body of water. Wetland Any non-flowing, permanent body of water. Oxbow/vernal pool Any non-flowing, seasonal body of water. Terrestrial Forest Dominant canopy over the capture location composed of trees of various species or ages. Shrubs Dominant canopy over the capture location is woody vegetation of any age or species. Could contain a partial upper level tree canopy. Shrubs mixed with herbaceous Dominant canopy over the capture location is woody vegetation mixed with herbaceous vegetation, including grasses. Could contain a partial upper level tree canopy. Herbaceous (including grasses) Dominant canopy over the capture location is herbaceous vegetation, including grasses. Could contain a partial tree canopy, but does not contain shrubs. Open Bare soil or leaf litter with no vegetation at any level. Road Open soil or gravel road. Northeastern Naturalist Vol. 22, No. 2 J. Curtis and P. Vila 2015 391 the study period. Moreover, transmitters and data loggers did not appear to prevent courtship because we observed Wood Turtles with radio transmitters and data loggers mating. Morphometrics Mean carapace length was significantly greater for males (190.6 mm) than for females (178 mm) (F = 8.78; df = 1, 19; P = 0.008). No other characteristics were significantly different between males and females (Table 2). In our study area, the smallest minimum plastron length (MPL) associated with secondary sexual traits was 151 mm; the smallest minimum carapace length was 176 mm. We could not establish minimum size at maturity for females in the study because we observed no females laying eggs nor did we palpate for eggs. The smallest female and male observed courting had a minimum carapace length of 184 mm and 186 mm, respectively. Injuries, deformities, and parasites All adult Wood Turtles (>600 g) had minor carapace damage with chips in the marginal scutes; 1 turtle exhibited a slice that cut through its first marginal scute. Three adult Wood Turtles (12.5%) were missing 1 limb. We did not observe a predation attempt and could not determine the cause of limb loss. Two Wood Turtles had eye injuries: one with an eye that was infected, pustulent, and swollen throughout the study period; this turtle remained active and feeding in summer and successfully emerged from hibernation in the spring of 2011. The eye injury of the second Wood Turtle was old and well healed; the injury modified the round pupil into a keyhole shape and the pupil did not have the ability to contract or dilate. Three Wood Turtles (12.5%) had abnormal carapacial scute arrangements: 2 Wood Turtles had extra marginal scutes, and one had an extra central scute. Although we observed mosquitoes on and surrounding Wood Turtles, we found no external parasites such as Hirudinea sp. (leeches) on any of the animals. Table 2. Morphometric data for all Wood Turtles at the study site. Mean ± standard deviation and range are reported. Adult female Adult male Juvenile Hatchling (n = 9) (n = 12) (n = 3) (n = 1) Weight (g) 890 ± 155.0, 997.1 ± 95.3, 341.7 ± 231.0, 9 680–1100 830–1150 155–600 Carapace length (mm) 178.0 ± 10.3, 190.6 ± 9.1, 126.7 ± 30.7, 39 166–196 176–205 98–159 Carapace width (mm) 130.2 ± 7.0, 135.8 ± 8.1, 96.3 ± 18.2, - 121–141 124–150 80–116 Plastron length (mm) 159.8 ± 8.3, 163.3 ± 6.4, 115.3 ± 26.4, 34 147–168 151–172 92–144 Plastron width (mm) 108.8 ± 10.7, 107.2 ± 7.4, 77.3 ± 14.3, - 95–132 94–120 65–93 Height at bridge (mm) 61.9 ± 6.4, 64.5 ± 7.9, 45.0 ± 6.1, - 51–71 58–86 41–52 Northeastern Naturalist 392 J. Curtis and P. Vila 2015 Vol. 22, No. 2 Home-range size The kernel density home-range estimate for females and males was 5.5 ha and 7.1 ha, respectively (Table 3), and was not significantly different between the sexes (F = 0.794, df = 1, 8; P = 0.399). Home-range estimates with the minimum convex polygon (MCP) method were lower—2.7 ha for females and 2.6 ha for males—and were not significantly different between the sexes (F = 0.022, df = 1, 8; P = 0.887). Home ranges were elongated, with significant overlap between Wood Turtles. Maximum distance from water Females travelled farther from any water body than males, with a mean maximum distance of 97 m for