Four-toed salamanders Hemidactylium scutatum have disjunct populations in the United States and Canada. Increased predation could threaten their populations and cause them to become limited in certain areas. Installing cages to protect threatened populations can reduce the chance of predation. To test the efficacy of cages, we examined the effects of caging four-toed salamander nests in northeastern Tennessee. We randomly selected 65/120 nests to cage from our study sites at the South Holston Weir Dam and Bouton Tract in Sullivan County, Tennessee. Based on photos from a camera trapping survey, we found that raccoons Procyon lotor were the main predators of uncaged four-toed salamander nests. Raccoon damage resulted in portions of moss being ripped away and the disappearance of eggs. Twenty-six percent of uncaged nests were preyed upon, whereas none of the caged nests were preyed upon. Our findings provide a strategy for improving nest success of four-toed salamanders and could be used to protect threatened populations.

Nest cages are an effective alternative conservation tool to lethal control that can be used to protect vulnerable individuals, such as nesting females and embryos, without ethical or negative public opinions. There are many techniques that can be used to successfully reduce predation; however, the key is to separate individuals from the threat (Somers and Hayward 2012). The effectiveness of nest cages has been observed globally, mainly in ground-nesting birds and turtles. Ringma et al. (2020) found that predator nest cages significantly increased the survival rate of over 30 bird species in New Zealand. Loggerhead Caretta caretta and green sea turtle Chelonia mydas nests surrounded by cages experienced less nest predation than unprotected nests (Baskale and Kaska 2005).

There has been limited work on the potential of nest cages to benefit amphibians by reducing nest predation. Croshaw and Scott (2005) conducted an experiment to observe if predator exclusion would reduce egg mortality of marbled salamanders Ambystoma opacum nests. The authors placed 25 cm × 51 cm (9.8 in × 20 in) aluminum cylinders around the nests of females and found significantly higher hatching rates in protected than unprotected nests. This study was successful in demonstrating how one amphibian species is positively impacted by nest cages and showcases the potential of protecting additional salamander species.

Four-toed salamanders Hemidactylium scutatum (Figure 1) has the widest range of all plethodontid species, and their disjunct populations start on the eastern edge of the Atlantic Ocean and extend from Nova Scotia to Florida and continue westward to Oklahoma and Missouri (Herman and Bouzat 2016). Four-toed salamanders live in hardwood forests with dense canopies covering vernal pools, swamps, and bogs. Their nesting ecology is uncommon for plethodontid salamanders and increases concerns about their ability to persist on the landscape. After mating, female four-toed salamanders leave upland forests and migrate to wetlands from late fall to early spring to deposit their eggs. Four-toed salamanders typically nest in moss clumps of the genera Thuidium, Mnium, Sphagnum, Climacium, Atrichum, Aulatcomnium, Cirriphyllum, Entodon, Eurhynchium, Hypnum, Leptodictyum, Leucobryum, or Plagiothecium above the waterline around pools and sluggish streams (Gilbert 1941; Wood 1955; Chalmers and Loftin 2006; Wahl et al. 2008; Figure 2). Females also infrequently deposit eggs under coarse woody debris, vegetation, and leaf litter (Petranka 1998). Females can lay eggs independently or jointly with other female four-toed salamanders in the same moss clump (Blanchard 1934). Depositing eggs takes between 12–72 hours, which makes it essential for the female not to be disturbed and creates a window of potential predation of the female and her eggs (Petranka 1998).

Figure 1.

Female four-toed Salamander Hemidactylium scutatum at South Holston Weir Dam in Sullivan County, Tennessee in April 2022. Photo Credit: Charlie Holguin.

Figure 1.

Female four-toed Salamander Hemidactylium scutatum at South Holston Weir Dam in Sullivan County, Tennessee in April 2022. Photo Credit: Charlie Holguin.

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Figure 2.

Female four-toed salamander Hemidactylium scutatum guarding her eggs within a clump of moss in April 2022 at South Holston Weir Dam in Sullivan County, Tennessee.

Figure 2.

Female four-toed salamander Hemidactylium scutatum guarding her eggs within a clump of moss in April 2022 at South Holston Weir Dam in Sullivan County, Tennessee.

