There are three color variations of salamander, above. The James River Park system sees mostly the leadback (top) and redback (middle). (Photo by John White)
By Marina Winkler
Hidden under foliage and fallen trees, tiny amphibian feet skitter up and down small burrows under the cover of wooden boards. Suddenly, the board is lifted to reveal the sun-dappled faces of students, each with green halos from the trees high above. Soft hands, dirty from foraging through the leaf litter, scoop up the small creatures that are one of the James River park’s many hidden treasures: eastern red-back salamanders (Plethodon cinereus).
Every week, University of Richmond students in Dr. Kristine Grayson’s biology lab hike along the winding trails of the James River Park to check their salamander study plots. There are four plots, each consisting of five rows of ten 10-by-10 wooden boards. The data collected today will be used to further understand population demographics and to get a more accurate population size estimate.
Although lizard-like in appearance, salamanders are amphibians, and depend heavily on the availability of water either in vernal (seasonal) pools or in the soil. They breathe water, either through gills or through their skin directly. Like many aquatic and semi-aquatic species, they are sensitive to pollution and changes in water quality, making them important indicator species that let scientists know that environmental conditions are suffering in an area. Eastern red-back salamanders are fully terrestrial, but do breathe through their skin, and have a shiny layer of mucus coating their body. The species have two main coloration patterns, an all-black body (“lead-back”) or a black body with red stripes (“red-back”), which seems to be purely a cosmetic difference.
The data on them collected by Dr. Grayson’s students will be added to a region-wide project called the SPARCnetwork. Covering the known range of eastern red-back salamanders, this network of biologists aims to understand how these salamanders are responding to climate change, in addition to what biotic and/or abiotic factors influence its population dynamics.
Map of Eastern Red-Back Salamander research network (from http://sparcnet.org)
Today, however, there seemed to be fewer salamanders than usual. Two of the students, Khaela Sanchez and Dennon Hoering, talk about why.
“It might be the vegetation,” suggests Sanchez. A biology senior and a seasoned salamander survey veteran, she conducts herself with a quiet confidence.
“Maybe the tornado?” Hoering adds, referring to a twister that touched down in this area the night before. Brushing his curly, brown hair out of his face, Hoering is a freshman, the youngest of the group, and moves enthusiastically from plot to plot.
Madelyn Hair, a third student, remains focused on the task at hand. She is efficient, her long, light brown hair tucked behind her ears as she collects soil samples and records the critter counts as they’re called out by Sanchez and Hoering.
“A-3, nothing,” Sanchez announces .
“C-7, one lead adult, one red juvenile,” Hoering says.
Their words penetrate the calm of the forest, peppered by distant birdsong.
The James River park area is the southernmost extent of the salamander’s habitat range. They have historically done extremely well in this area, and part of Sanchez’s work is figuring out what, if any, abiotic factors (such as soil moisture or temperature) are key to salamander survival. The study plots are separated from the river by a train track, so while the animals don’t require direct access to the James, the protection that the park offers very likely contributes to their success here.
“The James River park system is dedicated to the conservation of native plants and animals,” Sanchez explains. “They are very strict about the alteration of land.”
The four study plots aren’t the only areas where these salamanders can be found in the James River Park System—a lucky park-goer might catch a glimpse of small, wriggly bodies under fallen wood or overturned stones.
Another species, the spotted salamander, makes use of the vernal ponds formed from heavy spring/summer precipitation or receded river waters to mate and lay their eggs. They undergo a tadpole-like form before developing into adults, which will eventually migrate back to the area where they hatched.
A spotted salamander (Ambystoma maculatum) found at one of the lower study plots. (Photo by Marina Winkler)
One of the salamander study sites. If you weren’t looking for it, you’d have a hard time seeing it was there, especially in the spring. (Photo by Marina Winkler)
As endearing as these small, hidden wonders are, and as important as they are as indicator species, there is still a lot more research to be done. What impact might chemical runoff have? Will a warming climate impact the formation of vernal pools for spotted salamanders? Will increased temperatures make the ground too warm for eastern red-back salamanders? It’s crucial to preserve the habitat they live on now, which fortunately is largely protected through the James River Park System.
Given that it’s a space available for public use, however, it’s up to the citizens who enjoy the park to help keep it healthy for all its critters, large and small.