females versus a mean maximum distance of 46 m for males (F = 8.99; df = 1, 8; P = 0.017). However, females did not travel farther from the permanent aquatic pools in the mainstem stream than males—173 m versus 103 m, respectively (F = 3.57; df = 1, 8; P = 0.096; Table 4). Non-riparian habitat use At the upstream site, a clear-cut grassy field bordered a tributary of the mainstem. Three radio-tagged Wood Turtles utilized this field on multiple occasions; stays lasted as long as a week before the animals returned to the mainstem of the stream. The Wood Turtles exploited this area from May to September, but spent more time in the vicinity during the Rubus fruticosus L. (Shrubby Blackberry) fruiting season. We observed all 3 Wood Turtles eating blackberries or with presumed blackberry stains on their mouths while the plants were fruiting. Habitat use and activity In winter, Wood Turtles used only stream habitats (Fig. 1). In the spring and fall, stream use was similar (46 and 54%, respectively), while percent time in stream habitat decreased to 28% in summer. Increased use of stream habitat in the fall may have been due to preparation to enter winter hibernacula. In the warmer summer period, Wood Turtles spent less time in the stream habitat as they foraged in the surrounding forest, and we encountered them in additional habitats as they increased Table 3. Home ranges calculated with the kernel density (KD) and minimum convex polygon (MCP) method for the 10 radio-telemetered Wood Turtles. Mean ± standard deviation is reported for each sex class. *Male turtle 20 was located 1 km away, and the home range was calculated without this distant coordinate and with the distant coordinate (in parenthesis). Number of Home range (ha) Number of Home range (ha) Females sightings KD MCP Males sightings KD MCP 3 38 6.9 4.7 2 31 5.9 3.3 6 17 5.7 2.2 4 30 4.8 2.7 8 19 8.2 3.3 5 24 6.5 2.7 10 22 4.1 2.2 7 22 5.2 2.2 60 15 2.5 0.9 20* 8 (10) 13.3 (57.8) 1.9 (13.7) 5.5 ± 2.2 2.7 ±1.4 7.1 ± 3.1 2.6 ± 0.5 (16.0 ± 23.4) (4.9 ± 4.9) Northeastern Naturalist Vol. 22, No. 2 J. Curtis and P. Vila 2015 393 their activity (Fig. 1). Wood Turtle activity varied with season (Table 5) and is summarized below. Winter. The winter inactive stage included all time spent in the hibernacula. During this time, Wood Turtles were entirely aquatic and all of the Wood Turtles we captured were in a stream habitat (Table 5). Wood Turtles did not utilize the permanent wetlands habitat as a hibernaculum. We located all radio-tagged Wood Turtles in the mainstem and not in any of the tributaries. Table 4. Maximum distance from water is the straight-line distance from the capture coordinates to the nearest water source, determined with ArcMap. Turtle # Maximum distance from water (m) Maximum distance from stream (m) Females 3 146.9 272.8 6 64.7 143.6 8 111.5 130.3 10 60.0 201.4 60 101.8 115.6 Mean ± SD 97.0 ± 35.3 172.7 ± 64.7 Males 2 49.8 87.1 4 35.9 50.9 5 50.8 166.7 7 63.2 66.0 20* 27.6 146.0 Mean ± SD 45.5 ± 13.9 103.3 ± 50.6 *Male turtle 20 was located 1 km away and this distance was not used in the calculation of the maximum distance from water or stream. Figure 1. Percent of Wood Turtle captures by habitat type. The category “other” includes wetland, oxbow/vernal pool, open, and road. Northeastern Naturalist 394 J. Curtis and P. Vila 2015 Vol. 22, No. 2 Spring. After emergence, Wood Turtles stayed close to the aquatic habitat at a maximum distance from water of 52 m. We observed that Wood Turtles utilized aquatic and terrestrial habitats approximately equally: 46% and 54%, respectively. Summer. In the active summer stage, Wood Turtles foraged at greater distances from the stream (147 m), and we observed them foraging at a greater number of terrestrial habitats than in other seasons: 6 habitats in summer, 5 in spring, and 4 in fall (Fig. 1). Terrestrial habitat use during this period was 70% compared with 30% aquatic habitat use. Fall. The fall stream-restricted active stage was similar to the spring stage, with activity limited to a narrow band around the stream as Wood Turtles prepared to enter hibernacula. In the fall, Wood Turtles were closer to the stream