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Throughout most of their range, four-toed salamander populations appear to be declining, as 17 of the 29 states they inhabit have designated some level of conservation status and protection for the species (Table 1). These salamanders are most vulnerable during their nesting season due to habitat loss and clustering of the salamanders in vernal pools and ditches (Petranka 1998; Mitchell and Gibbons 2010). While habitat loss is assumed to be the leading conservation concern (Petranka 1998; Mitchell and Gibbons 2010), nest predation also appears to be a neglected source of mortality and nest failure (Herman 2013). Due to their guarding behavior, female four-toed salamanders are vulnerable to predation during the nesting season (Carrenó and Harris 1998). Female salamanders can self-autotomize their tails, leaving a sharp bone fragment when attacked by small predators (e.g., ring-necked snake Diadophis punctatus; Herman 2013). However, tail loss provides little distraction to mesocarnivores attempting to prey on a nest, and nests are often preyed upon if located by mesocarnivores (Herman 2013). The aftermath of nest predation is often a destroyed nest with moss ripped from the substrate, eggs lost, and an absent female.

Table 1.

State conservation status ranks of four-toed salamanders Hemidactylium scutatum within the United States from state wildlife action plans, 2013–2019. The states are listed alphabetically, along with the designation given by each state wildlife action plan.

State conservation status ranks of four-toed salamanders Hemidactylium scutatum within the United States from state wildlife action plans, 2013–2019. The states are listed alphabetically, along with the designation given by each state wildlife action plan.
State conservation status ranks of four-toed salamanders Hemidactylium scutatum within the United States from state wildlife action plans, 2013–2019. The states are listed alphabetically, along with the designation given by each state wildlife action plan.

Nest predation has been documented in Ohio, Illinois, and Tennessee (Herman 2013; this study). In the case of joint nests, one predation event could remove the reproductive impact of many females (Wood 1955). Larvae often experience little predation due to the extremely small wetland areas they inhabit. However, larvae of Ambystoma can prey upon four-toed larvae (Mitchell and Gibbons 2010). Thus, most reproductive failures due to predation have been attributed to the nesting stage. The goal of our study is to determine if nest cages are successful in protecting female four-toed salamanders and their eggs during the nesting season. With this goal in mind, our objectives were to 1) identify nest predators of female four-toed salamanders and 2) determine if nest cages could reduce predation of four-toed salamander nests.

Site description

Our study sites are located on Tennessee Valley Authority properties in Northeast Tennessee (Sullivan County, Tennessee; Figure 3). The first study site is at the South Holston Weir Dam, where we observed four-toed salamanders nesting in a powerline right-of-way (ROW) and an adjacent forested tract across from the Osceola Island Recreation Area, on the east side of the South Holston River, with elevations ranging from 458 to 465 m. Osceola Island Recreation Area is a park environment with picnic tables, recreational space, and fishing access. Our second site is the Bouton Tract, which is located on the west side of the South Holston River and also has a ROW bisecting a forested tract with elevations ranging from 448 to 456 m.

Figure 3.

Aerial imagery of four-toed salamander Hemidactylium scutatum study sites used to investigate the efficacy of nest cages to reduce predation in Sullivan County, Tennessee in 2022. Study sites are indicated by red rectangles.

Figure 3.

Aerial imagery of four-toed salamander Hemidactylium scutatum study sites used to investigate the efficacy of nest cages to reduce predation in Sullivan County, Tennessee in 2022. Study sites are indicated by red rectangles.

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The forest canopy at the Weir Dam site is dominated by sweetgum Liquidambar styraciflua, red maple Acer rubrum, and sycamore Platanus occidentalis. Green ash Fraxinus pennsylvanica had previously comprised a large percentage of the canopy, but due to Emerald Ash Borer Agrilus planipennis, all green ash has died, leaving canopy gaps. American tree moss Climacium americanum dominates the edge of shallow pools in the ROW and forested areas, providing salamander nesting areas. At the Bouton Tract, the canopy is composed mainly of sweetgum, red maple, sycamore, and white oak Quercus alba. Shallow pools in the forested areas are lined with American tree moss, but pools in the ROW and edge are predominately bordered with Sphagnum sp.

