Efficacy of BioBlitz surveys with implications for sampling Nongame species.
Concerns about worldwide biodiversity declines have resulted in an upsurge of species inventory activities (Margules et al., 2002). In particular, significant population declines have been reported in amphibians, reptiles, and several small mammal species (e.g., Gibbons et al., 2000; Collins and Storfer, 2003; Stuart et at., 2004; LoGiudice, 2008). One inventory method that has rapidly gained popularity among scientists, resource managers, and educators since its conception in 1996 is the BioBlitz (Lundmark, 2003). BioBlitz surveys are short duration (generally < 3 d), intensive survey efforts where multiple experts and volunteers work together to identify as many species as possible (Karns et al., 2006). BioBlitzes are an attractive sampling approach because they yield quick estimates of species richness and composition, generally are cost efficient because volunteers are used, promote networking among professionals, and provide opportunities for public education (Lundmark, 2003; Karns et al., 2006). However, there is limited information on the effectiveness of BioBlitz surveys to detect species. Given their short duration, it is hypothesized that BioBlitzes are less effective at detecting species, particularly those that are rare or elusive, compared to more traditional survey methods that are conducted over longer durations (Karns et al., 2006). There is a need to compare species detection and effort expended during each survey type so that natural resource agencies can assess the usefulness of BioBlitzes for generating baseline species inventories.
Species detection may vary among sampling techniques. Although several studies have evaluated common capture methods for nongame species, such studies typically focus on limited taxa and methods (Ribeiro-Junior et al., 2008). Few studies have addressed the efficacy of common capture methods for estimating total species richness (rather than capture of individuals), and such investigations have never been undertaken for southern Appalachian herpetofaunal or small mammal prey species. Therefore, the objectives of our study were (1) to evaluate the efficacy of Bio Blitz surveys by comparing herpetofaunal and small non-volant mammal species detection and survey effort between a BioBlitz and a traditional survey and (2) to compare the ability of common sampling methods for herpetofaunal and small mammal communities to detect species richness.
Materials and methods
Our study was conducted on the Rocky Fork Unit of Cherokee Wildlife Management Area (hereafter: Rocky Fork) located in Unicoi and Greene counties, Tennessee. The sampling area was a 150 ha (0.5 km X 3 km) rectangular portion of Rocky Fork centered on a small pond (36.050567 [degrees],--82.570933'). The sampling area consisted primarily of forest dominated by yellow birch (Betula alleghaniensis), eastern hemlock (Tsuga canadensis), and tulip poplar (Liriodendron tulipifera) with interspersed early successional areas dominated by panic grass (Panicum sp.), violet (Viola sp.), and blackberry (Rubus sp.; M. Foster, University of Tennessee, unpubl. data). The sampling area included portions of Rocky Fork and Flint creeks, smaller tributaries, and several small seeps. The elevation range was 730-1100 m.
Herpetofaunal and small non-volant mammal species were recorded during a BioBlitz survey conducted with 22 observers on 20-22 June 2006, and a traditional survey that was conducted with two observers from May to November 2007. We assumed that species composition in the sampling area did not change between years. To prevent knowledge of species occurrence during the BioBlitz affecting species detection during the traditional surveys, the two traditional survey observers did not participate in the BioBlitz and results were not shared. Standard field guides were used to identify species. When species could not be positively identified using morphological characters alone (e.g., for dusky salamanders [Desmognathus spp.]), identification was based on reported geographic ranges for Tennessee (Redmond and Scott, 1996).
Herpetofaunal sampling--Visual encounter surveys were performed approximately 8 h per week from May to August and 8 h each month from September to November during the traditional survey. Each observer conducted 3-9 h of visual surveys daily during the BioBlitz. Searches were performed along 7 km of systematically placed transects that incorporated changes in creek order, elevation, canopy cover, and plant community type throughout the sampling area for both surveys. Observers during the traditional survey required several days to complete transects, whereas observers during the BioBlitz simultaneously searched different sections of transects, with some sections repeated daily. Observers looked for exposed animals and also overturned natural debris (e.g., logs, rocks; Dodd, 2009) in search of herpetofauna. Dip nets were also used during visual encounter surveys to capture amphibians in the pond and site tributaries.
