• Added Value: Systematic Gopher Tortoise Surveys Provide Estimates of Gopher Frog Abundance in Tortoise Burrows
  • Lora L. Smith; Jennifer M. Howze; Jennifer Staiger; Eric Sievers; Deborah Burr; Kevin Enge
    The gopher frog (Lithobates capito) is under review for listing under the U.S. Endangered Species Act. Much of our knowledge on the status of gopher frogs is based on detections of larvae at breeding wetlands, but little is known about abundance of the species in its terrestrial habitat. We recorded observations of gopher frogs during gopher tortoise (Gopherus polyphemus) surveys during which a camera was used to search burrows and we used distance analysis to estimate frog abundance at 4 Florida conservation lands. We also recorded burrow size, incidence of frog co-occupancy with tortoises, and distance from burrows to breeding wetlands. We observed 274 gopher frogs in 1,097 tortoise burrows at the 4 sites. The proportion of burrows occupied by frogs among sites ranged from 0.17-0.25. Frog abundance in tortoise burrows was 742 (512-1,076 95% CL) at Etoniah Creek State Forest, 465 (352-615) at Ft. White Wildlife Environmental Area, 411 (283-595) at Gold Head Branch State Park, and 134 (97-186) at Watermelon Pond Wildlife Environmental Area. The proportion of frogs in burrows occupied by a gopher tortoise ranged from 0.20-0.72 and frogs used burrows from 7-43 cm in width. Distance from frog-occupied burrows to the nearest breeding wetland ranged from 141-3,402 m. Our data on gopher frogs collected in conjunction with gopher tortoise monitoring efforts using distance sampling and burrow cameras provided novel information on frog abundance in their terrestrial habitat. However, our abundance estimates were limited to the portion of the population inhabiting tortoise burrows, and the extent to which frogs use tortoise burrows over other available refuges (small mammal burrows, stumps, or other structures) is unknown. Nonetheless, recording gopher frogs in burrows during tortoise surveys required no additional effort and abundance estimates derived from these data may prove useful in detecting population trends in this cryptic species.

  • Reproductive Phenology of Red-Backed Salamanders Near the Southern Range Edge*
  • Madelyn A. Hair; Hannah M. Coovert; Kristine L. Grayson
    Red-backed salamanders, Plethodon cinereus, are a common terrestrial salamander known for their role in forest food webs and nutrient cycling across the northeastern United States. Surface activity duration of such terrestrial salamanders is based on tolerance limits to temperature and moisture. Populations in northern or mountainous regions experience bimodal surface activity in spring and fall due to large seasonal changes in climate, whereas the surface activity of southern populations is less constrained during mild winters and more limited in summer under hot and dry conditions. We are examining the seasonal differences in surface activity in a southern population of P. cinereus, and the effects of temperature on reproductive timing and juvenile recruitment. Our dataset includes four years of field surveys (2016 – 2019) using artificial cover boards in a suburban park in Richmond, Virginia. This population has been documented to have an unusually high population density from spatial-capture recapture analyses. We examined the association between seasonal and yearly differences in adult salamanders with observable eggs, and the proportion of juvenile salamanders compared to adults. Females were observed with eggs most frequently in February, with another peak of visible eggs in November. Juvenile salamanders were observed more frequently in April and October, suggesting two opportunities for reproduction each year in southern populations. Defining the relationship between temperature and reproductive success in P. cinereus is critical for understanding the effects of climate change in a common forest salamander. Responses of this species to temperature at the southern range edge can provide insights on its capacity for plasticity in a rapidly warming world.