than in the spring (40 m versus 52 m, respectively), and we observed them spending slightly more time in the aquatic habitat than the terrestrial habitat (54% versus 44%, respectively). We observed 3 instances of courtship at this time. Hibernacula Of the 10 adult Wood Turtles outfitted with radio transmitters, we radio-tracked 9 of them to their hibernacula. We observed no Wood Turtles overwintering in an exposed location and detected no Wood Turtle movement during the inactive period. Eight hibernacula were located upstream of the lake; 6 were clustered together and 2 hibernacula were ~0.5 km further upstream. The other hibernaculum was at the downstream site. Hibernacula were located in ~1-m-deep pools that consisted of undercut banks with or without snags and other debris. Ondatra zibethicus L. (Muskrat) and Castor canadensis Kuhl (Beaver) had modified the stream banks in some hibernacula locations. One hibernaculum contained at least 3 adult Wood Turtles (1 radio-tagged, 2 untagged). After careful searching, we found that the other 8 hibernacula contained only 1 Wood Turtle. Some hibernacula, located in burrows with separate entrances, were very close to one another (approximately 0.5–3 m). We could not ascertain whether the burrow entrances connected to a larger interior chamber and therefore treated these hibernacula as distinct. All identified hibernacula were found in the mainstem stream. Sites used as hibernacula were also utilized during the summer period. These sites are deeper areas in the mainstem that did not dry up during the summer period; availability of these deeper sites was limited within the study area. Table 5. Distance travelled from water and the percent of time in aquatic habitat during the activity stages. Maximum distance = maximum distance of any turtle from water within activity period. Stage Months Maximum distance (m) Percent aquatic Winter Late October–mid-March 0 100% Spring Mid-March–mid-May 52 46% Summer Mid-May–mid-September 147 30% Fall Mid-September–late October 40 54% Northeastern Naturalist Vol. 22, No. 2 J. Curtis and P. Vila 2015 395 Thermal regime We observed 4 distinct temperature periods (Fig. 2): (1) temperature declined from ~25 °C in July 2010 to approximately 17 °C in late September 2010, (2) temperature then declined to almost 0 °C in early December 2010, (3) temperature stayed at ~0 °C until mid-February 2011, and (4) temperature increased to ~25 °C in July 2011. Five-degree to 25 °C variations were superimposed on this general trend. Turtles were in hibernacula from late October 2010, when the temperature was approximately 10 °C, until mid-March 2011, when the temperature reached 5 °C. The highest temperature recorded on basking Wood Turtles was 42 °C. We have 63 simultaneous readings of logger temperature, ambient air temperature, and habitat at time of capture; 32 readings from 4 males and 31 readings from 4 females. Aquatic Wood Turtle logger mean temperatures (°C) for spring, summer, fall, and winter were 20.9 (n = 2), 23.1 (n = 4), 20.0 (n = 11), and 6.7 (n = 2), respectively; logger temperatures were within 5 degrees of ambient air temperature. Terrestrial Wood Turtle logger mean temperatures (°C) for spring, summer, and fall were 37.0 (n = 2), 28.8 (n = 17), and 25.1 (n = 25), respectively; logger temperatures were within 8 degrees of ambient air temperature. Discussion Morphometrics Adult Wood Turtles tend to have greater mean carapace lengths with increasing latitude (Brooks et al. 1992, Walde et al. 2003). The morphometrics of the Wood Turtles in this study area were similar to populations studied at similar latitudes Figure 2. Temperature data for a representative Wood Turtle at the upstream site for which we collected a complete seasonal data set from 15 Jul 2010 to 31 Jul 2011. The different monthly spacing is due to different temperature-recording intervals; temperature was recorded every 2 min during the summer and every 15 min during the fall and winter. The straight line is a line drawn to indicate temperature periods. Northeastern Naturalist 396 J. Curtis and P. Vila 2015 Vol. 22, No. 2 (Breisch 2006, Lovich et al. 1990). We did not find larger