Scott Winton organizes his life around birds.
He vacations where there are birds to see. He likes biking better than driving because it’s easier to hear and see birds. And if he does drive, he gets out of the car with his head up, listening and looking.
Wherever he’s lived – Rhode Island, Scotland, Australia and Ecuador -- Winton has been active in bird clubs, which he says are great places to make friends. He currently has about 1,100 of them as the vice president of the Carolina Bird Club, which encompasses North and South Carolina.
For now, he’s back in Durham, his hometown, earning a PhD in environmental science and policy at the Nicholas School of the Environment. But after he graduates, he’d love to have a postdoctoral position in Australia, partly because of its proximity to southeast Asia, where there are whole new bird families to explore.
For his dissertation, Winton is studying the effect of waterfowl on greenhouse gas emissions at Lake Mattamuskeet National Wildlife Refuge in eastern North Carolina, the state’s largest freshwater lake and winter home to hundreds of thousands of migratory waterfowl.
After hearing a conference presentation about how vegetation-eating waterfowl can mediate methane emissions in wetlands, he realized he could combine his birding passion with his professional life.
“Wetlands are usually really tough to work in, which has been a barrier for many people,” Winton says. “That means that if you’re willing to don hip-waders and do some slogging, it isn’t too difficult to come up with some novel research questions.”
Wetlands also play crucial role in climate change: “They store one-third of the world’s soil carbon and at the same time they emit about one-third of global methane, which is a potent short-lived greenhouse gas,” Winton said.
Wetland plants transport methane from the soil into the atmosphere. They also transport oxygen from the atmosphere into the soil, where it both reduces methane production and encourages the growth of methane-eating bacteria.
Watch a 5-minute story about the over-wintering waterfowl from WUNC-TV.
So, what happens when a quarter-million or more ducks and swans spend a couple of months nibbling and digesting that vegetation? Every winter, Mattamuskeet hosts about a third of the Atlantic population of tundra swans and about 10 percent of the dabbling ducks.
To find out, Winton set up 16 study plots, 2-meter by 2-meter squares. Half the study plots were left open to grazing waterfowl and half were fenced off with plastic deer fencing. Once a month, he collected gas and soil samples from each of the study plots.
When he analyzed the data, he was surprised to discover that the plots protected from grazing emitted less methane than those where waterfowl grazed freely.
“My thought was the ducks and swans would be heroes because they would reduce the plants’ ability to move methane out of the sediment,” Winton says. “But what I found was that by eating the plants, they were reducing the amount of oxygen making it into the soil.”
So are birds the bad guys? “That’s a question I’ve been wrestling with a lot because I’m a big fan of birds,” he says. However, he points out that his study was a “binary experiment:” comparing zero birds in the sealed plots versus the highest concentration of waterfowl on the East Coast.
“All I know is, if you have this many ducks and swans, it tends to have a bad effect,” Winton says. “It’s hard to blame that on the birds—they are going where the habitat and food are. The management has done a good job creating good habitat, adding more impoundments, maximizing bird food at the site. At the same time, because of coastal development over last decade, a lot of other aquatic bird habitat has been degraded or destroyed so there’s really been a concentration effect.” Winton says more studies are needed to see how moderate concentrations of birds affect methane emissions.
Winton also discovered that the timing of seasonal draining of impoundments around Lake Mattamuskeet affects methane emissions. When the dropping water level exposes wetland soils, they become oxidized and production of methane plummets. The second year of his study, the impoundments happened to be drained about a month earlier than the previous year, and the season’s methane emissions were reduced by two-thirds.
Winton’s work can be used to inform management decisions at Mattamuskeet and other wetlands. “If you understand that waterfowl habitats have the potential to produce a lot of methane and you have an idea of what your baseline is, then there’s an opportunity to modify bird density or hydrologic management to reduce that.”
On top of his dissertation work and his birding, Winton still finds time to serve on Duke’s Graduate and Professional Student Council (GPSC), the Campus Sustainability Committee, and the Duke student chapter of the Society of Wetland Scientists.
As part of his work on the GPSC, he has helped make the campus more bird-friendly, by helping to save wooded areas on campus and to raise awareness of bird death due to collisions with windows. (In response, Duke staff applied patterned film to the glass hallways of the Fitzpatrick Center this summer.)
Winton is also teaching a class of his own design -- Biodiversity Issues and Field Methods -- with support from an Anne T. and Robert M. Bass Instructional Fellowship.
“He’s into pretty much everything and he still does his research, which is a complicated study and a pretty novel idea,” said his thesis advisor, Curtis Richardson, who calls Winton a Renaissance man. “He’s interested in all these aspects of life and the environment. He’s a world-class birder, he’s been extremely active in student activities and he’s a great teaching assistant—his students love him.”
After he finishes his PhD, Winton would like to continue to study wetlands, focusing on tropical wetlands. “Wetlands emit roughly a third of global methane and of that third, some 80 percent comes from the tropics,” he says. “So there’s a big need to better understand that source and there are few studies of tropical wetlands compared to temperate ones.”
And if he can work with tropical wetlands in a place where the birding is good, so much the better.