  • Created Managed Ephemeral Wetlands As Habitat for Amphibian Populations in Western Kentucky
  • Andrea N. Drayer; Jacquelyn C. Guzy; Rachel Caro; Steven J. Price
    Loss of wetlands worldwide has necessitated the creation of wetlands. Yet, the physical attributes and community composition of created wetlands often differ compared to natural wetlands. We surveyed three types of ephemeral wetlands [managed open canopy (MOC), unmanaged open canopy (UMOC), and unmanaged closed canopy (UMCC); managed = created wetlands with water control structures] in western Kentucky to estimate amphibian richness and occupancy among wetlands, and estimated abundance of three common species: Southern Leopard Frog (Lithobates sphenocephalus), Spotted Salamander (Ambystoma maculatum), and Crawfish Frog (L. areolatus). In addition, we quantified variability in physical characteristics and water quality parameters among wetland types. MOC wetlands had a greater percent of submergent vegetation than both UMCC and UMOC wetlands, shallower depth at 1.0 m from the wetted wetland edge than UMOC wetlands, and larger wetland surface area than UMCC wetlands; water quality values were highest at UMCC wetlands. Mean predicted amphibian species richness and occupancy was highest at larger wetlands. Occupancy of the three locally common species was not influenced by wetland management type and varied little among species. Estimated abundance of L. areolatus, a species of conservation concern, was higher at MOC wetlands, and conversely, Am. maculatum abundance was highest at UMCC wetlands. Wetlands with greater surface area had higher estimated abundances of L. areolatus and L. sphenocephalus. Our results suggest created, large, managed open canopy wetlands are important conservation tools for the overall amphibian community and function to augment local populations of amphibian species of conservation concern (i.e. L. areolatus).

  • Monitoring Strategies for Repatriated Eastern Indigo Snakes in Southern Alabama*
  • Francesca T. Erickson; Conor P. McGowan; James C. Godwin; Daniel V. Young; Craig Guyer
    The Eastern Indigo Snake (Drymarchon couperi) was extirpated from Alabama in the 1950s and was declared threatened throughout its range under the Endangered Species Act in 1978. In 2010, a repatriation program began in Conecuh National Forest (CNF), and now that ten years have passed since the inception of the program, monitoring of this population is crucial. Previous projects in CNF involved radio tracking indigo snakes after release and looking at release methods, home range, and habitat selection. However, since 2014, monitoring has been restricted in temporal scope and sampling methods. Monitoring of a population after reintroduction is crucial in determining population size, survival rates, reproduction and the success of the reintroduction effort. We are evaluating five different monitoring methods: the previous radio tracking data, intensive pedestrian surveys, camera trapping, remote RFID readers and passive box traps. Our objectives are to evaluate multiple monitoring methods with respect to the value of information gathered and monitoring costs. In 2019, increased pedestrian surveys and box traps successfully yielded an increased magnitude of encounters and captures of released snakes. In 2020 camera traps recorded indigo snakes at multiple gopher tortoise burrows, however individual IDs could not be made. We will deploy remote RFID PIT tag readers by placing antennas around tortoise burrows in 2020 and 2021. This will allow for identification of all PIT-tagged individuals using a burrow, when, and how often. These five methods all show potential for success, but have different costs and quality of gathered information. We will analyze data via occupancy modeling and N-mixture modeling, and aim to make abundance and survival estimates. We can then make recommendations on the best and most cost-effective methods of monitoring this species.

  • Research and Teaching Opportunities with a Large-Scale Salamander Collaboration Network (SPARCnet)
  • Kristine L. Grayson; Caitlin Fisher-Reid; Louise Mead; Hannah Coovert; Raisa Hernández Pacheco; Jennifer Sevin; Sean Sterrett; Chris Sutherland; David Muñoz; David Miller; Evan Grant
    Understanding wildlife responses to climate change has never been more urgent. For species with wide geographic ranges, there can be substantial variation in population processes and the effects from environmental change. Terrestrial salamanders in the genus Plethodon are often used in ecological studies as a key component of forest ecosystems, where lungless respiration through their skin and high abundance serves as a commonly used indicator of forest health. The eastern red-backed salamander (P. cinereus) is the most widespread and commonly studied species, yet most studies focus on local population dynamics. Understanding larger scale spatiotemporal patterns in population dynamics in relation to climate requires expanding beyond studies at single institutions. The Salamander Population and Adaptation Research Collaboration Network (SPARCnet) was founded in 2013 by researchers at Pennsylvania State University and the USGS Northeast Amphibian and Research Monitoring Initiative (NEARMI). It has since grown to include collaborators at 19 institutions and 8 education organizations. SPARCnet aims to provide a consistent framework for understanding population trends in P. cinereus, while delivering education opportunities for students. Researchers, educators, and citizen scientists apply the same cover-board plot study design and sampling methods across the range of the salamander in eastern and north-central North America. Most participants mark the salamanders they find, and thus have long-term spatial-capture-recapture data, along with basic population demographic data. Educators at these institutions are also developing course-based research modules available as open education resources for collaborative teaching. This network serves as an important model for bringing field research to students and building robust population data for species with wide geographic ranges.

