COVID-19 isn’t the only contagious disease sweeping across American shores. Earlier this year, the team at the Southeastern Cooperative Wildlife Disease Study (SCWDS) in UGA’s College of Veterinary Medicine confirmed the first cases of a highly pathogenic avian influenza virus in three bald eagles in Georgia. The news set off alarm bells in the Georgia wildlife community.
“It’s an unprecedented outbreak,” said Nicole Nemeth, associate professor in the College of Veterinary Medicine and head of the wildlife research and diagnostic service at SCWDS. “Sometimes influenza virus comes in with migrating birds and then dissipates. This outbreak is making us nervous.”
Often referred to as HPAI, the virus has killed thousands of wild birds in more than 50 countries and shows no signs of stopping. Birds of prey have been hit hard, with HPAI a likely factor in decreased nesting success among Georgia’s coastal bald eagles.
Domestic poultry have been affected, too, with millions of chickens across the United States depopulated to curtail the virus’s spread. HPAI has also been detected in foxes, skunks, marine mammals, and bears. It’s an unsettling scenario, even for experts accustomed to receiving and delivering grim news.
Former SCWDS director David Stallknecht says the program serves a vital epidemiological role for the health of both animals and humans, since many pathogens they monitor can jump from species to species.
“I’m worried,” said David Stallknecht, professor in the College of Veterinary Medicine and former director of SCWDS. “These viruses find their way into naïve populations in a manner similar to how COVID entered the human population, and that doesn’t go well. We don’t yet know if there will be long-term impacts on wildlife populations.”
While the deaths of nesting eagles might prompt some to look the other way, the SCWDS team has kept vigil, helping state agencies and wildlife groups understand how the virus is changing and evolving. That’s their job—and the passion that drives them.
“Our ability to help is by learning as much as we can,” said Rebecca Poulson, assistant research scientist with SCWDS.
Disease detection for 65 years and counting
SCWDS has been in the forefront of disease detection and surveillance since 1957, when it was founded by the Southeastern Association of Fish and Wildlife Agencies to determine why white-tailed deer were dying in large numbers. SCWDS’s first scientists successfully identified a hemorrhagic viral disease as the cause of that die-off. They forged an agreement with UGA’s College of Veterinary Medicine to establish a headquarters in Athens, and research expanded to include wildlife species across the southeastern United States.
Today a partnership of 17 member states and led by 8 core faculty members, SCWDS is tasked with investigating wildlife diseases and providing expertise to federal and state agencies on wildlife health, domestic livestock interests, and human health. SCWDS experts lead with diagnostics and surveillance while simultaneously raising public awareness. Their message? Animal, human, and environmental health are inseparable—and individual actions on behalf of wildlife matter more than we might think.
“Everyone is a steward,” said Mark Ruder, associate professor in the Department of Population Health and the director of SCWDS. “Some people just don’t know it yet.”
In the news, behind the scenes
Diagnosing HPAI in bald eagles wasn’t the first time the team’s findings have made headlines. In recent years SCWDS researchers have received attention for their engagement on a range of cases: mysteriously dead crows, deer with hairy eyeballs, and rabid black bears, to name just a few.
Some of these are rare events, curiosities that attract temporary interest and then fade from view. Other times, cases don’t garner as many headlines yet pose a greater threat to ecosystem health in the long run.
Take influenza A viruses in migrating waterfowl and shorebirds. Poulson has been studying the pathways of these common viruses in waterfowl and shorebirds throughout North America. While scientists have long known about low-pathogenic flu viruses, Poulson’s investigations revealed that they can survive outside their hosts and stay infectious far longer than once estimated—up to seven months.
“We’re looking at how these viruses move with wild birds as they migrate,” she said. “Shorebirds are especially concerning because of their conservation status. We need to learn more.”
Behind the scenes, SCWDS is also tracking chronic wasting disease (CWD) in cervids, a fatal neurological condition affecting white-tailed deer and other deer species. Like mad cow disease, the illness is spread by pathogenic proteins that can cause symptoms mimicking dementia. Although CWD has occurred in the United States since the 1960s, the disease’s spread is causing concern. With Alabama, Tennessee, and North Carolina all seeing recent cases, Georgia wildlife experts are bracing themselves. SCWDS is tracking transmission pathways, supporting Georgia’s Department of Natural Resources and other first responders as they try to prevent the disease from crossing into the state.
“We really lean on public engagement here,” said Ruder. “We rely on the public to see and report sick deer.” Private citizens should call their state wildlife agency to report sick or dying wildlife for submission to SCWDS.
From service to research and back again
Research forms an integral part of SCWDS’s mission, and the support activities the team carries out in the field both shape and are shaped by individual faculty interests.
Nemeth’s scholarship offers one example. Her work explores the potential role of disease in the decline in wild turkeys across the Southeast. These turkeys, once game staples, have experienced marked population decreases over the past 10 to 20 years. Along with other faculty at SCWDS, Nemeth has assessed the susceptibility of wild turkeys to West Nile virus infection and studied lymphoproliferative disease virus (LPDV) as another potential contributor to the birds’ decline. LPDV is a tumor-causing virus first documented by SCWDS in 2009. Recent grants from the National Wild Turkey Federation and the Association of Fish and Wildlife Agencies’ multistate conservation grant program will allow Nemeth, several other SCWDS faculty members, and Warnell faculty member Michael Chamberlain to further examine LPDV and other diseases of wild turkeys.
“We need to answer these questions to conserve turkeys as an important gamebird,” Nemeth said. “We need more information at the cellular level to understand the potential impacts of disease.”