Plywood (61 X 61 cm) and tin (61 x 122 cm) were used for artificial cover objects. A total of 80 cover objects were used during both surveys, although 50 wood and 30 tin cover objects were used during the traditional survey and 40 objects of each type were used during the BioBlitz survey. Cover objects were placed along transects and arrays (10 m spacing) systematically placed to incorporate changes in creek order, elevation, canopy cover, and plant community type throughout the sampling area. Cover objects were checked one or two times per week from May to August and one or two times each month from September to November during the traditional survey. Cover objects were checked once or twice daily during the BioBlitz. Cover objects were checked at a variety of times and ambient temperatures during both surveys.
Advertisement call surveys were conducted for anurans at a fixed point on the pond edge. Call surveys were conducted once per week from May to August and once per month from September to November during the traditional survey. Surveys were conducted according to the North American Amphibian Monitoring Program protocol at least 30 min after sunset for a period of 10 min (USGS Patuxent Wildlife Research Center, 2009).
Twelve 19-L pitfall traps were installed approximately 10 m apart along either side of a silt drift fence (0.9 m with 15 cm buried) that enclosed 50% of the pond. Amphibians can potentially crawl out of pitfall traps (Vogt and Hine 1982), so we fitted six of the twelve pitfall traps with 3.8 cm ledges constructed by cutting the center out of bucket lids and alternated them with unmodified pitfall traps to compare the efficacy of each trap design to retain trapped animals. We constructed a funnel box trap following the general design of Rudolph et al. (1999) and placed it 40 m east of the pond. The box trap had four 30-m silt fence leads (0.9 m with 15 cm buried) that extended perpendicular from each side of the box at wire mesh funnel entrances. Fourteen smaller funnel traps were constructed following Corn (1994). Eight were placed along the opposite end of the drift fence leads from the box trap, and six funnel traps were placed systematically along natural corridors (e.g., downed logs and large rocks) in terrestrial and aquatic environments during the traditional survey. Traps were partially covered with vegetation to camouflage traps and to prevent captured animals from overheating. Both 19-L pitfall and funnel traps were opened 4 consecutive days per week from May to August and 4 consecutive days per month from September to November during the traditional survey, and checked each morning.
Small mammal sampling--A combination of Sherman live traps (H. B. Sherman Traps, Tallahassee, Florida, USA) and 0.6-L pitfall traps were used during both surveys to inventory small mammal prey species. We placed 160 Sherman traps baited with assorted grains rolled in peanut butter during the BioBlitz and 180 traps during the traditional survey along transects in pairs 5 m apart. Traps were opened and checked within 2 h of sunrise for 4 consecutive days per month from May to August during the traditional survey and each day during the BioBlitz.
Pitfall traps (0.6-L) were placed in pairs along natural corridors (e.g., downed logs) equally dispersed throughout the sampling area to target species (e.g., shrews) that are unlikely to be captured in Sherman live traps (Fabiana et al., 2006). Twenty pitfall traps were installed during the BioBlitz and checked at least once daily. For the traditional survey, 25 pitfall traps were opened for 4 consecutive days per month from May to August, and checked once per day.
Statistical analyses--We estimated species richness of the sampling area using capture data from the traditional survey and the Chao2 estimator in EstimateS (Colwell, 2004). The Chao2 estimator used histories of species detection from each sampling period of the traditional survey to estimate species richness. We also estimated species richness data from the traditional survey for each sampling technique to identify which techniques were most effective at species detection. We qualitatively compared species lists generated during the traditional and BioBlitz surveys to the Chao2 species richness estimates for a measure of efficacy of the BioBlitz survey at detecting species. These estimates also were compared with known species lists compiled from both surveys. We calculated catch per unit effort (CPUE) for each capture method and species for the traditional survey. Due to the hectic nature of BioBlitz surveys, captures of individual animals were not recorded and therefore CPUE could not be calculated for the BioBlitz. Lastly, sampling effort for each method and total sampling effort (expressed as person-hours) spent during both surveys was reported.
