Warnell alumna launches project to help southeastern snakes 

A graduate student at the University of Georgia is trying to understand how a fungal disease is affecting the health of snakes across the southeastern United States. 

Corinna Hazelrig, a recent graduate of the Warnell School of Forestry and Natural Resources who is now a DVM-PhD student in the College of Veterinary Medicine, is monitoring snakes at three locations in the Southeast to gain a better understanding of how pathogens are affecting terrestrial and semi-aquatic snake populations. The project connects her work as a pre-veterinary wildlife sciences student with her graduate studies. 

The pathogen that causes snake fungal disease is not picky–it affects all types of snakes. But what’s interesting is that some snakes have more severe experiences with the disease, while others don’t exhibit symptoms. In some cases, the disease is fatal.  

"A pathogen is a disease-causing agent, and so we sometimes see snakes that test positive for the causative agent of snake fungal disease that don't elicit any symptoms," said Hazelrig.

Symptoms of the disease include skin abnormalities like scales, crusts and in more severe cases, ulcers. A snake experiencing symptoms could be battling other infections at the same time, undergoing what’s called a co-infection. Hazelrig said she wants to know how these co-infections could alter the severity of snake fungal disease.  

Her research will address three important questions:  

• Are certain snake species more susceptible to developing snake fungal disease than other species? 
• How do co-infections with other pathogens affect the severity of the disease?  
• How do co-infections with other pathogens affect the death rate of the disease?  

Hazelrig said finding answers to these questions will be pivotal to snake conservation in the Southeast.  

“An objective of our study is to further understand risk factors associated with disease presentation to try to elucidate why we observe asymptomatic snakes, minor infections, severe infections, and fatality to better inform snake conservation management strategies,” she said.  

This is a passion project for Hazelrig, who organized a fundraiser through the Wildlife Disease Association to help alleviate travel and material expenses. The project builds off the One Health lessons Hazelrig received as a Warnell undergraduate student.  

One Health is an interdisciplinary framework that incorporates the relationship between human, animal and ecosystems. In One Health, professionals work collaboratively to find solutions that help people, animals and the environment achieve better health outcomes. 

It’s also a concept taught in several of Warnell’s wildlife sciences classes. 

“I became interested in snake and wildlife disease research through my passion for conservation, herpetofauna and veterinary medicine,” she said. “As a young researcher, I asked myself how can I combine my passion and the route became evident through One Health and wildlife diseases.”  

Hazelrig plans to complete the project in the summer of 2024. She is focusing on four types of free-ranging snakes, which are abundant in the Southeast and have a known history with snake fungal disease: the terrestrial black racer and eastern rat snake, and the semi-aquatic common garter snake and snakes in the Nerodia genus. 

“My goal was having two focal species that are terrestrial and two that are semi-aquatic to try and compare disease prevalence between snakes of different natural histories," she said.  

The snakes are assessed at three different study sites across the Southeast: Whitehall Forest on the UGA campus in Athens, Georgia; the Savannah National Wildlife Refuge in Southeast Georgia and South Carolina; and Lake Woodruff National Wildlife Refuge in Central Florida. Hazelrig has been traveling to these sites every month to collect swabs, blood and fecal samples and to tag snakes for identification purposes. She encounters anywhere from 4 to 13 snakes when visiting each location.  

The pathogen that causes snake fungal disease is not zoonotic, meaning that it can't spread to humans. But Hazelrig is concerned about how it will affect snake populations that may be more susceptible to disease. Factors like inbreeding, habitat loss and fragmentation and climate change put populations more at risk.  

"Studies have shown great declines or local population extinctions because of this fungus," she said. "So typically, when we see populations that have been separated or fragmented, we see the fungus as being the last straw that breaks the camel's back."   

The loss of any snake is troubling—they provide a variety of ecosystem services, said Hazelrig. Not only do they control small wildlife populations like rodents, but they also help prevent the spread of other diseases. “By acting as a predator to more diseased animals or tick-infested animals, they are removing hosts from our ecosystems that could potentially be a reservoir for a zoonotic pathogen or a pathogen that may impact other wildlife species that are important for conservation," she added.  

To prevent the disease from spreading throughout the Southeast, Hazelrig encourages recreational hikers to disinfect their equipment, if possible. "It’s highly predicted that snake fungal disease was introduced through the pet trade," she said. "And so, humans most definitely have an effect on the movement of pathogens that impact amphibians and reptiles." 

By understanding how the fungal disease is affecting snakes both on land and water, she said, we can be better prepared to protect them in the future.  

"The snake fungal research is trying to understand which species may be more at risk and how to manage those, because snakes are really important for our ecosystems," said Hazelrig.