Jan/Feb 2008State Parks: Outdoor Laboratories by Elizabeth Renedo

South Carolina's State Parks have value beyond measure, as recreational destinations, as natural places and even as laboratories for researchers from around the world.

Ask most South Carolinians about our state parks, and they'll likely recount happy memories of fun family gatherings, camping adventures, great parks programs and days spent simply enjoying the pleasures of nature. Most Palmetto State residents and visitors who spend time in these treasured natural areas have no trouble listing the parks' attractions and the positive impacts they have on surrounding communities, but many park visitors may not even know about one of the most fascinating roles state parks play: the role of outdoor laboratory.

Each year, researchers from the Palmetto State and beyond take to the parks - after applying for and receiving a permit to do so from the State Park Service - gathering the data they need to answer their conservation questions. State parks may not be outfitted with cutting-edge laboratory facilities, but they have something even rarer that many researchers need: large, well-preserved natural spaces in which to observe wildlife, plants and other natural features in their natural environments. They also receive the support of park staff who have the advantage of knowing the parks' wild spaces like no one else.

Clemson University timber rattlesnake researcher Jeff Mohr touts the support he receives from Park Ranger Scott Stegenga at Table Rock State Park as one of the best parts of conducting his research there. "Scott has been very helpful - he's even caught some of my research animals for me," he says. This support is especially valuable to Mohr, whose subjects are particularly difficult to find.

Mohr explains what makes finding South Carolina's timber rattlers such a challenge: "They don't den together in the winters here like they do in other areas." Throughout most of their range, timber rattlers spend their winters holed up in a den with other timber rattlesnakes that live in the same area. This is ideal for researchers who can locate these dens and wait for the snakes to emerge in the spring, then collect research specimens while the sluggish snakes sun themselves before returning to their spring and summer home ranges.

The unusual denning habits of South Carolina timber rattlers represent just one bit of information Mohr has already discovered in only his first year of a three-year research project. "We just don't know anything about them, what they do, whether the population is healthy or in need of protection," he says. Mohr gathers this baseline information using radio telemetry, which involves surgically implanting small transmitters under the ribs of his slithering subjects, then releasing them and tracking their movements with a radio receiver.

It is Mohr's hope that his research will benefit Table Rock's timber rattlesnakes, which suffer most at the hands of park visitors, their biggest predators. "Eventually, we'll be able to use this information to help the Park Service plan to build facilities in places where timber rattlesnakes won't be disturbed," he says. Until then, Mohr encourages park visitors to leave timber rattlesnakes alone if they are fortunate enough to encounter the big, beautiful, docile reptiles. "These snakes are very non-aggressive; they rarely even rattle. They mainly rely on their camouflage for protection, so they don't hang out in open spaces like trails and campsites. They don't really pose a threat to park visitors."

Another researcher who has hopes that his work will benefit the state parks that serve as his laboratories is Jim Hanula, a research entomologist with the USDA Forest Service in Athens, Georgia. Dr. Hanula chose Hunting Island and Lake Warren state parks as his laboratories to study laurel wilt, a complicated disease that has killed many redbay trees in both locations.

What makes the disease complicated? First, the beetle that spreads the disease-causing fungus is an invasive exotic species from Asia first detected in Port Wentworth, Georgia in 2002. By 2003 - mere months later - the South Carolina Forestry Commission reported significant redbay tree mortality on Hilton Head Island, which proved to be caused by the laurel wilt fungus. Second, the fungus is spread in an unusual, almost science-fiction-like way. According to Hanula, "redbay ambrosia beetles carry the laurel wilt fungus in a special structure in their heads." It gets even stranger. When the beetle is ready to reproduce, it bores into a tree trunk to form a chamber where the young will live. As it bores in, the fungus spores stored in the head are released and the fungus grows on the walls of the chamber to provide food for the young beetles.

The goal of Hanula's research is to find out what time of year the redbay ambrosia beetles are most plentiful and active in the Palmetto State and what it is about redbay trees that the beetles find so attractive. Understanding the beetles' "seasonal biology" and developing a chemical lure to catch beetles will help researchers develop more effective methods to control the pests.

Hanula suggests a way park visitors can help support his, and the parks', mission to prevent the further spread of laurel wilt: "Do not take firewood from one park to another and don't move any wood between parks or campsites." He cautions that many campers are tempted to cut down the obviously dead redbay trees and use them for firewood, often carrying the same firewood supply on multiple camping trips to multiple destinations. Campers should resist temptation, however, because this risky behavior can spread laurel wilt to other areas.

Also conducting her research at Hunting Island State Park, Diana Bierschenk, a student at the University of Exeter in Cornwall, England pursuing a Master of Science degree in conservation and biodiversity, studies sex ratios in loggerhead sea turtle nests. "Sea turtles are a great study subject in conservation because they are affected by so many things found on land, in the shallows, near coral reefs and in the open ocean," says Bierschenk.

Just as studying adult loggerhead sea turtles can tell researchers a lot about the environment in which the turtles live, studying sex ratios of the young that hatch from nests can provide more information than meets the eye. Because the sex of a loggerhead sea turtle is determined by the temperature of its egg in the nest, Bierschenk says, "understanding current trends in sex ratio will help us predict how sex ratio might be affected with increasing global temperatures caused by climate change." The current trend is, simply put, loggerhead sea turtle populations, particularly those in the warmer southern part of their range, are increasingly female-biased because higher nest temperatures produce more female turtles. In South Carolina, which falls in the loggerhead's northern range, the bias toward female young is not as strong, making our coast and those of North Carolina and Virginia very important for producing male loggerheads.

Bierschenk chose her research sites based on the number of loggerhead nests they typically host, and Hunting Island was an ideal location. "The parks usually have good numbers of turtles because they are more protected than the surrounding towns from harmful effects such as light pollution," she says. And, of course, it's "absolutely beautiful" and staffed by "very friendly and helpful" folks, adding to its attraction. Bierschenk has a few tips for those who visit coastal state parks during loggerhead nesting season. First, do your part to keep the beaches clean - trash left on the beach might be washed into the ocean and turtles could mistake it for food, which can be harmful. Turn off lights at night to avoid distracting females and young turtles coming and going from the ocean. Finally - this one's especially important for young park visitors - be sure to knock down sand castles and refill holes in the sand to keep turtles from getting stuck or being discouraged from coming up on the beach.

Whatever they study, whichever park they study it in, scientists who do research in state parks have a real appreciation for the parks and their important roles in conservation, from preserving unusual ecosystems to instilling an appreciation of nature in those who visit and even providing a laboratory for interesting and important conservation projects.

Elizabeth Renedo was a former managing editor of South Carolina Wildlife magazine.