  • A Review of the Chigger Infested Amphibians in the United States and Mexico
  • Kristin A. Bakkegard
    Chiggers are the parasitic larval form of mites which infest all terrestrial vertebrates. In amphibians, chiggers burrow in and under the skin and have the potential of harming the infested animal through mechanical damage to skin and limbs, decreased reproductive success, or by introducing a pathogen. The discovery of chigger infested Northern Slimy Salamanders (Plethodon glutinosus), in north-central Alabama prompted a literature review, starting with the earliest record in the United States (1921) to the present, of chigger infested amphibians in the United States and Mexico. Data collected included the host, its chigger species, state, and county (if provided) to generate a map of chigger infesting amphibians and to look for patterns in the host-parasite relationship. Two of the six genera of chiggers that infest amphibians, Hannemania (an amphibian specialist) and Eutrombicula (a vertebrate generalist) are found in the United States and Mexico. Chigger infested amphibians have been reported in 20 US and 13 Mexican states. In the US, three species of Eutrombicula and seven species of Hannemania are known to infest amphibians. In Mexico, there is one species of Eutrombicula and at least six species of Hannemania known to infest amphibians. In the United States, 26 species of salamander and at least 28 species of frog are hosts. In Mexico, one salamander and at least 18 species of frog are hosts. The chigger mite with the largest geographic range is Hannemania dunni. I encourage others to publish their observations of chigger infested amphibians in order to better understand the host-parasite relationship and the risk they may pose to populations and species.

  • Corticosterone Levels and Heterophil to Leucocyte Ratios in Response to Parasitism in Wild Cottonmouth Populations*
  • Emma Fehlker Campbell; John B. Hewlett; Andrea K. Darracq
    Helminth endoparasites and hemoparasites are frequently found in wild populations of Cottonmouth (Agkistrodon piscivorus), but little is known about their physiological effects on wild populations. Additionally, these parasites may interact with diseases, including snake fungal disease (SFD) which is caused by the fungus Ophidiomyces ophiodiicola (Oo). To our knowledge few studies have assessed potential interactions between SFD and parasites in snakes. Thus, the objective of our study is to assess the individual and interactive effects of Helminth endoparasites, hemoparasites, and snake fungal disease on cottonmouth physiological stress. We are using two measures of stress; corticosterone (CORT), which is the primary stress hormone excreted by cottonmouths, and Heterophil to Leucocytes (H/L) ratios in the blood, which generally correlate with CORT levels. We collected 20 cottonmouths (> 300 g) from three populations in Western Kentucky. Within 3 – 5 minutes of capture we collected blood from the caudal vein of each snake to quantify baseline CORT. Additionally, helminth presence was determined by counting parasites in the oral lining, snakes were assessed for lesions consistent with SFD, and each snake was swabbed for future determination of SFD status using qPCR. From each blood sample, a thin smear was made using Giemsa-Wright stain. Using the smear, hemoparasites were identified and counted and H/L ratios were determined under 1000x magnification. We will present preliminary results from these data.