Each site has ROWs distributing electricity generated from the hydroelectric facility at South Holston Dam. The ROWs are maintained predominantly with mechanical mowing on a three-to-five year cycle. The forest tract at the Weir Dam is maintained in a natural state with limited anthropogenic interactions, whereas the Bouton Tract has trails for hiking and fishing access to the South Holston River. We first observed four-toed salamanders nesting at the Weir Dam location in 2002 (Hamed and Gentry 2003) and in 2019 at the Bouton Tract.

Camera trapping survey

To determine the species preying upon four-toed salamander nests, we monitored nests from 2016 to 2019 by installing Recoynx (Holmen, WI) XR6 trail cameras approximately 3–5 m in front of clusters of four-toed salamander nests at the Weir Dam site. We placed cameras in areas that have previously experienced predation at forested and ROW edge areas. In 2016, we set one camera on a forest nest area where we could observe five total nests and two cameras on nests in the ROW that allowed us to observe seven total nests for a total of 93 camera days. In 2017, we placed two cameras in front of nests in forested areas (nine total nests) for 91 camera days. We defined a camera day as a 24-hour period where cameras were operating. We set cameras to record motion for 30-second intervals. To determine if and when predation occurred, we walked nests weekly and noted the approximate date of nest predation. At the end of each nesting season, we reviewed all videos and recorded the dates of each species' observation and activities (e.g., digging and scratching in moss) that would indicate nest destruction and predation. We confirmed if the nest had been preyed upon during the time period when the damaging activities were recorded. If individuals of the same species were photographed within 30 minutes of their first observation, we considered the observation to be the same individual and only scored it as a single observation (Kelly and Holub 2008).

Nest caging pilot study

In 2018, we randomly chose six nesting areas by using a table of random numbers (Heyer et al. 1994) and placed cages around 10 nests for a pilot study to examine the potential benefits of caging to reduce predation at the Weir Dam site. For each chosen nest, we used green PVC-coated steel wire fencing with 5.1 cm × 7.6 cm (2 × 3 in) mesh that was 61 cm (2 ft) in height (Blue Hawk; L.G. Sourcing, Inc., North Wilkesboro, NC). We supported the caging with three to four wooden stakes (5.1 × 5.1 × 61 cm) arranged in a triangular or rectangular shape, depending on natural objects, such as trees or logs, that could prevent the fencing from touching the ground (Figure 4). Since salamander larvae would be exposed to stakes, we used untreated wood. We attached fencing to the stakes with 0.64 cm (0.25 in) metal staples and ensured that the distance between the cage and the moss clump containing the nest was at least 5 cm (1.97 in).

Figure 4.

Cage surrounding four-toed salamander Hemidactylium scutatum nest used during multiple years (different colored flagging) at South Holston Weir Dam in Sullivan County, Tennessee during April 2022.

Figure 4.

Cage surrounding four-toed salamander Hemidactylium scutatum nest used during multiple years (different colored flagging) at South Holston Weir Dam in Sullivan County, Tennessee during April 2022.

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We randomly chose an area using a table of random numbers (Heyer et al. 1994) where two cameras could monitor eight caged nests and another area where seven uncaged nests could be monitored with two cameras. Additionally, we picked a fifth site where both caged (n = 2) and uncaged (n = 2) nests could be monitored with the same camera. Thus, we placed five cameras to monitor a total of 19 nests (9 uncaged and 10 caged). At each nesting cluster, we placed a Recoynx XR6 trail camera to observe the effectiveness of nest caging and followed the same methods used to initially identify nest predators. In 2019, we caged eight additional nests and placed cameras to observe two caged nesting areas (n = 10 total nests) and two uncaged (n = 11 total nests) areas. We quantified the number of potential predators visiting the nests and whether predation had occurred using the same methods in 2018.