The Chao2 estimate for salamander species richness was 15 (SD = 2.2), and a total of 15 species were detected between both surveys (Table 1). Two species (Northern Gray-Cheeked Salamander [Plethodon montanus] and Red Salamander [Pseudo triton ruber]) were detected only during the traditional survey and one species (Eastern Hellbender [Cryptobranchus alleguniensis] was unique to the BioBlitz survey. For anurans, the Chao2 estimate was eight species (SD = 2.2), and eight species were recorded between both surveys. Five anuran species were detected only by the traditional survey and one species (Fowler's Toad [Anaxyrus fowleri]) was recorded solely during the Bio Blitz. For snakes, the Chao2 estimate was six species (SD = 0.01), which was the number of species detected with both surveys. One of these (Eastern Milk Snake [Lampropeltus triangulum]) was unique to the traditional survey. Finally, Chao2 predicted that 12.5 (SD = 1.2) small mammal species occur in the sampling area; a total of 14 species were detected during both surveys. Four small mammal species were detected only during the traditional survey, and three species were detected solely during the BioBlitz (Table 2).
The Chao2 estimate of salamander species richness and CPUE was higher for visual encounter surveys than other sampling methods (Table 1, Fig. 1 a). Data from both pitfall types (ledges and no ledges) were pooled to improve sample size for Chao2 analyses. However, the majority (85%) of salamanders detected in pitfall traps were captured in traps with ledges. For anurans, the greatest number of species was detected using funnel traps and call surveys (Fig. 1 b). Anuran CPUE was greatest for pitfall traps (Table 1); however, only a single age class, of a single species (metamorphic Green Frogs [Lithobates clamatans]) was detected using pitfall traps. Chao2 estimates of snake species richness as well as CPUE were higher for tin cover objects than other sampling methods (Fig 1c). Finally, Chao2 estimates and CPUE for small mammals were higher for Sherman live traps than 0.6-L pitfall traps (Table 2; Fig. 1d).
TABLE 1. Detection of salamander, anuran and snake species (Y = detected, N = not detected) during a BioBlitz survey (20-22 June 2006; 22 observers) and a traditional survey conducted for longer duration with two observers (May-November 2007) on the Rocky Fork Unit, Cherokee Wildlife Management Area, Greene and Unicoi counties, Tennessee. Catch per unit effort (CPUE; animals caught per pitfall trap night, funnel trap night, wood cover object flip, tin cover object flip, and hour of visual encounter search) is presented for the traditional survey. Survey CPUE Pitfall Pitfall Species BioBlitz Traditional (19 L. (19 L, Funnel Wood ledge) no ledge) Cryptohranchus Y N 0.000 0.000 0,000 0.000 alleganiensis Desmognathus Y Y 0.079 0.016 0.006 0.005 carolinensis Desmognathus Y Y 0.000 0.000 0.000 0.000 fuscus Desmognathus Y Y 0.000 0.000 0.001 0.000 marmoratus Desmognathus N Y 0.032 0.012 0.003 0.004 monticola Desmognathus Y Y 0.012 0.000 0.000 0.001 quadramaculatus Eurycea Y Y 0.111 0.012 0.016 0.006 wilderae Gyrinophiius Y Y 0.000 0.000 0.000 0.000 porphyriticus Notophthalmus Y Y 0.000 0.000 0.018 0.000 viridescens Plethodon Y Y 0.000 0.004 0.000 0.000 cinereus Plethodon mon Y Y 0.000 0.000 0.000 0.001 tanus Plethodon Y Y 0.000 0.000 0.001 0.020 cylindraceus