Student searches for evidence
of deadly fungus among salamanders © June 25, 2010, Norwich University Office of Communications
Barefoot and perspiring, Hunter Twombly dipped a hand net into a channel of clear, mountain stream water and wrenched out a flat rock with his other hand. The water instantly became cloudy with silt, and he cupped it with his hands, trying to channel the icy flow into the net.
“If you don’t get it that first second, you’re not going to get it at all,” he murmured, shaking and poking at debris at the bottom of the net to inspect its contents. A second later, Twombly gave a small cry of triumph and held up his hand for inspection. It held a three-inch, wriggling body he identified as a northern two-lined salamander.
“They’re feisty and they’re quick and they don’t want to stay still,” he said, closing his hand to hold the tiny creature.
Twombly, a biology student, was spending the first weeks of his summer scrambling about the steep, rocky terrain of bitter-cold Vermont streams and ponds, digging up rocks, pawing through mud and tearing apart rotten logs. He was searching for different species of salamander that live in Central Vermont, home of Norwich University, to determine if any have been carrying a type of fungus at the center of a growing ecological crisis.
The fungus, Batrachochytrium dendrobatidis [Bd], is a parasite that has been identified as having infected and decimated amphibian species—particularly frogs—worldwide. The bulk of research has been performed in Italy and South America, but Bd has been found in the United States and there is evidence it also affects salamanders. Nothing is known about the presence of Bd in Vermont, which is where Twombly comes in.
“Maybe I’ll find something. Maybe I won’t,” he said. “Nobody’s done any research in Vermont.”
Twombly plans to collect at least 25 samples of DNA from all salamander species native to the area, and reproduce the DNA strand sequences through polymerase chain reaction, a technique in microbiology that will help him compare genetic material with a control sample of infected DNA provided by researchers at the University of Maine.
Right now, Twombly spends most of his time hunting the elusive creatures.
“You can search for eight hours and not find a thing,” he said, brushing a deer fly from his forehead.
Twombly wants to find adult salamanders, particularly hard-to-find red-back and mole species, but he uses older juveniles large enough to withstand the sampling procedure without too much trauma.
Setting the net with the captured northern two-lined in a shallow puddle of water, he unpacked plastic sample tubes from his backpack and struggled to pull latex gloves onto his wet hands. Then, Twombly rubbed a cotton swab over and around the light brown belly of the creature and deposited it in the test tube. He noted data including the location, time and weather in a notebook, and set the salamander free.
Shouldering his pack, Twombly moved farther up the creek, keeping up a stream of comments about tree species, lack of insects on cloudy days and his frustration with the trash and debris left by previous visitors. An Army ROTC student at Norwich, the country’s oldest private military college, Twombly plans to pursue a Ph.D. in marine or molecular biology.
“I’ve loved animals and wildlife as long as I can remember,” he said. “Bio’s my thing. It’s my passion. It’s what I really want to do.”
Twombly first thought of studying Bd in salamanders while reading an article about the spread of the fungus among frogs in a magazine provided by biology Prof. Bill Barnard, who became his mentor in the project. With the professor’s help, he applied for a grant that allows him to live on campus during the summer and earn a stipend during the research.
Barnard said he had been paying attention to research on the fungus, and believes Twombly came up with a project that is both interesting and relevant. It is a baseline step in determining if Bd exists in Vermont. If the fungus is discovered, it provides evidence that Bd can exist in this habitat, and perhaps which species of salamander are vulnerable. It is a process that will require substantial future research, he said.
“Whether we find it or not is irrelevant,” said Barnard. “It’s still valuable information. That’s how science operates.”
Twombly is looking forward to spending time in the woods with Barnard, and called him a great resource. “He knows all the locations: where to go, what to look for and where to find them.”
Barnard added there will be a lot of work to do in the laboratory once they have an adequate supply of DNA samples.
“It will be hard to reel [Twombly] in and make him sit on a lab bench during sunny days.“