Michael Yabsley’s research interests include sarcoptic mange in black bears. Though the “itch mite” has been detected in bears, foxes, and coyotes for 20 years, recently the disease has worsened, explained Yabsley, professor of wildlife disease and a diagnostic parasitologist for SCWDS. Mange is now affecting bear populations in more states, including the first case found in Georgia last year.
“These bears look really bad,” he said. “They’re naked and skinny and suffering. It’s caused significant public outcry. People are demanding action, but state agencies don’t always have a lot of options.”
Yabsley and UGA colleagues are working to understand why the mange is becoming so severe. They are also conducting a study of human emotions surrounding mange and wildlife, partnering with faculty in the Warnell School of Forestry and Natural Resources to examine the human dimensions of conservation efforts.
Chris Cleveland, assistant professor in the College of Veterinary Medicine and a SCWDS scientist, began his research career studying the resurgence of guinea worm in domestic dogs. He worked with Yabsley and experts at The Carter Center to study the parasite’s transmission in Chad and subsequently developed clinical field trials for dogs infected with the parasite, including a pharmacokinetic study of a novel treatment for dogs.
More recently, support from the USDA is allowing Yabsley, Cleveland, and Ruder to study the Asian longhorn tick, first recognized in New Jersey in 2017. They have conducted surveillance to assess the importance of wildlife hosts, habitats, and microclimate variables on the tick’s presence and abundance in a Virginia county. In an era of climate change, time is of the essence to understand what kind of threat this tick poses for humans. The number of pathogens carried by this tick is increasing annually.
“A single tick can churn out a whole new population,” said Ruder. “When you think about invasive species, that’s about as good—or as bad—as it gets: you only need one.”
Training for change
Mentoring and equipping the next generation comprises a key part of these research efforts. SCWDS faculty offer educational workshops and programs for wildlife biologists and veterinarians; they also train diagnosticians, graduate students, and pathology residents. Students have the chance to engage in hands-on field work at every step of the research. Cleveland, for example, works with his students on regional surveillance for a zoonotic tapeworm (Echinococcus) found in coyotes and other wild canids.
“Being out in the field, experiencing different perspectives, it’s so important for learning,” he said. “Whether you’re talking to local hunters, state biologists, or even a tribal chief in Chad, all those conversations should inform how we frame our research questions.”
Sonia Hernandez, professor of wildlife disease in a shared position between SCWDS and the Warnell School of Forestry and Natural Resources, brings students into her studies of how anthropogenic activities affect wildlife ecology and health. Since 2009, she has studied the American white ibis and its adaptation to urban life. Florida has destroyed about half of its natural wetlands, and ibises are attracted to cities because people feed them. Hernandez and her students explore how foraging and living in the city changes these birds’ movement patterns and health, with a particular focus on Salmonella. They have found that ibises in cities have more Salmonella than those in natural areas. They were also the first to describe that West Nile virus can kill white ibis nestlings, a link that had not been known until she and team members conducted a key study.
“There are so many changes that we humans are imposing on the environment—and those changes come with important impacts on pathogen and disease dynamics,” Hernandez said. “It’s a wonderful time for someone who wants to try to disentangle some of these effects —with evidence-based research—hopefully to make some sound management recommendations that will keep wildlife and people healthy.”
“Everyone is a steward [of wildlife health]. Some people just don’t know it yet.” –Mark Ruder, associate professor of population health in the College of Veterinary Medicine and director of the Southeastern Cooperative Wildlife Disease Study, leaning into the cooperative nature of the project’s mission.
Realism and hope
It takes a special type of person to enter and embrace a career in wildlife disease research. “We have faculty and staff who have been here a long time,” said Poulson. “They’ve devoted their lives to this work. Some days are hard, but we can lean into the support of the team. We’re small but mighty!”
Nemeth chose the field because she loves wildlife and saw the need to contribute to their conservation. One of her recent studies tracks the pathways of anticoagulant rodenticides—rat poison—in bald and golden eagles, information critical to informing regulations surrounding exposure risk. A bird who eats a poisoned rat can also experience fatal poisoning, she explained. “As long as I can see wildlife out there fighting to live, I’ll keep fighting for them,” she said. “That gives me hope. They’re still out there. They’re trying to adapt to our changing world.”
Engaging in research that daily confronts the realities facing imperiled wildlife isn’t easy. But doom and gloom is not how the SCWDS team tells this story.
“I do this work because it’s incredibly interesting,” Stallknecht said. “Wildlife health is all related to our individual actions, one way or another. There are steps we can take. Tiny steps add up.” He gave an example: “When I build a house, I destroy wildlife habitat. What should I do? Maybe build a smaller house. Stop and think about our collective impact and our individual impact. Ask yourself: What difference am I going to make?”
Having partnerships helps. SCWDS scientists have crossed cultural, political, and geographical divides to find common ground with individuals who share a deep commitment to wildlife conservation. That’s a significant—and lasting—achievement. “There are things we can do,” said Ruder. “Think about habitat conservation, for example. We can pull together to enable the wildlife population to be more resilient and withstand the impact of these diseases.”
Poulson takes the message of hope one step further. “I would tell people to go outside and enjoy this incredible wild world,” she said. “The more we can get out there and understand this world, the more we can care for it. Everyone is on their cell phones all the time, not looking up, not engaging in nature. That doesn’t help. We need to put our phones down and get outdoors. We need to pay attention.”
It’s a mission worth going to the woods for.
[To read the complete article that includes photos and links, please see The UGA Research Magazine here.]