Plethodon Y Y 0.000 0.000 0.000 0.000 ventralis Plethodon Y Y 0.004 0.000 0.000 0.000 yonahlossee Pseudotriton N Y 0.024 0.000 0.004 0.000 ruber Total 13 14 0.261 0.043 0.051 0.037 salamanders Anaxyrus Y Y 0.000 0.000 0.001 0.000 americanus Anaxyrus Y N 0.000 0.000 0.000 0.000 fowleri Hyla N Y 0.000 0.000 0.000 0.000 chrysoscelis Lithobates N Y 0.000 0.000 0.015 0.000 catesbeumus Lithohates Y Y 0.103 0.071 0.033 0.000 c/amitans Lithobates N Y 0.000 0.000 0.009 0.000 pahistris Lithobates N Y 0.000 0.000 0.007 0.000 sylvaticus Pseudaeris N Y 0.000 0.000 0.000 0.000 crucifer Total anurans 3 7 0.103 0.071 0.065 0.000 Agkistrodon Y Y 0.000 0.000 0.004 0.000 contortrix Diadophis Y Y 0.004 0.000 0.003 0.011 punctatus Lampropeltis N Y 0.000 0.000 0.000 0.000 triangulum Pantherophis Y Y 0.000 0.000 0.000 0.000 alleghaniensis Nerodia sipedon Y Y 0.000 0.000 0.001 0.000 Thamnophis Y Y 0.000 0.000 0.012 0.005 sirtalis Total snakes 5 6 0.004 0.000 0.021 0.016 Tin VES 0.000 0.000 0.000 0.375 0.000 0.021 0.000 0.007 0.000 0.208 0.000 0.090 0.000 0.090 0.000 0.021 0.000 0.028 0.000 0.021 0.000 0.042 0.000 0.146 0.000 0.028 0.000 0.021 0.000 0.007 o.ooo 1.104 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.007 0.000 0.007 0.000 0.000 0.000 0.000 0.000 0.014 0.000 0.028 0.002 0.004 0.011 0.003 0.001 0.000 0.000 0.001 0.012 0.000 0.052 0.000 0.077 0.009 TABLE 2. Detection of small mammal species (Y = detected, N = not detected) during a BioBlitz survey (20-22 June 2006; 22 observers) and a traditional survey conducted for longer duration with two observers (May-November 2007) on the Rocky Fork Unit, Cherokee Wildlife Management Area, Greene and Unicoi counties, Tennessee. Catch per unit effort (CPUE; animals caught per pitfall trap night, Sherman trap night, funnel trap night, and hour of visual encounter search) is presented for the traditional survey. Survey CPUE Pitfall Species BioBlitz Traditional (0.6 Sherman Funnel VES L) Blarina Y Y 0.007 0.004 0.000 0.000 brevicauda Myodes N Y 0.000 0.002 0.001 0.000 gapperi Condylura Y N 0.000 0.000 0.000 0.000 cristata Microtus Y N 0.000 0.000 0.000 0.000 pinetorum Napaeozapus Y Y 0.000 0.019 0.007 0.000 insignis Ockrotomys Y Y 0.000 0.006 0.000 0.000 nuttalli Peromyscus Y Y 0.000 0.000 0.000 0.001 leucopus Peromyscus Y Y 0.003 0.021 0.000 0.000 maniculatus Sigmodon N Y 0.000 0.001 0.000 0.000 hispidus Sorex hoyi Y N 0.000 0.000 0.000 0.000 Sorex N Y 0.007 0.000 0.000 0.000 longirostris Sorex Y Y 0.003 0.001 0.000 0.000 cinereus Sorex fumeus Y Y 0.027 0.000 0.000 0.000 Tamias N Y 0.000 0.002 0.001 0.001 striatus Total small 10 11 0.047 0.057 0.010 0.002 mammals
Nearly 1200 total 19-L pitfall and funnel trap-nights were accrued during the traditional survey (Table 3), whereas 19-L pitfall and funnel traps were not used during the BioBlitz. Fifteen anuran call surveys were conducted during the traditional survey, but none during the BioBlitz. Wood and tin cover objects were flipped nearly 1700 times during the traditional survey but only 360 times during the BioBlitz. Nearly 2500 Sherman and 0.6-L pitfall trap-nights were accrued during the traditional survey, but only 540 during the BioBlitz. Visual search effort during the traditional survey (144 h) was nearly twice the BioBlitz (84 h). Total person-hours recorded were approximately 160 for the BioBlitz and 650 for the traditional survey (Table 3).