morphometric characteristics due to expected altitudinal decreases in temperature. As seen in other Wood Turtle populations, male carapace length at our study sites was significantly larger than female carapace length: New Jersey (Breisch 2006); Michigan (Farrell and Graham 1991, Harding and Bloomer 1979); New Hampshire (Harding and Bloomer 1979); Ontario (Tuttle and Carroll 1997, Brooks et al. 1992); and Quebec (Walde et al. 2003). Development of secondary sexual traits in male Wood Turtles coincides with maturation (Harding and Bloomer 1979). The smallest minimum plastron length (MPL) and smallest minimum carapace length (MCL) at maturation are expected to increase with latitude (Brooks et al. 1992, Farrell and Graham 1991, Walde et al. 2003). However, our smallest male displaying secondary sexual characteristics —MPL = 151 mm and MCL = 176 mm—was similar to the smallest MCL reported by Ross et al. (Ross et al. 1991) in Wisconsin but larger than Breich (2006) in a regional West Virginia location. Injuries, deformities, and parasites Missing appendages are common in Wood Turtle populations and are likely due to aborted predation attempts (Saumure and Bider 1998, Saumure et al. 2007). Our observation of 12.5% amputation is high compared to many other sites: 6% in West Virginia (Breisch 2006), 8.6% in New Jersey (Farrell and Graham 1991), 6.8% in Pennsylvania (Ernst 2001), 4.5% in New York (Hunsinger 2002), 9% in New Hampshire (Tuttle 1996), 9.7% in Michigan (Harding and Bloomer 1979), 12.5% in a later Michigan study (Harding 1985), and 9.6% in Quebec (Walde et al. 2003). Studies reporting higher amputation were sites impacted by agricultural or recreational activities (15% and 32% at 2 different sites in Quebec [Saumure and Bider 1998] and 35.5% in Vermont [Parren 2013]). Direct observations and incidental evidence implicate Procyon lotor (L.) (Raccoon) in the mutilation of adult Wood Turtles (Harding 1985). We never directly observed Raccoons at our study site, but we found their footprints and partially eaten prey items. Martes pennanti (Erxleben) (Fisher; Parren 2013) and Lontra canadensis (Schreber) (North American River Otter; Carroll and Ultsch 2006) have also been implicated in Wood Turtle mutilation and death, but we did not observe activity of either species in the study area. Our site has minimal impact by agricultural machinery because the nearby clearcut site is mowed only once a year. In agricultural areas, mortality caused by machinery is a significant problem (Saumure and Bider 1998, Saumure et al. 2007). Increased predation by mesopredators in edge habitats, like Mephitis mephitis (Schreber) Striped Skunk and Raccoon (Ross et al. 1991, Saumure and Bider 1998), were likely minimized in this study area given that the clear-cut areas are surrounded by forest and not anthropogenic edge habitats where their diets would have been supplemented by humans. However, predator density may be increased by the clearcut area; this possibility coupled with the higher capture probability of injured Wood Turtles may explain the high percentage of amputees observed. Northeastern Naturalist Vol. 22, No. 2 J. Curtis and P. Vila 2015 397 The 12.5% frequency of abnormal scute arrangements observed in this study was within the range found in other studies: 14% in West Virginia (Breisch 2006), 4.5% in Pennsylvania (Ernst 2001), and 2% in Michigan (Harding and Bloomer 1979). Scute-arrangement abnormalities do not appear to reduce fitness in affected turtles (Harding and Bloomer 1979). Leeches are frequently reported on Wood Turtles. Breisch (2006) found that 16% of Wood Turtles studied had leeches at least once, and Niederberger and Siedel (1999) reported that Wood Turtles in water were “often (>50%)” parasitized by leeches, although they did not provide the overall incidence of parasitism for all captures or the number of individuals parasitized. Infestation rates were much higher in Pennsylvania at 38.6% (Ernst 2001) and almost 90% in New Jersey (Farrell and Graham 1991). These rates differ from our study, during which we observed no leeches on Wood Turtles; it may be that headwater streams at this location have low leech