Nest caging experiment

Based on the results from our nest caging pilot study (2018–2019), we expanded the project during the 2022 nesting season and included the Bouton Tract. We searched for four-toed salamander nests from 8 April 2022 to 8 May 2022 and located 160 at the South Holston Weir Dam site and 25 on the Bouton Tract. We located 25–40 nests on each sampling day and randomly chose a subset of 8–10 nests each day for caging using a table of random numbers (Heyer et al. 1994). We selected 59 nests at the Weir Dam and six nests at the Bouton Tract for caging. The remaining nests were left uncaged; thus, we caged 65 total nests and left 120 uncaged. We utilized the same methods to cage nests as our pilot study, except the green PVC-coated steel wire fencing was sourced from a different manufacturer (Garden Craft, Origin Point Brands, Summerville, SC). Instead of staples, we attached fencing to the stakes using nylon zip ties. To eliminate female abandonment, we did not do daily nest checks. However, on 19 May 2022 and 22 May 2022, we revisited each nest (both caged and uncaged) and determined if the nest had been preyed upon. Since 2007, we have observed four-toed salamanders hatching on or a few days before 15 May; therefore, we visited immediately after hatching. We deemed a nest preyed upon if the moss had been ripped and removed from the surface where it was growing and if there was no presence of the hatched eggs in the nest (Figure 5). We have previously observed that egg membranes will be present in the moss clumps for 25–30 days after hatching.

Figure 5.

Raccoon Procyon lotor predation damage on an uncaged four-toed salamander Hemidactylium scutatum nest at the South Holston Weir Dam in Sullivan County, Tennessee during May 2022. Tree moss Climacium americanum was detached from the log with no egg membranes remaining. Nest predation is noted inside the red circle.

Figure 5.

Raccoon Procyon lotor predation damage on an uncaged four-toed salamander Hemidactylium scutatum nest at the South Holston Weir Dam in Sullivan County, Tennessee during May 2022. Tree moss Climacium americanum was detached from the log with no egg membranes remaining. Nest predation is noted inside the red circle.

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Data analysis

We used R 4.2.1 (R Core Team 2022) to conduct a Fisher’s exact test to determine the significance of nest cage status and predation in the 2022 experiment. We selected a Fisher’s exact test due to one cell within the contingency table being less than five. We pooled data from the Bouton Tract and Weir Dam sites. We created a 2 x 2 contingency table using a distribution of values to generate a p-value of the observed data. The table coded the variables as “Caged,” “Uncaged,” “Not Damaged,” and “Damaged” while using “Yes” or “No” to create the combinations appropriately. We used an alpha = 0.05 to test if our hypothesis was statistically significant.

Nest predator identification

During our camera trapping survey from 2016 to 2019, we observed 10 vertebrate species at four-toed salamander nests, but we assumed pileated woodpeckers Dryocopus pileatus, Canada goose Branta canadensis, and Eastern cottontail Sylvilagus floridanus would not prey on four-toed salamander nests and were not included in the summary of nest visitors (Table 2). Of the 10 species observed, only two would typically prey on a salamander nest: raccoons and Virginia opossum Didelphis virginiana (Herman 2013; Hart et al. 2019). Both black bears Ursus americanus and bobcats Lynx rufus could potentially prey on nests, but we did not observe any signs of predation activity, such as digging. We only observed these larger mammals smelling flagging or fencing.

Table 2.

Predators observed visiting four-toed salamander Hemidactylium scutatum nests at the South Holston Weir Dam in Sullivan County, Tennessee, from trail cameras photos during the camera trapping survey (2016–2019). The number of cameras and total camera days are listed for each year and cage treatment. Values for each species indicate the total number of visits to the nest followed by the number of nests preyed upon.

Predators observed visiting four-toed salamander Hemidactylium scutatum nests at the South Holston Weir Dam in Sullivan County, Tennessee, from trail cameras photos during the camera trapping survey (2016–2019). The number of cameras and total camera days are listed for each year and cage treatment. Values for each species indicate the total number of visits to the nest followed by the number of nests preyed upon.
Predators observed visiting four-toed salamander Hemidactylium scutatum nests at the South Holston Weir Dam in Sullivan County, Tennessee, from trail cameras photos during the camera trapping survey (2016–2019). The number of cameras and total camera days are listed for each year and cage treatment. Values for each species indicate the total number of visits to the nest followed by the number of nests preyed upon.