TABLE 3. Survey effort expended during a BioBlitz survey (20-22 June 2006, 22 observers) and a traditional survey (May--November 2007, two observers) on the Rocky Fork Unit, Cherokee Wildlife Management Area, Greene and Unicoi counties, Tennessee. Survey type Detection method Bio Blitz Traditional Pitfall trap nights (19 L)(1),(2) 0 506 Funnel trap nights (1) 0 672 Tin cover object flips (3) 240 650 Wood cover object flips (3) 120 1030 Anuran call surveys 0 15 Visual encounter search hours 84 144 Sherman trap nights (1) 480 2160 Pitfall trap nights (0.6 L) (1),(4) 60 300 Total person-hours 160 650 (1.) Total trap nights are equal to the number of traps multiplied by the number of nights traps were active. (2.) 19-L pitfall traps were installed along drift fence. (3.) Total flips are equal to the number of cover objects multiplied by the number of times the objects were lifted in search of animals. (4.) 0.6-L pitfall traps were installed along natural debris (e.g., logs, rocks).
The BioBlitz and traditional surveys independently documented 71-100% of salamander, snake, and small mammal species known from the sampling area (i.e., the combined species list from both surveys). For anurans, the traditional survey detected 88% of known species, whereas the BioBlitz detected only 34% of the species. Salamander species richness was best sampled during visual encounter surveys, anurans using call surveys, snakes under tin cover boards, and small mammals in Sherman traps. The amount of effort differed substantially between survey types. Total personhours expended during the traditional survey (650) were four
times greater than during the BioBlitz (160).
Species lists generated during traditional and BioBlitz surveys were similar for salamanders, with 12 of 15 salamander species known from the study area detected during both surveys. Salamander species were best detected during visual encounter surveys than any other survey method. Therefore, similarity between species lists for salamanders likely resulted from substantial effort allocated to visual encounter surveys during both the BioBlitz (84 h) and traditional (144 h) surveys.
Conversely, species lists for anurans were not similar between surveys. Seven of eight anuran species known from the study area were recorded during the traditional survey whereas only three anuran species were detected during the BioBlitz. Similarly, Karns et al. (2006) recorded only two anuran species during a BioBlitz in Indiana. Anurans are most detectible during the breeding season when males vocalize and activity increases, but breeding seasons are not concurrent among species (Dodd, 2004). Hence, not all members of the anuran community may be detectible at any time, and shortduration BioBlitz surveys cannot be expected to yield a complete species list for anurans.
None of the capture methods employed during the traditional survey effectively detected anuran species richness. Catch per unit effort was greatest for pitfall traps, but only metamorphic green frogs were detected by pitfalls, illustrating the importance of employing a wide variety of detection methods when the goal of a survey is to inventory species richness.
Call surveys are superior to capture efforts for anuran species inventory (Fig. Ib; Gunzburger, 2007). We detected five of seven species recorded during the traditional survey during call surveys, but did not hear Wood Frogs (Lithobates sylvaticus) or American Toads (Anaxyrus americanus) because they typically breed early (February--April; Dodd, 2004), and we began the traditional survey in May. However, both species are known to call in the sampling area (M. Foster, University of Tennessee, unpubl. data). In addition to good detection, anuran call surveys are cost-effective to conduct. The North American Amphibian Monitoring Program (NAAMP) suggests 10-min surveys conducted four times annually (USGS Patuxent Wildlife Research Center, 2009). Thus, if anurans are of interest, we recommend seasonal call surveys be conducted to supplement BioBlitz data.