density. Leeches on Wood Turtles are generally observed when Wood Turtles are in aquatic habitats from October to May (Breisch 2006, Hulse and Routman 1982, Koffler et al. 1978, Tuttle and Carroll 1997). However, the majority of our captures were between May and October when Wood Turtles were predominantly in terrestrial habitats and encounters with leeches would be low. Leech parasitism could be high for the October to May period, but direct observation of Wood Turtles is more difficult in deeper waters or in hibernacula. Home range and habitat use Mean home-range sizes in this study were small and within the ranges reported for Wood Turtles of both genders; home-range size follows latitudinal gradients, with smaller ranges in the South and larger ranges in the North (Bowen and Gillingham 2004, Remsberg et al. 2006). It is likely that habitat quality at our study site is high and not limiting (Arvisais et al. 2002). Maximum distance from water was similar to other West Virginia populations at ~200 m (Breisch 2006, Niederberger and Seidel 1999), but smaller than distances for Wood Turtles in Vermont (425 m; Parren 2013) or for Wood Turtles in Pennsylvania (600 m; Kaufmann 1995). The wider dispersal from permanent water bodies seen in females did not appear to be associated with a search for suitable nesting sites as reported by several authors for various turtle species (Lewis and Faulhaber 1999, Morreale et al. 1984, Quinn and Tate 1991). Rather, movement was frequently associated with rainfall and may have been related to foraging activities that capitalized on increased numbers of invertebrate prey available after rainfall (Kaufmann 1989). As indicated by the small range-size, the small maximum distance from water traveled by our Wood Turtles indicates high-quality forage near water (Arvisais et al. 2002). Upland-site fidelity has been documented in both genders (Parren 2013, Remsberg et al. 2006). It is possible that extended movement away from water by females could be due to idiosyncratic differences between individuals and not an effect of gender (Compton et al. 2002). Increasing sample size and measurements over several seasons would allow for a more precise discernment of movement Northeastern Naturalist 398 J. Curtis and P. Vila 2015 Vol. 22, No. 2 patterns between sexes and allow hypotheses concerning Wood Turtle movement to be tested. Wood Turtle habitat use in this study was similar to habitat use described for other eastern Wood Turtle populations (Harding and Bloomer 1979). It included permanent streams with a mosaic of forest and open-canopy habitats adjacent to the stream (Ernst et al. 1994, Jones and Sievert 2009). Wood Turtles in our studies shared the same active period and terrestrial period as animals at other sites in the species’ southern range (Breisch 2006, Kaufmann 1992, Niederberger and Seidel 1999). In our study, Wood Turtles spent approximately equal time in stream and terrestrial habitats in the spring and fall most likely due to the ability to reliably thermoregulate in the stream corridor during these periods of wide temperature fluctuations (Compton et al. 2002, Dubois et al. 2009). Use of stream habitat in the fall may also be due to preparation to enter winter hibernacula, and this fall congregation is when we observed courting. The clear-cut area at our site, which was utilized by 3 different Wood Turtles during the summer, may also provide foraging and thermogegulatory habitat for Wood Turtles (Compton et al. 2002, Dubois et al. 2009) and providing similar habitats could be a useful management tool for this species. We found low numbers of Wood Turtles (1–3) in hibernacula in this study compared to those at other sites that contained 5–70 turtles in a single occluded hibernaculum (Bloomer 1978, Harding and Bloomer 1979). While Wood Turtles have been observed overwintering exposed on stream beds in Massachusetts (Farrell and Graham 1991) and in Ontario (Greaves and Litzgus 2008), individuals at our site used some type of cover. Wood Turtles in our study area may have been limited by the number of permanent aquatic habitats available for hibernacula. Wood Turtles appeared to be