Efficacy of caging to reduce predation

During the nest caging pilot study from 2018 to 2019, we observed 20 uncaged nests throughout two nesting seasons and documented raccoons preying upon five nests (24%). We did not observe any other vertebrate species preying upon nests. Virginia opossums would approach caged nests but would quickly move away. When we compared observations of species visiting caged and uncaged nests from 2018 to 2019, raccoons approached caged nests on 22 occasions, and we never observed a breach of caging or predation at caged nests (Figure 6). However, we observed raccoons at seven uncaged nests, resulting in two predation events. We did not observe any species climbing or breaching cages, including black bears. Gray squirrels Sciurus carolinensis would climb the caging and posts, but we did not observe nest predation. In 2019, one caged nest was preyed upon due to a fencing breech. A green ash tree fell on one of the cages, providing a gateway to the nest inside the cage. As a result, the nest was successfully preyed upon. Unfortunately, we had not placed a camera at this nest, and could not identify the species of predator.

Figure 6.

Raccoon Procyon lotor investing a four-toed salamander Hemidactylium scutatum nest cage in 2018 at the South Holston Weir Dam in Sullivan County, Tennessee without attempting to breach the cage.

Figure 6.

Raccoon Procyon lotor investing a four-toed salamander Hemidactylium scutatum nest cage in 2018 at the South Holston Weir Dam in Sullivan County, Tennessee without attempting to breach the cage.

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When we compared nest predation in our nest caging experiment (2022), we found that 17/120 (26%) uncaged nests had been preyed upon, and none of the 65 caged nests had been damaged. There was a significant association between predation and nest-caged status by Fisher’s exact test (P < 0.007), which indicates that caging significantly reduces nest predation. Upon inspection of the cages, there was no indication of predation. The mud surrounding the nests did not reveal any physical signs of animal presence, such as footprints or feces. There was also no direct damage to the caging material. However, preyed upon nests suffered noticeable moss damage on the outer edges of the moss clumps. Moss was ripped away, leaving remnants scattered in the mud, and large gaps were left exposed.

The objectives of our study were to 1) identify nest predators of female four-toed salamanders and 2) determine if nest cages could reduce predation of four-toed salamander nests. Our camera trapping survey revealed the presence of 10 potential predators within female four-toed salamander nesting grounds. We found raccoons to be the only documented predator of four-toed salamanders in Northeastern Tennessee. This information provided insight into which predator impacted nest success and population density before the installation of nest cages. Many of the potential predators (Table 2) have the capacity to outmaneuver the cages. This suggests that caging is a hindrance and makes trying to break the boundary energetically expensive. We did not encounter skunk Mephitis sp. predation at our study sites. This was unusual considering they are suggested nest predators of salamanders (Herman 2013).

Our study coincides with the success of nest cages used for turtle and ground-nesting bird species (Isaksson et al. 2007; Buzuleciu et al. 2015). The authors found that nest cages reduced predation levels and increased the survival of offspring. However, studies have shown that mammalian species have learned to penetrate these barriers and prey upon nests. Mustelids adapt to nesting cages and are successful in preying upon their target. Isaksson et al. (2007) noted American mink Mustela vison predation events of ground-nesting shore birds with both the incubating adults and their eggs missing from the cages. Recognizing predators that invade nest cages is crucial as it allows researchers to evaluate their design and make necessary changes to protect their target species.

We found that using nest cages to reduce nest predation significantly increases the survival of nesting female four-toed salamanders and their eggs. Our study was the first to examine how caging can be an effective conservation tool and a potential management strategy for four-toed salamanders. This, in turn, can be implemented in areas where populations are declining to help protect nests from potential predation. Although we observed no predation events from the intact caged nests, one damaged cage from a fallen tree limb resulted in a prey event. Four-toed salamanders have a noted conservation status in over half of the states they reside in (Table 1). Our study could assist in the land management of amphibians, like four-toed salamanders, with similar nesting ecology.