  • Utilization of Cameras to Monitor Arboreal Habitat Use by Green Salamanders
  • M. Kevin Hamed; Walter H. Smith
    Green salamanders (Aneides aeneus) have been increasingly observed in arboreal habitats. However, a reliable method has not been identified to maximize arboreal detections. We evaluated traditional visual tree inspections against camera-assisted surveys during 2019 at sites with known green salamander occurrences across southwest Virginia. Traditional surveys consisted of visually inspecting tree surfaces with binoculars to document arboreal surface activity. Though we occasionally observed green salamanders on tree trunks, our observations when using this method were sporadic. We then implemented monitoring, assisted by two different camera devices. We used a Whistler borescope to inspect any tree refugia (knotholes, hollow stems), searching every tree we could safely access within ~10 m of rockfaces. In 2020, we also mounted Recoynx XR6 trail cameras to face trees that could have green salamander activity. We visually inspected photographs to determine green salamander arboreal activity. We found that borescopes can dramatically improve salamander detections in trees, particularly for animals in stem or trunk refugia, with an up to tenfold increase in encounter rates observed for borescope-assisted surveys compared to traditional tree surface surveys. We also found that salamanders tended to use the same refugia repeatedly, and they were typically in those refugia following periods of wet weather. Trail cameras were effective at documenting tree use. Arboreal habitat use was greatest during and within 24 hours of a precipitation event. Our results suggest arboreal habitat use is even greater than previously thought and that cameras provide an effective tool for studying this mode of habitat use.

  • Assessment of Turtle and Leech Parasite-Host Assemblage Variation in Middle Tennessee Wetlands Across a Disturbance Gradient
  • Laura Horton; Bill Sutton
    Prior research has established clear links between decreased reptile biodiversity in degraded or disturbed habitats, including chelonian groups. There are negative impacts associated with high parasite loads on hosts, and previous studies found parasite loads increase with habitat disturbance, however there have been no published attempts to evaluate detectable sublethal health effects associated with this potential increase in chelonian ectoparasite (leech) load. Thus we assessed if leech loads varied across a landscape disturbance gradient in Middle Tennessee wetlands and if they follow measurable patterns of increased sublethal health effects on chelonians by assessing heterophil:lymphocyte ratios, packed cell volume, and host body condition. We sampled 19 wetlands from June-October 2018 and obtained data from three host species; Trachemys scripta elegans, Sternotherus odoratus, and Chelydra serpentina. Collectively, the interpretation of these data may be used to understand how anthropogenic disturbance affects wetland turtle-leech communities and potential associated health implications.

  • Terrestrial Salamander Community Dynamics and Trophic Ecology in Pacific Northwest Forests*
  • Christopher Cousins; Tiffany Garcia
    Terrestrial (Plethodontid species) salamanders have the highest abundance of any vertebrate groups in North American forests, yet their community and trophic ecology in the Pacific Northwest remains understudied. Found in multiple microhabitats, their ecological role in linking the forest floor, canopy, and aquatic systems is vital to understanding forest ecosystem function and health. As predators of decomposer invertebrates, salamanders have strong impacts on leaf litter decomposition rates, affecting nutrient transfer and carbon sequestration. Our project will shed light on the role of Plethodontids as conduits of energy transfer between habitats, on the functional role that they play controlling arthropod communities, and how their trophic ecology changes depending on community assemblage. Sampling sites are within experimental forests in western Oregon that contain forest stands varying in Plethodontid biodiversity and stand age to understand prevalence of niche portioning and impacts of habitat disturbance on community networks. We will use a combination of active and passive survey results (e.g. terrestrial and arboreal artificial cover objects) that characterize the top-down control of Plethodontids on invertebrate populations. Our study focuses on prey functional class (decomposers, defoliators, etc.), allowing us to investigate Plethodontid impacts on forest health. This information is necessary for the prediction of how Plethodontid and arthropod communities will respond to changing climates. Broader impacts of this work include the effects of arboreal plethodontids on key arthropods in the forest canopy, a topic of concern to forest managers. This study will shed light on how the community ecology of this highly abundant group of vertebrates maintains forest health, and how it changes relative to timber harvest and stand age.


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