Salamander study north of Eagle Rock reveals a number of species

Natalie Claunch, PHD post doctorate work includes studies of Botetourt area salamanders for fungal disease here on the 850 acre Hundley Farm north of Eagle Rock.

Some of this material is technical but there are a number different species living in woods and wet areas and near the stream. Her family accompanied her on the study one day. Her Father Eric Claunch said,

” No salamanders were harmed during the research!” Read on as Natalie explains her research and how no salamanders were harmed. Photos by Claunch family. She is the daughter of Eric and Wendy Claunch of Eagle Rock.

Chytridfungal pathogens cause disease in frogs and salamanders and are responsible for mortality and population declines in some species. There are two main disease-causing members of this group- Batrachochytrium dendrobatidis or Bd and Batrachochytrium salamandrivorans (also known as Bsal). While Bd is endemic to the Appalachians- that is, it is present in the US and has not been implicated in large population declines- Bsal is not yet present in the wild in the US.

The potential emergence of Bsal in the USA threatens salamander populations, as the Appalachian mountains contain the highest diversity of salamander species in the world. Many of these species belong to a family of salamanders that do not have lungs (Plethodontidae)- so they rely solely on their skin to breathe. Because these fungal pathogens attack the skin (the species name of Bsal, salamandrivorans, literally translates to “salamander-eating”), these lungless salamanders are especially at risk if infected with these chytrid fungi.

Several studies have been conducted to evaluate disease risk of Bsal in the laboratory with many species, but these are all conducted at a single temperature, optimum for growth of Bsal. These controlled experiments are important, but do not account for how salamanders may behave in the wild, when they have access to different thermal environments. Salamanders are ectotherms- meaning their body temperature changes based on their environment. Some would call this “cold-blooded”, but they are only “cold-blooded” in cold places, when they are in warmer microhabitats they are also warm!

Little is known about thermoregulation habits of amphibians, especially salamanders, so it is important to fill gaps in this knowledge to make disease-risk projections. The aim of our study in Virginia is to collect thermal preference and thermal microhabitat data from several species of salamanders and use this information to project disease susceptibility risk across the landscape. To do this, we collect individual salamanders and place them in a thermal gradient, which gives them the choice of cool and warm temperatures. We record their body temperatures in the gradient for a set amount of time. We do this for many individuals of each species to collect the average and variation in preferred temperatures. After the trial is finished, the salamanders are measured, inspected for signs of disease, and then their skin is swabbed to pick up any traces of fungal pathogens present.

The salamanders are returned to their exact capture location, where we record microhabitat data (were they under a log, or rock, and what temperature it was underneath any cover). We take the swabs back to the laboratory and extract DNA from them and perform a technique called qPCR which allows us to quantify how many copies of our target pathogens may have been present (if any). We do not expect to detect Bsal in any samples, but we are interested in surveillance of Bd and how it may affect the salamander behavior in thermal gradients. All of our equipment and supplies are thoroughly sanitized between sites and individual salamanders to ensure we do not expose individuals to disease during our experiments. Once all of this field data collection is complete, we will combine the thermal data with known disease susceptibility data and local climate data to forecast the potential disease risks for different species and different areas.

This is a component of a multi-part project supported by National Science Foundation Postdoctoral Research Fellowships in Biology Program under Grant No. 2109663, and Florida Museum of Natural History Travel Grant to Dr. Natalie Claunch. This project is approved by University of Florida Animal Care and Use Committee #IACUC202200000035, Virginia DWR Permit # 3531640, and USDA nominal effects determination #2620 for sampling in George Washington and Jefferson National Forests. This portion of the project is also being conducted in collaboration with the Virginia Museum of Natural History.

Be on the look out for Salamander photos in our Facebook story over the next several weeks as we meet our amphibian Neighbors!

–Dr. Natalie Claunch and Cathy Benson with Ed Claunch photos

This story has been edited