We acknowledge the density of raccoons at our study sites may be different within all four-toed populations. Our study sites are recreational hotspots for the public. Many local anglers come to fish in the South Holston River and hike on nearby trails. Consequently, food and trash remnants are left behind that attract wildlife, especially raccoons, to congregate in certain areas. The number of raccoons observed at our site anecdotally seems much higher than at other sites. We have frequently observed raccoons climbing out of trash cans. Riley et al. (1998) found that raccoons can rely upon urban environments, as they view it as a place to increase their chance of survival. Trash that is easily accessible provides a guaranteed meal and reduces the energy needed to forage. The authors also found that forested islands, like Osceola Island Recreation Area, can contain raccoon populations that surpass carrying capacity for unsupported areas (Riley et al. 1998).

However, we have noticed many newer recreation and interpretation trails in, and above, wetlands inhabited by four-toed salamanders (McCarthy and Hamed 2022). Visitors and trail users often generation refuse, and Riley et al. (1998) suggested that increased human activity and subsequent food waste could increase raccoon density. Smith and Engeman (2002) noted that raccoons can be problematic in public parks when left unmonitored. They focused on raccoon population density at Hugh Taylor Birch State Park (HTBSP) in Fort Lauderdale, Florida. Public parks boost raccoon populations by providing high-caloric resources that are not typical for outdoor environments. Smith and Engeman (2002) found that the raccoon density in HTBSP was approximately 238/km2. This value coincides with the raccoon density range of 66.7/km2 to 333.3/km2 revealed by Riley et al. (1998) in suburban and urban areas. At HTBSP, predator management was critical to prevent raccoons from contributing to the degradation of surrounding habitats (Smith and Engeman 2002).

There are two obstacles to using caging as a barrier. The first is maintenance due to fallen leaves from the tree canopy that get trapped inside the cage. The other is the higher proportion of vegetation growth due to the cage centralizing the spread of vegetation development and the potential decrease of herbivorous grazing. Both leaves and vegetation suppress moss growth by reducing and even blocking light. Once leaves enter the cage, they appear to be trapped. Placing a screen over the top of the cage could prevent leaves from entering and allow them to blow from the top screening. Maintenance of the cages should be done in the fall to limit the expansion of vegetation in the spring nesting season and to ensure the moss receives adequate light.

Nest caging provides a solution for land managers and is a cost- and labor-effective method to reduce four-toed salamander predation. Even with the recent material cost increase, a nest can be caged for less than US $10.00. Fencing material costs approximately US $5.00 per cage. We were able to reduce the cost per cage by US $3.50 each by modifying our cage dimensions. Lastly, we used nine cable ties per cage for a total cost of US $0.90. A team of two student volunteers could install a nest cage in less than 10 minutes. We cut our stakes prior to arriving at the field site and would require an extra three minutes per cage prior to installation.

In conclusion, four-toed salamanders can experience frequent nest predation. As a species with some level of conservation status in most states, loss of recruitment could negatively impact an already uncommon salamander. As with other species of birds and reptiles, caging nests significantly reduces predation by raccoons. Our caging method provides land managers with an inexpensive, simple, and quick method to protect nesting female four-toed salamanders, eggs, and moss nesting areas.

Please note: The Journal of Fish and Wildlife Management is not responsible for the content or functionality of any supplemental material. Queries should be directed to the corresponding author for the article.

These are references for the state wildlife action plans where four-toed salamanders reside in the United States:

Reference S1.Alabama Department of Conservation and Natural Resources. 2015. Alabama’s Wildlife Action Plan.

Available: https://www.outdooralabama.com/sites/default/files/Research/SWCS/AL_SWAP_FINAL%20June2017.pdf (18.38 MB) (January 2023)

Reference S2.Connecticut Department of Energy and Environmental Protection. 2015. Connecticut’s Wildlife Action Plan.

Available: https://portal.ct.gov/-/media/deep/wildlife/pdf_files/nongame/ctwap/ctwapchapter1pdf.pdf (7.07 MB) (January 2023)

Reference S3.Delaware Department of Natural Resources and Environment Control. 2005. Delaware Wildlife Action Plan.

Available: https://documents.dnrec.delaware.gov/fw/dwap/2015%20Submitted%20Documents/Chapter%201.pdf (2.96 MB) (January 2023)

Reference S4.Florida Fish and Wildlife Conservation Commission. 2019. Florida’s Stat Wildlife Action Plan.