Similar to results for salamanders, five and six of six snake species were recorded from the sampling area during the BioBlitz and traditional surveys, respectively. Snake species richness and CPUE were greatest for tin cover objects compared to other survey methods. Others have reported tin is more effective than wood cover objects for surveying reptiles because it heats up quickly, but previous studies did not compare the efficacy of cover objects to other common sampling methods (Grant et al., 1992; Engelstoft and Ovaska, 2000; Hampton, 2007). Tin cover objects were used during both surveys, but were in place for longer duration and flipped more total times during the traditional survey than the BioBlitz. Detection of one additional species (Eastern Milk Snake) during the traditional survey may have resulted from this increased effort.
Species lists also were similar for small mammal species, with at least 10 of 14 known species recorded independently during the BioBlitz and traditional surveys. Small mammals were better detected using Sherman live traps than using 0.6-L pitfall traps, but estimates of species richness for the two methods combined were more accurate and precise than estimates generated using data from Sherman live traps alone. This is because some species (e.g., shrews) are more detectible in pitfall than Sherman live traps (Fabiana et al., 2006; Sedivec et al., 2006). Sherman live traps and 0.6 L pitfall traps were used during both the traditional and BioBlitz surveys; hence species detection was similar between surveys.
Both BioBlitz and traditional surveys were effective for inventorying salamander, snake, and small mammals species, but neither survey detected every species known from the sampling area. Differences in species detection between surveys may have resulted from differing capture methods. For example, Red Salamanders were detected mostly (90%) in 19-L pitfall and funnel traps installed along drift fence during the traditional survey (Table 1). Red Salamanders were not detected during the Bio Blitz, possibly because the labor associated with installation of drift fence was not warranted for the short-duration BioBlitz; hence this capture method was not used. Differences in detection between the traditional and BioBlitz surveys may also have resulted from differences in sampling intensity or duration, experience of observers, and seasonal species activity or weather (Karns et al., 2006). The traditional survey occurred during a drought year (National Climactic Data Center, 2008), which might have improved detectibility of some species (e.g., if species are concentrated at water sources) but may have reduced detectibility of others. Finally, chance probably affects detection of locally rare or elusive species. Of the 11 salamander, snake, and small mammal species that went undetected in one of the two surveys, nine were represented by fewer than five capture events.
Slight differences in detection of locally rare or elusive species between surveys suggest there are advantages and disadvantages to each survey type. Observers hired to conduct traditional surveys are generally better trained than volunteers conducting BioBlitz surveys. It is also easier to standardize methodologies and data collection among fewer observers during traditional surveys. BioBlitz surveys can utilize experts in a field (e.g., herpetologists skilled at salamander identification) who would not have time to participate in traditional survey efforts. Thus, a combination of BioBlitz and traditional surveys would be expected to yield a more complete species list than either survey method alone.
For situations where funding and interest .allow for areas to be surveyed in multiple years, we recommend a combination of BioBlitz and traditional surveys be employed. However, BioBlitz surveys may be more practical for wildlife managers because they are time-effective, cost-effective, and an excellent method for involving and engaging the public. When BioBlitz surveys will be conducted in multiple years, we recommend they occur at different times of the year to minimize the effects of temporal differences on species detection. We also recommend wildlife managers and researchers design Bioblitz surveys with several sample occasions (e.g., days of a BioBlitz survey) where the entire study area is surveyed and all individual animals detected are recorded. This would allow for the calculation of species detection probabilities (e.g., using occupancy models; MacKenzie et al., 2006) and use of rarefaction to estimate species richness (e.g., Chao2; Colwell, 2004). However, survey leaders should be aware that rarefaction based species richness estimators may be biased by incomplete species detection (e.g., if a species is not detected due to the timing or methodologies employed during the survey) and therefore can potentially underestimate species richness (Cam et al., 2002).
