Invasive species can be native or exotic, plant or animal, but the common thread is their propensity to spread out of control at the expense of other organisms in the ecosystem.
South Carolina has a number of these creatures on its radar, but a few stand out as especially concerning.
Argentine Black and White Tegus
These large lizards can eat just about anything, according to Will Dillman, the chief of wildlife for the South Carolina Department. That’s a problem, especially for South Carolina’s ground nesting birds and egg-laying species.
Popular in the pet trade, the predators first became a concern in 2020 after they were reportedly popping up in a number of places around the state. Their high reproductive output makes them a tricky species to tackle, as demonstrated by states like Florida and Georgia, where the non-native species has already invaded.
“If they do get established and start reproducing here, getting ahead of them would be really, really difficult,” Dillman said. “The most effective time to intervene with a potentially invasive species is to prevent its introduction. With tegus, we know introductions are occurring, so then we’re trying to prevent it from getting established.”
South Carolina implemented new regulations earlier this year banning the Argentine black and white tegu from being brought into the state and requiring current tegu owners to register their pets with SCDNR.
Hogs have been around South Carolina for much longer than most people — the Spanish brought them over in the 1500s. However, the hog population that was once limited to coastal and floodplain regions has now spread to all 46 counties, including Richland County.
Hogs cause a number of environmental concerns. They compete with native species for resources, spread disease and cause damage to plants with their rooting behavior, which can erode soil and decrease water quality. Hogs can also be highly destructive to agricultural production and the economy, according to Charles Ruth, a wildlife biologist and the big game program coordinator with SCDNR.
“It’s just a never-ending list of potential bad outcomes when you have these feral pigs,” Ruth said.
People are contributing to the problem, according to Ruth, by catching the hogs in one part of the state and releasing them in another. To curb the spread, South Carolina recently passed a bill requiring special identification for hogs being transported on public roadways or waterways.
Originally from China, cogongrass has already established itself across much of the Southeast. Now, South Carolina is seeing patches appear within its own borders.
“It chokes out everything else within where it’s growing,” said David Coyle, an assistant professor at Clemson University who focuses on forest health and invasive species. “It’s fire-tolerant. It’s tolerant of basically every condition, and it takes multiple years of treatment to get rid of it.”
No natural enemies compete with or benefit from the presence of cogongrass, and it can grow in both forested and open areas. Taken together, all of these factors make for an especially pesky invader.
The Lowcountry has seen the most cases so far, and while Coyle said the grass is not yet widely problematic here in the Palmetto State, it is being monitored very closely to ensure it doesn’t lay down too many roots.
To combat the issue, the Clemson Department of Plant Industry sends a member from its team to investigate suspected cases and provide treatment.