Craig Rudolph’s white hair and a bushy white beard are a common sight in the longleaf pine savannah of East Texas. A U.S. Forest Service Southern Research Station biologist, Rudolph and his colleagues regularly check dozens of four-by-four-foot square box traps, and with more than 350,000 “trap-days” under their belt, they catch a lot of snakes. But though they are searching in the historic range of one of North America’s rarest reptiles, the Louisiana pine snakes, they’re catching fewer and fewer as the years pass.
Rudoph has been studying the Louisiana pine snake for more than fifteen years. His research indicates that there are only three small isolated populations in east Texas, in addition to three slightly larger populations in western Louisiana. “My gut tells me they’re in a world of hurt,” he says, though the snake is not yet listed as an endangered species.
Texas lists Louisiana pine snakes as a threatened species, which makes it illegal for people to collect, sell or harm them, but the status offers no habitat protection, and Louisiana law does not protect them at all. In 1999, the U.S. Fish & Wildlife Service identified the snake as a candidate species for listing as endangered or threatened, and though the agency has enough information to list them under the Endangered Species Act, it’s precluded by other higher priority species.
The robust tan-and-brown checkered Louisiana pine snakes grow to around six feet long. They live primarily in fire-adapted longleaf pine forests, an ecosystem that once stretched across the southeastern United States, from Virginia to eastern Texas. From the late 19th century on, timber companies logged prized longleaf pine, but replanted with faster growing loblolly. Only 3 percent of the original 90 million acres of longleaf pine savannah acreage remains, with less than 0.01 percent of the original old growth forest left.
The open park-like forests near Angelina National Forest’s Boykin Springs reveals a glimpse of what early pioneers saw before logging and years of fire suppression changed the face of the forest. Longleaf pines grow in nutrient-poor sandy soils, comprised largely of quartz crystals. The trees don’t achieve large girth for hundreds of years because they are essentially growing in glass. Knee-high grasses and plants carpet the forest floor. In centuries past, regular wildfires swept through the pine forests clearing out underbrush, but wildfire suppression drastically changed the character of these fire-adapted forests. Although the Forest Service now regularly ignites carefully controlled burns, biologists are just now coming to grips with how past mismanagement has affected the forest ecosystem.
Rudolph first got intrigued by the Louisiana pine snake in the early 1980s. He knew they were rare but he wondered why he didn’t often see them. “I spent a lot of time in what should have been good habitat,” he says. “I never saw one.” He and other scientists started researching the snake in 1993, and at that time, they didn’t know if the species was rare or just rarely seen, and they didn’t understand basic information such as what the snakes ate, what habitat they preferred, when they bred or how vulnerable they might be.
The biologists started trapping in areas they thought might be prime habitat—the remaining longleaf pine savannah—and they caught some right away. “We started doing a basic telemetry study,” Rudolph says. After catching a snake, they’d surgically implant a transmitter inside the snake’s body, and radio telemetry allowed them to follow the snakes’ movements and study their behavior.
“We did a lot of surveys throughout their historic range,” Rudolph says. Relatively quickly, they located three isolated populations in Texas—Boykin Springs on the Angelina National Forest, Foxhunter’s Hill in the Sabine National Forest, and Scrappin’ Valley on private timber company land. Then their luck ran out. “After the first few years, we never found any new populations.”
The radio tracking studies revealed one reason why the snakes had been so hard to spot—they live underground. “They spend most of their time in close association with pocket gopher burrows. It’s where they hibernate, where they shelter, and where they forage. And it’s how they escape from fire,” Rudolph says.
Although most people don’t give the world underneath the ground much thought, a subterranean ecosystem exists there. Pocket gophers create extensive burrow systems that provide shelter for dozens of species, from frogs to tortoises to salamanders to insects. The gophers eat roots and tubers, and, when necessary, try to escape from what Rudolph found was their most formidable predator, the Louisiana pine snake. The snakes play an important ecological role. They occasionally eat moles, turtle eggs and other small rodents, and as the subterranean-living reptiles slither underground, they keep abandoned gopher burrows open, which in turn provide habitat for other creatures.
This connection between Louisiana pine snakes and pocket gophers provided a major clue about the snakes’ decline. Wildfires once regularly scorched the forest, but decades of fire suppression caused an ecological domino effect. Pine forests became overgrown with brush and lost herbaceous groundcover, causing pocket gopher numbers to plummet, and in turn affecting Louisiana pine snakes. That situation remained until a court case in the late 1980s forced the Forest Service to better manage fire and controlled burns in national forests for endangered red-cockaded woodpeckers, which incidentally improved habitat for gophers and Louisiana pine snakes.
Although the Fish & Wildlife Service has not yet listed the Louisiana pine snake as endangered, they developed a Candidate Conservation Agreement, a collaborative effort that allows every impacted entity to help protect the species in the meantime. “The basic idea is to get different partners to do beneficial actions to reduce the threats and improve its conservation status,” explains Fish and Wildlife biologist Ben Thatcher. The Forest Service is also involved in a captive breeding program, though capturing enough snakes to breed has been challenging. They wanted to start the program with fifteen pairs; during the past year and a half they’ve caught just five males and one female. “At this rate it will take us thirty years to catch fifteen females,” Rudolph says.
Those concerned about the snake’s future must address serious issues before the species has any chance of recovering: drastic losses of historic longleaf pine forest habitat, decades of wildfire suppression, roadkills, fragmentation of remaining forest and the problems caused by the physical isolation of the handful of small populations from one another. And a new threat has arisen: timber companies managing longleaf pine forests in Louisiana, which have the largest populations of the snakes, have switched to intensive silviculture including herbicide to eliminate all groundcover. Removing fire once again from the forest does not bode well for the snakes or the ecosystem.
Louisiana pine snakes are rare under the best of conditions because of their biology – a female will lay around four eggs and it takes the snakes many years to reach maturity. Recovering one of the most imperiled snakes in North America will be no easy feat, whether it gets listed as a federally endangered species or not. “The biology of the species and its habitat management needs are reasonably well understood,” says Rudolph. “It is now a question of agencies, private landowners and biologists cooperating in the restoration of landscapes that can support the recovery of Louisiana Pine Snakes.”
Award-winning freelance writer Wendee Holtcamp writes about science and the environment from Houston for National Wildlife, Scientific American, Miller-McCune and other magazines.