Our results suggest BioBlitzes are effective for providing baseline information on salamander, snake, and small mammal communities, but are ineffective for anuran detection. We recommend BioBlitzes be supplemented with anuran call surveys throughout the year. The total effort expended during the BioBlitz (160 person-hours) was four times less than that expended during the traditional survey (650 person-hours). Although BioBlitzes vary widely in the number and experience of observers, survey duration, size, and habitat (Karns et al., 2006), our research suggests BioBlitz surveys have the potential to yield quality data at relatively low effort and cost, particularly if volunteer labor is used.
The University of Tennessee Institute of Agriculture provided funding. We are grateful to the Tennessee Wildlife Resources Agency (TWRA), especially D. Lane, for providing field housing. All sampling activities were approved under TWRA Scientific Collection Permit #1990 and the University of Tennessee Institutional Animal Care and Use Committee (#1653-0807). We thank E. Groseclose, J. Mulhouse, J. Ripley, and numerous volunteers for help during field sampling.
Cam, E., J. D. Nichols, J. E. Hines, J. R. Sauer, R. Alpizar-Jara, and C. H. Flather. 2002. Disentangling sampling and ecological explanations underlying species-area relationships. Ecology, 83:1118-1130.
Collins, J. P., and A. Storfer. 2003. Global amphibian declines: sorting the hypotheses. Diversity and Distributions, 9: 89-98.
Colwell, R. K. 2004. EstimateS: Statistical estimation of species richness and shared species from samples. University of Connecticut, Storrs. Available from http://purl.ocic. org/estimates.
Corn, P. S. 1994. Straight-line drift fences and pitfall traps. Pp. 109-117 in Measuring and monitoring biological diversity: standard methods for amphibians (W. R. Heyer, M. A. Donnelly, R. W. McDiarmid, L. C. Hayek, and M. S. Foster, eds.). Smithsonian Institution Press, Washington D.C.
Dodd, C. K. Jr. 2004. The amphibians of Great Smoky Mountains National Park. University of Tennessee Press, Knoxville.
Dodd, C. K. Jr. 2009. Amphibian ecology and conservation: a handbook of techniques. Oxford University Press, Oxfordshire, United Kingdom.
Engelstoft, C., and K. E. Ovaska. 2000. Artificial cover-objects as a method for sampling snakes (Contia tenuis and Thamnophis spp.) in British Columbia. Northwestern Naturalist, 81:35-43.
Fabiana, U., L. Naxara, and R. Pardini. 2006. Evaluating the efficiency of pitfall traps for sampling small mammals in the neotropics. Journal of Mammology, 87:757-765.
Gibbons, J. W., D. E. Scott, T. J. Ryan, K. A. Buhlmann, T. D. Tuberville, B. S. Metts, J. L. Greene, T. Mills, Y. A. Leiden, S. Poppy, and C. T. Winne. 2000. The global decline of reptiles, OA vu amphibians. Bioscience, 50:653-666.
Grant, B. R., A. D. Tucker, J. E. Lovich, A. M. Mills, P. M. Dixon, and J. W. Gibbons. 1992. The use of cover boards in estimating patterns of reptile and amphibian diversity. Pp. 379-403 in Wildlife 2001: populations (D. R. McCullough, and R. H. Barrett, eds.). Elsevier Publishing, New York, New York.
Gunzburger, M. S. 2007. Evaluation of seven aquatic sampling methods for amphibians and other aquatic fauna. Applied Herpetology, 4:47-63.
Hampton, P. 2007. A comparison of the success of artificial cover types for capturing amphibians and reptiles. Amphibia-Reptilia, 28:433-437.