restricted to stretches of the mainstem of the creek that do not dry up in the summer, including flooded areas behind beaver dams. Beaver dams were located above and below the lake, and we observed Wood Turtles utilizing these areas. Damming activities by Beavers provide aquatic habitat throughout the year; thus, Beavers may be functioning as a keystone species in the study area. Thermal regime The 1–8 °C difference found between temperatures on the Wood Turtles’ data loggers and the ambient air temperatures is similar to differences found by for Wood Turtles in Lancaster County, PA (Ernst 1986). Although Wood Turtles thermoregulate, regulation is imprecise even at their northern range limit where they would be expected to be thermally constrained (Dubois et al. 2009). Population viability and future directions Low recapture rates precluded accurate estimates of the Wood Turtle population in the study area; however, given the low number of Wood Turtles captured, the population is most likely small—likely smaller than populations in other parts of the state (Niederberger and Seidel 1999). Juvenile Wood Turtles are typically Northeastern Naturalist Vol. 22, No. 2 J. Curtis and P. Vila 2015 399 not captured (Daigle 1997, Ross et al. 1991). Our observation of 3 juveniles and 1 hatchling along with the observation of no observed adult mortality suggested persistence of Wood Turtles at the study site. Further research is required to determine if recruitment into the adult cohort is occurring because our data showed that the hatchling/juvenile to adult ratio is low. While low numbers may indicate declining or relict populations with a concomitant loss of genetic diversity, it may be that habitat availability is limiting in the study area and cannot sustain a large Wood Turtle population. High levels of polymorphism and heterozygosity may still be maintained in small populations (less than 50; Tessier et al. 2005), so this population although likely to be small, could maintain genetic diversity. The reservoir is probably a barrier to movement because we observed no movement across the lake. Additionally, Wood Turtles did not utilize terrestrial habitats adjacent to the lake, suggesting these 2 groups may be relict populations separated by reservoir formation. This study documented a baseline count of the Wood Turtles; further study is warranted in order to determine reproduction, recruitment, and population viability. While determination of population size, structure, and viability of Wood Turtles in protected private and public areas is needed, there is also a need to investigate the status and viability of Wood Turtle populations across the wider landscape. Habitat destruction and degradation (Ernst et al. 1994, Garber and Burger 1995, Gibbon et al. 2000) pose the greatest threats to Wood Turtles. Populations that occupy less-protected habitats located in areas impacted by development and agricultural activity are at the greatest risk. Important questions for the maintenance of a viable, regional Wood Turtle metapopulation remain, including whether there is genetic exchange between nearby populations and what, if any, connectivity of the Wood Turtles described in this study have to the regional metapopulation. Acknowledgments We gratefully acknowledge the assistance of Larry Hines, whose knowledge of the area and wildlife and enthusiasm and logistical support were instrumental for the success of this study. We also express our appreciation to Alan Temple at the US Fish and Wildlife Service for use of the radiotelemetry equipment that made this study possible. This study was funded by a grant from the West Virginia Department of Natural Resources. Both authors contributed equally to this paper. Literature Cited Arvisais, M., J.-C. Bourgeois, E. Lévesque, C. Daigle, D. Masse, and J. Jutras. 2002. Home range and movements of a Wood Turtle (Clemmys insculpta) population at the northern limit of its range. Canadian Journal of Zoology 80:391–398. Ashton, K.G., and C.R. Feldman. 