Since last year, I have been participating in undergraduate research focusing on the population ecology of the red-backed salamander (Plethodon cinerus). I created a poster that will be presented at the showcase of excellence on May 2nd, and I’m very excited. I had such a great experience participating in thus research. I got to learn so much and gained a lot of field work experience, that will helpfully help me get a job once I graduate. It all started during the first semester of my Junior year here at PSU. I was taking Biology II taught by Kerry Yurewicz and she had mentioned something about possible internships for students that they could participate in over the summer. I was intrigued and decided to speak with her about my interests, mainly salamanders. We spoke and she didn’t have any opportunities for me when it came to internships, but said she would let me know if another opportunity arose. And it did! She invited me and couple other students to accompany her and another graduate student to the Hubbard Brook Experimental Forest in Woodstock, NH. They had already begun their research and had let us join them. It has been such a great experience and I really enjoyed my time with them doing this research. I will include some snippets from my poster below and a little more information on the study we conducted. Enjoy!
The Red-Backed Salamander (Plethodon cinereus) is a widely distributed terrestrial salamander species that can be found in high abundances across northeastern United States and into Canada. It is a lungless species that does not require aquatic settings to breed. Unlike most amphibian species, this salamander does not have an aquatic larval stage. Young are born with the appearance of small adults and will grow to be up to 10 cm. They breed June through July and females will lay their eggs in dark, damp areas in fallen logs or under rocks. They are an effective indicator species because of their sensitive skin. It is also incredibly porous allowing for gas and liquid exchange, making them sensitive to any environmental changes.
Our data collection took place within the Hubbard Brook Experimental Forest in Woodstock and Thorton, New Hampshire. Six plots were distributed within the western part of the forest. Each plot included 50 1ft x 1ft wood cover boards set up equidistant from each other in rows of 5. Each board had its own letter/number label, so we were able to return captured salamanders back to whichever board they were found under. The capturing process began with us each taking to one row of the boards and going to each and lifting carefully checked for salamanders under each. Once a salamander is found, we collected it and placed it into a plastic ziplock bag. We then labeled the bag with the letter/number label in correlation with which board it was found under. Once each plot had been visited, we then returned to the lab for analysis. We record data in regard to sex, size, tail loss, and whether it was new or a recapture. Each salamander caught was measured in mm.
Two measurements were recorded; SVL (snout vent length- measuring from the snout to the beginning of the vent) and total length including the tail. If the SVL was under 35mm, we recorded it as a juvenile. If it was over 35mm, we determined whether it was a male or a female. This was possible by looking at the snout of the salamander. During breeding season, males have bumps by their nostrils called cirri. If the individual being observed did not have cirri, we then used a flashlight to shine through the abdomen to see if any testes were visible. This method could also be used to see if any eggs were present, which would lead us to mark this individual as a female. If this was the case, the number of eggs would be recorded. We also determined whether or not each individual was new or had previously been recaptured. We could determine this by shining a UV light on the underside of each salamander to see if the colored marks were present, if they were, we recorded it as a recaptured individual. We were then able to look back at previous records to see where this salamander had been found before, if it had moved, whether it was a male, female or juvenile, or any changes overall. Once all of this information was gather from each salamander collected, we went back out into the forest and visited each plot once again. We then returned each salamander back to whichever coverboard it was found under.
In our surveys, if we just estimated abundance based on number of captures per plot at the surface, we would estimate 0.2 salamanders per m2.. Using a mark-recapture method gives us a fuller picture of the population and yields an estimate of 1.8 salamanders per m2. Key insights will be gained by comparing our data with other sites that use the same methods that we did.