Karns, D. R., D. G. Ruche, R. D. Brodman, M. T. Jackson, P. E. Rothrock, P. E. Scott, T. P. Simon, and J. 0. Whitaker, Jr. 2006. Results of a short-term BioBlitz of the aquatic and terrestrial habitats of Otter Creek, Vigo County, Indiana. Proceedings of the Indiana Academy of Science, 115:82-88.
LoGiudice, K. 2008. Multiple causes of the Allegheny woodrat decline: a historical-ecological examination. Pp. 23-43 in The Allegheny woodrat: ecology conservation and management of a declining species (Peles, J. D., and J. Wright, eds.). Springer, New York, New York.
Lundmark, C. 2003. BioBlitz: getting into backyard biodiversity. Bioscience, 53:329.
MacKenzie, D. I., J. D. Nichols, J. A. Royle, K. H. Pollock, L. L. Bailey, and J. E. Hines. 2006. Occupancy estimation and modeling: inferring patterns and dynamics of species occurrence. Academic Press, New York, New York.
Margules, C. R., R. L. Pressey, and P. H. Williams. 2002. Representing biodiversity: data and procedures for identifying priority areas for conservation. Journal of Bioscience, 27:309-326.
National Climactic Data Center. 2008. Climate of 2007 annual review: U.S. drought. Available from http://www.ncdc. noaa.gov/oa/climate/research/2007/ann/drought-summary. html
Redmond, W. H., and A. F. Scott. 1996. Atlas of amphibians in Tennessee. Austin Peay State University, Clarksville, Tennessee. Available from http://www.apsu.edu/~aniatlas/
Ribeiro-Junior, M. A., T. A. Gardner, and T. C. Avila-Pires. 2008. Evaluating the effectiveness of herpetofaunal sampling techniques across a gradient of habitat change in a tropical forest landscape. Journal of Herpetology, 42:733-749.
Rudolph, C., S. Burgdorf, R. Conner, and R. Schaefer. 1999. Preliminary evaluation of the impact of roads and associated vehicular traffic on snake populations in eastern Texas. Pp. 129-136 in Proceedings of the third international conference on wildlife ecology and transportation (G. L. Evink, P. Garrett, and D. Ziegler, eds.). Florida Department of Transportation, Tallahassee.
Sedivec, S. A., S. P. Niedzwiecki, and H. P. Whidden. 2006. Relative trap effectiveness and the implications for inventories of small mammals. Journal of the Pennsylvania Academy of Science, 79:123-124.
Stuart, S. N., J. S. Chanson, N. A. Cox, B. E. Young, A. S. L. Rodrigues, D. L. Fischman, and R. W. Wailer. 2004. Status and trends of amphibian declines and extinctions worldwide. Science, 306:1783-1785.
United States Geological Survey Patuxent Wildlife Research Center. 2009. North American Amphibian Monitoring Program: protocol description. Patuxent, Maryland. Available from http://www.pwrc.usgs.gov/naamp/index. cfm?fuseaction=app.protocol
Vogt, R. C., and R. L. Hine. 1982. Evaluation of techniques for assessment of amphibian and reptile populations in Wisconsin. Pp. 201-217 in Herpetological Communities (N. J. Scott, Jr., ed.). U.S. Department of the Interior, Fish and Wildlife Service, Wildlife Research Report 13.
Submitted 27 January 2012; accepted 26 August 2013.
Melissa A. Foster*, Lisa I. Muller, Scott A. Dykes, R. L. Pete Wyatt, and Matthew J. Gray
274 Ellington Plant Sciences Building, Department of Forestry, Wildlife and Fisheries, University of Tennessee, Knoxville, TN 37996, USA (MAF, LIM, MJG)
Tennessee Wildlife Resources Agency, 3030 Wildlife Way Morristown, TN 37814 (SAD, RLPW)
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|Author:||Foster, Melissa A.; Muller, Lisa I.; Dykes, Scott A.; Wyatt, R. L. Pete; Gray, Matthew J.|
|Publication:||Journal of the Tennessee Academy of Science|
|Date:||Sep 1, 2013|
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