2003. Bergmann’s rule in nonavian reptiles: Turtles follow it, lizards and snakes reverse it. Evolution 57:1151–1163. Beyer, H.L. 2012. Geospatial Modelling Environment. Available online at http://www. spatialecology.com/gme. Accessed 1 July 2013. Bloomer, T.J. 1978. Hibernacula congregating in the Clemmys genus. Journal of North Ohio Association of Herpetology 4:37–42. Northeastern Naturalist 400 J. Curtis and P. Vila 2015 Vol. 22, No. 2 Bowen, K.D., and J.C. Gillingham. 2004. R9 Species Conservation Assessment for Wood Turtle – Glyptemys insculpta (LeConte, 1830). Conservation Assessment. Eastern Region of the US Forest Service, Milwaukee, WI. Breisch, A.N. 2006. The natural history and thermal ecology of a population of Spotted Turtles (Clemmys Guttata) and Wood Turtles (Glyptemys Insculpta) in West Virginia. M.Sc. Thesis. Marshall University, Huntington, WV. Brooks, R.J., C.M. Shilton, G.P. Brown, and N.W.S. Quinn. 1992. Body size, age distribution, and reproduction in a northern population of Wood Turtles (Clemmys insculpta). Canadian Journal of Zoology 70:462–469. Cagle, F.R. 1939. A system of marking turtles for future identification. Copeia 3:1 70–173. Carroll, D.M., and G.R. Ultsch. 2006. Glyptemys insculpta (Wood Turtle): Predation. Herpetological Review 37:215–216. Cochran, W.W. 1980. Wildlife telemetry. Pp. 507–520, In S.D. Schemnitz (Ed.). Wildlife Techniques Manual. The Wildlife Society, Inc., Washington, DC. 1136 pp. Compton, B.W., J.M. Rhymer, and M. McCollough. 2002. Habitat selection by Wood Turtles (Clemmys Insculpta): An application of paired logistic regression. Ecology 83:833–843. Daigle, C. 1997. Size and characteristics of a Wood Turtle, Clemmys insculpta, population in southern Québec. Canadian Field Naturalist 111:440–444. Daigle, C., and J. Jutras. 2005. Quantitative evidence of decline in a southern Québec Wood Turtle (Glyptemys insculpta) population. Journal of Herpetology 39:130–132. Dubois, Y., G. Blouin-Demers, B. Shipley, and D. Thomas. 2009. Thermoregulation and habitat selection in Wood Turtles Glyptemys insculpta: Chasing the sun slowly. Journal of Animal Ecology 78:1023–1032. Ernst, C.H. 1986. Environmental temperatures and activities in the Wood Turtle, Clemmys insculpta. Journal of Herpetology 20:222–229. Ernst, C.H. 2001. Some ecological parameters of the Wood Turtle, Clemmys insculpta, in southeastern Pennsylvania. Chelonian Conservation and Biology 4:94–99. Ernst, C.H., R.W. Barbour, and J.E. Lovich. 1994. Turtles of the United States and Canada. Smithsonian Institution Press, Washington, DC. 682 pp. Farrell, R.F., and T.E. Graham. 1991. Ecological notes on the turtle Clemmys insculpta in Northwestern New Jersey. Journal of Herpetology 25:1–9. Forsythe, P., B. Flitz, and S.J. Mullin. 2004. Radio telemetry and post-emergent habitat selection of neonate Box Turtles (Emydidae: Terrapene carolina) in central Illinois. Herpetological Review 35:333–335. Garber, S.D., and J. Burger. 1995. A 20-yr study documenting the relationship between turtle decline and human recreation. Ecological Applications 5:1151–1162. Gibbon, J.W., D.E. Scott, T.J. Ryan, K.A. Buhlmann, T.D. Tuberville, B.S. Metts, J.L. Greene, T. Mills, Y. Leiden, S. Poppy, and C.T. Winne. 2000. The global decline of reptiles, déjà vu amphibians. BioScience 50:653–666. Greaves, W.F., and J.D. Litzgus. 2008. Chemical, thermal, and physical properties of sites selected for overwintering by northern Wood Turtles (Glyptemys insculpta). Canadian Journal of Zoology 86:659–667. Harding, J.H. 1985. Clemmys insculpta, Wood Turtle predation–mutilation. Herpetological Review 161:30. Harding, J.H., and T.J. Bloomer. 1979. The Wood Turtle, Clemmys insculpta: A natural history. Bulletin of the New York Herpetological Society 15:9–26. Hulse, A.C., and E.J. Routman. 1982. Leech (Placobdella parasitica) infestations on the Wood Turtle, Clemmys insculpta. Herpetological Review 13:116–117. Northeastern Naturalist Vol. 22, No. 2 J. Curtis and P. Vila 2015 401 Hunsinger, T.W. 2002. Demography and life history of a WoodTurtle (Clemmys insculpta) population in the Hudson River watershed. Section VIII:1–25, In W.C. Neider and J.R. Waldman (Eds.). Final Reports of the Tibor T. Polgar Fellowship Program, 2001. Hudson River Foundation, New York, NY. Jones, M.T., and P.R. Sievert. 