MAYODAN — Most people tend to avoid bats. However, doing so now could mean the difference between survival and extinction for some of the species in North Carolina.
That’s why padlocked briefcases and meter-long acoustic recorders are sprinkled across the state’s parks. Han Li, a veteran mammalogist, is spending the summer studying these sites.
He’s researching bats, specifically bat sounds.
“This is the only type of study we can do this summer and for the foreseeable future because we cannot risk transmitting the coronavirus to bats,” Li said. “It is very likely the virus could be transmitted because there are so many infected people out there.”
With the number of confirmed cases rising in the state, mammalogists and wildlife experts are raising concerns and taking precautions against human-to-bat transmissions of COVID-19, which could be devastating to the already declining bat population in North Carolina.
While the Centers for Disease Control and Prevention has published research potentially linking the origin of COVID-19 to bats, North America’s bat population has been completely untouched by the pandemic, so far. Experts want to keep it that way.
A backdrop on bats
Over the past few years, white-nose syndrome, a fungal disease that affects hibernating bats, has cut North Carolina’s bat population nearly in half.
More than half of the 17 bat species in North Carolina are listed as “federally endangered,” “federally threatened,” “at risk” or a “species of special concern” by the North Carolina Wildlife Resources Commission (NCWRC).
With so many species at risk, the commission began issuing permits allowing rehabilitators to work with endangered bats for the first time this year. This previously was illegal because of the ability of bats to carry rabies.
But the COVID-19 pandemic has put all these efforts on pause.
“Our recommendation for now is that until we know more, rehabilitators should not take in any endangered bat species,” said Falyn Owens, an extension wildlife biologist with the NCWRC.
“We don’t know if our North American bats are susceptible to contracting the virus, and if they are, we don’t know the effect that might have on the bat population.”
This recommendation was issued to rehabilitators in mid-May and according to Owens could last until the pandemic ends, whenever that may be.
“When it comes to COVID-19, we really don’t know if there would be any impact at all,” Owens said. “But because white-nose syndrome has affected some of our bat populations so drastically, it’s not worth taking the risk that this virus could also have a negative impact.”
The risk is especially high since data published in the first Wildlife Diversity Program Quarterly Report of 2020 showed the state’s bat count increasing for the first time in nearly a decade.
“Results from winter bat surveys were more encouraging than they have been since the grim effects of (white-nose syndrome) began in 2012,” the report stated. “Hopefully these increases in hibernating bats become a widespread trend across western NC in the future.”
The commission’s recommendation only affects bats. Rehabilitators permitted to work with other rabies vector species, such as skunks, foxes, raccoons and bobcats can still do so.
In North Carolina there are approximately 480 active wildlife rehabilitators certified by the NCWRC, and less than 7% are licensed to work with bats.
“Since it hasn’t been allowed in the state before, we’re not sure how many bats would be affected by losing rehabilitation,” said Mary Frazer, co-chair of the North Carolina Bat Working Group. “It’s not common, but if a person came across an injured bat we would want to rehabilitate it, especially if it’s an endangered species. But now we can’t and it’s sad because we were really excited to have this change in regulation.”
The working group, which is made up of approximately 150 bat experts and enthusiasts, seeks to create a network of the studies being conducted in North Carolina.
“There are bat activities going on in different agencies in different regions,” Frazer said. “If we don’t get together to see who is doing what, it is difficult to put all of that information together to see what is happening with bat populations across the state.”
Li, who is also the state coordinator for the North American Bat Monitoring Program and a visiting professor at UNCG, is under contract by the NCWRC to conduct his research.
Most recently, Li was in Rockingham County setting up acoustic recording sites in Mayo River State Park — home to two of the nearly 80 sites he will be collecting data from this summer.
The sites record sound from sunset to sunrise and are specially built to record the high-frequency sounds bats use to communicate. According to Li, most N.C. bats communicate in frequencies ranging from 20 to 120 kilohertz — well beyond the human hearing range, which is only between 15 to 20 kilohertz.
The acoustic information allows Li to analyze flight patterns and estimate bat populations, which will be shared with agencies across the state.
By pausing any “capture and handle” studies, he hopes to minimize the chances of human-to-bat transmissions of COVID-19.
“There is no way we can allow another disease to spread that could potentially kill more bats,” Li said. “It is a risk we cannot take.”
According to Li, human-to-bat transmissions of COVID-19 could have just as much of a negative impact on humans. Especially if it creates a new strain of the virus that is eventually passed back to humans.
“It’s not that bats passing it back to us is the issue, the threat is a species in the middle — an intermediate host — that would eventually get to humans,” Li said. “The chance a bat gets so close to a human that it exchanges respiratory droplets is not likely, but it is likely that there is an animal in the middle. Perhaps some kind of food source, like a meat, that we eat.”
This exact fear made its way into pop culture through the 2011-film “Contagion.” Spoiler — the entire plot is based on a bat sharing a banana with a pig, which is later cooked by humans thus starting a global pandemic.
Despite the tough reputation, Frazer says bats play a critical role in North Carolina’s ecology.
“Bats in the Eastern U.S. are all insectivores. They provide an amazing service to farmers and all North Carolinians by eating insects,” Frazer said. “And besides the entomologists (who study insects), who doesn’t hate bugs?”