Available: https://myfwc.com/media/22767/2019-action-plan.pdf (12.93 MB) (January 2023)

Reference S5.Georgia Department of Natural Resources. 2015. Georgia State Wildlife Action Plan.

Available: https://georgiawildlife.com/sites/default/files/wrd/pdf/swap/SWAP2015MainReport_92015.pdf (16.10 MB) (January 2023)

Reference S6.Illinois Department of Natural Resources. 2015. The Illinois Comprehensive Wildlife Conservation Plan & Strategy.

Available: https://dnr.illinois.gov/content/dam/soi/en/web/dnr/conservation/iwap/documents/illinoiscwcp.pdf (7.51 MB) (January 2023)

Reference S7.Indiana Department of Natural Resources. 2015. Indiana State Wildlife Action Plan.

Available: https://www.in.gov/dnr/fish-and-wildlife/files/swap/fw-SWAP_2015.pdf (10.48 MB) (January 2023)

Reference S8.Kentucky Department of Fish and Wildlife. 2013. Kentucky State Wildlife Action Plan.

Available: https://fw.ky.gov/WAP/Documents/2023_SWAP_PublicComment_AR02.pdf (37.47 MB) (January 2023)

Reference S9.Maryland Department of Natural Resources. 2015. Maryland State Wildlife Action Plan.

Available: https://dnr.maryland.gov/wildlife/Documents/SWAP/SWAP_Chapter3.pdf (3.75 MB) (January 2023)

Reference S10.Massachusetts Division of Fisheries and Wildlife. 2015. Massachusetts State Wildlife Action Plan.

Available: https://www.mass.gov/doc/state-wildlife-action-plan-chapter-3/download (478.88 KB) (January 2023)

Reference S11.Missouri Department of Conservation. 2015. Missouri State Wildlife Action Plan.

Available: https://mdc.mo.gov/sites/default/files/2020-04/SWAP.pdf (7.69 MB) (January 2023)

Reference S12.Maine Department of Inland Fisheries and Wildlife. 2015. Maine’s 2015-2025 Wildlife Action Plan.

Available: https://www.maine.gov/ifw/docs/2015%20ME%20WAP%20All_DRAFT23.pdf (11.41 MB) (January 2023)

Reference S13.Minnesota Department of Natural Resources. 2016. Minnesota’s Wildlife Action Plan 2015-2025.

Available: https://files.dnr.state.mn.us/assistance/nrplanning/bigpicture/mnwap/appendix_c.pdf (580.92 KB) (January 2023)

Reference S14.Mississippi Museum of Natural Science. 2015. Mississippi State Wildlife Action Plan.

Available: https://southeastfreshwater.org/wp-content/uploads/2015/09/MDWFP_2015_2025_2.pdf#:∼:text=This%20Mississippi%20State%20Wildlife%20Action (9.05 MB) (January 2023)

Reference S15.North Carolina Wildlife Resources Commission. 2015. North Carolina Wildlife State Action Plan.

Available: https://www.ncwildlife.org/Portals/0/Conserving/documents/2015WildlifeActionPlan/NC-WAP-2015-All-Documents.pdf (33.73 MB) (January 2023)

Reference S16.New Hampshire Fish and Game Department. 2015. New Hampshire Wildlife Action Plan.

Available: https://www.wildlife.nh.gov/sites/g/files/ehbemt746/files/inline-images/appendixa-amphibians.pdf (1.51 MB) (January 2023)

Reference S17.New Jersey Department of Environmental Protection. 2018. New Jersey’s Wildlife Action Plan.

Available: https://www.state.nj.us/dep/fgw/ensp/wap/pdf/wap_plan18.pdf (34.47 MB) (January 2023)

Reference S18.New York State Department of Environmental Conservation. 2015. New York’s Wildlife Action Plan.

Available: https://www.dec.ny.gov/docs/wildlife_pdf/hpsgcnamp.pdf (452.27 KB) (January 2023)

Reference S19.Ohio Department of Natural Resources. 2015. Ohio’s State Wildlife Action Plan.