2009. Effects of stochastic flood disturbance on adult Wood Turtles, Glyptemys insculpta, in Massachusetts. Canadian Field-Naturalist 123:313–322. Kaufmann, J.H. 1989. The Wood Turtle stomp. Natural History 98:8–13. Kaufmann, J.H. 1992. Habitat use by Wood Turtles in central Pennsylvania. Journal of Herpetology 26:315–321. Kaufmann, J.H. 1995. Home ranges and movements of Wood Turtles, Clemmys insculpta, in Central Pennsylvania. Copeia 1995:22–27. Koffler, B.R., R.A. Seigel, and M.T. Mendonça. 1978. The seasonal occurrence of leeches on the Wood Turtle, Clemmys insculpta (Reptilia, Testudines, Emydidae). Journal of Herpetology 12:571–572. Lewis, T.L., and C.A. Faulhaber. 1999. Home ranges of Spotted Turtles (Clemmys guttata) in southwestern Ohio. Chelonian Conservation and Biology 3:430–434. Lovich, J.E., C.H. Ernst, and J.F. McBreen. 1990. Growth, maturity, and sexual dimorphism in the Wood Turtle Clemmys insculpta. Canadian Journal of Zoology 68:672–677. Morreale, S.J., J.W. Gibbons, and J.D. Congdon. 1984. Significance of activity and movement in the Yellow-bellied Slider Turtle (Pseudemys scripta). Canadian Journal of Zoology 62:1038–1042. Niederberger, A.J., and M.E. Seidel. 1999. Ecology and status of a Wood Turtle (Clemmys insculpta) population in West Virginia. Chelonian Conservation and Biology 3:414–418. Parren, S.G. 2013. A twenty-five-year study of the Wood Turtle (Glyptemys insculpta) in Vermont: Movements, behavior, injuries, and death. Herpetological Conservation and Biology 8:176–190. Quinn, N.W.S., and D.P. Tate. 1991. Seasonal movements and habitat of Wood Turtles (Clemmys insculpta) in Algonquin Park, Canada. Journal of Herpetology 25:217–220. R Core Team. 2013. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. Available online at http://www.R-project. org/. Accessed 7 July 2013. Remsberg, A.J., T.L. Lewis, P.W. Huber, and K.A. Asmus. 2006. Home ranges of Wood Turtles (Glyptemys insculpta) in Northern Michigan. Chelonian Conservation and Biology 5:42–47. Ross, D.A., K.N. Brewster, R.K. Anderson, N. Ratner, and C.M. Brewster. 1991. Aspects of the ecology of Wood turtles, Clemmys insculpta, in Wisconsin. Canadian Field Naturalist 105:363–367. Sargent, B.D. 2014. Rare, threatened, and endangered animal species. West Virginia Department of Natural Resources, Charleston, WV. Saumure, R.A., and J.R. Bider. 1998. Impact of agricultural development on a population of Wood Turtles (Clemmys insculpta) in Southern Québec, Canada. Chelonian Conservation and Biology 3:37–45. Saumure, R.A., T.B. Herman, and R.D. Titman. 2007. Effects of haying and agricultural practices on a declining species: The North American Wood Turtle, Glyptemys insculpta. Biological Conservation 135:581–591. Tessier, N., S.R. Paquette, and F.-J. Lapointe. 2005. Conservation genetics of the Wood Turtle (Glyptemys insculpta) in Quebec, Canada. Canadian Journal of Zoology 83:765–772. Tuttle, S.E. 1996. Ecology and natural history of the Wood Turtle (Clemmys insculpta) in Southern New Hampshire. M.Sc. Thesis. Antioch University, Keene, NH. Northeastern Naturalist 402 J. Curtis and P. Vila 2015 Vol. 22, No. 2 Tuttle, S.E., and D.M. Carroll. 1997. Ecology and natural history of the Wood Turtle (Clemmys insculpta) in southern New Hampshire. Chelonian Conservation and Biology 2:447–449. US Census Bureau. 2012. 2010 Census of population and housing, population and housing unit counts, CPH-2-50, West Virginia. US Census Bureau, Washington, DC. Available online at http://www.census.gov/prod/cen2010/cph-2-50.pdf. Accessed 3 July 2013. US Geological Survey (USGS). 2010. National hydrography dataset (NHD - 24k). Available online at http://wvgis.wvu.edu/data/dataset.php?ID=235. Accessed 15 July 2013. Van Dijk, P.P., and J.H. Harding. 2011. Glyptemys insculpta (Wood Turtle). IUCN 2013. IUCN Red List of Threatened Species. Available online at http://www.iucnredlist.org/ details/summary/4965/0. Accessed 24 January 2014. Walde, A.D., J.R. Bider, C. Daigle, D. Masse, J.-C. Bourgeois, J. Jutras, and R.D. Titman. 2003. Ecological aspects of a Wood Turtle, Glyptemys insculpta, population at the northern limit of its range in Québec. The Canadian Field-Naturalist 117:377–388.