Available: https://ohiodnr.gov/static/documents/wildlife/wildlife-management/OH_SWAP_2015.pdf (18.80 MB) (January 2023)

Reference S20.Oklahoma Department of Wildlife Conservation. 2015. Oklahoma Comprehensive Wildlife Conservation Strategy: A Strategic Conservation Plan for Oklahoma’s Rare and Declining Wildlife.

Available: https://www.wildlifedepartment.com/sites/default/files/2021-11/Oklahoma%20Comprehensive%20Wildlife%20Conservation%20Strategy.pdf (9.70 MB) (January 2023)

Reference S21.Rhode Island Department of Environmental Management. 2015. Rhode Island Wildlife Action Plan.

Available: https://dem.ri.gov/sites/g/files/xkgbur861/files/programs/bnatres/fishwild/swap/SGCNHerps.pdf

Reference S22.South Carolina Department of Natural Resources. 2015. South Carolina’s State Wildlife Action Plan.

Available: https://www.dnr.sc.gov/swap/main/chapter2-priorityspecies.pdf (3.14 MB) (January 2023)

Reference S23. Tennessee Wildlife Resources Agency. 2015. Tennessee Wildlife Action Plan. Available: https://www.tn.gov/content/dam/tn/twra/documents/swap/gcn/Swap15_Amphibian.pdf (84.17 KB) (January 2023)

Reference S24.Virginia Department of Wildlife Resources. 2015. Virginia’s 2015 Wildlife Action Plan.

Available: https://dwr.virginia.gov/wp-content/uploads/media/Wildlife-Action-Plan-Final-SGCN-List-Appendix-A-July-2016.pdf (1.93 MB) (January 2023)

Reference S25.Vermont Fish and Wildlife Department. 2015. Vermont’s Wildlife Action Plan.

Available: https://vtfishandwildlife.com/sites/fishandwildlife/files/documents/About%20Us/Budget%20and%20Planning/WAP2015/A1.-Amphibian-%26-Reptile-SGCN-%282015%29.pdf (4.41 MB) (January 2023)

Reference S26.Wisconsin Department of Natural Resources. 2015. Wisconsin Wildlife Action Plan.

Available: https://dnr.wisconsin.gov/topic/WildlifeHabitat/actionPlanSGCN#:∼:text=Species%20of%20Greatest%20Conservation%20Need (205 KB) (January 2023)

Reference S27.West Virginia Department of Natural Resources. 2015. West Virginia State Action Wildlife Action Plan.

Available: http://wvdnr.gov/wp-content/uploads/2021/05/2015-West-Virginia-State-Wildlife-Action-Plan-Submittal-1.pdf (42.62 MB) (January 2023)

Reference S28.Fowler H. 2015. Arkansas Wildlife Action Plan. Arkansas Game and Fish Commission, Little Rock, Arkansas.

Available: https://www.agfc.com/wp-content/uploads/2023/04/04-Amphibians.pdf (2.75 MB) (January 2023)

Reference S29.Holcomb SR, Bass AA, Reid CS, Seymour MA, Lorenz NF, Gregory BB, Javed SM, Balkum KF. 2015. Louisiana Department of Wildlife and Fisheries, Baton Rouge, Louisiana.

Available: https://www.wlf.louisiana.gov/assets/Resources/Publications/Wildlife_Action_Plans/Wildlife_Action_Plan_2015.pdf (12.22 MB) (January 2023)

We would like to thank Tennessee Valley Authority for project funding and logistical support. We also want to thank the Tennessee Wildlife Resource Agency for providing a collection permit. This project would not have been possible without the help of undergraduate volunteers from Virginia Highlands Community College and the Virginia Tech Department of Fish and Wildlife Conservation. We would also like to thank the Associate Editor and two anonymous reviewers for their comments that significantly improved our manuscript.

Any use of trade, product, website, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government.

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Author notes

This Online Early paper will appear in its final typeset version in a future issue of the Journal of Fish and Wildlife Management. The findings and conclusions in this article are those of the author(s) and do not necessarily represent the views of the U.S. Fish and Wildlife Service.