C.J., a 7-year-old chocolate Lab, has a nose for more than indigo snakes. He has sniffed for spider monkeys in Nicaragua, big cats in Brazil and bats in New Mexico.
The intent is to determine what is leading to the decline of the threatened species and to take an informal census on the snakes in the swamp, said Sara Aicher, a refuge wildlife biologist.
"We know we have some, but we don't know how many," Aicher said.
Refuge officials made arrangements to use C.J.'s talents Monday and Tuesday through Project Orianne, a wildlife conservation organization based in Clayton that is dedicated to saving the species.
Aicher said a snake survey has never been conducted in the area searched on the east side of the refuge, nor has a dog been used to track the elusive reptiles inside the refuge.
"We have not had a good survey of indigo snakes," Aicher said. "It will help us compare our management practices."
Indigo snakes were once common throughout Florida, South Georgia and parts of Mississippi and Alabama, but their numbers have dwindled. Their current range is in south Georgia and parts of Florida, including a few isolated populations in the Panhandle.
The nonvenomous snakes are considered the longest snakes native to the United States, sometimes reaching lengths greater than 8 feet, according to refuge biologists.
C.J., who was rescued from a shelter, is trained to track different animals, including individual species of snakes, without confusion, said Kara Ravenscroft, C.J.'s handler.
Ravenscroft, her husband, Mike Ravenscroft, a field technician for Project Orianne, and the team of researchers allow the dog to take the lead during their search. Because indigo snakes often share burrows with gopher tortoises, the search focused on upland areas at or near the refuge.
A bell attached to C.J.'s collar makes it easier to follow him as he sniffs across the rugged terrain, through thick bushes and over piles of branches.
Mike Ravenscroft said the dog leads them miles during a typical search, but the distance depends on the terrain.
"It's rough habitat here," he said.
Whenever the dog found a tortoise burrow, he intently sniffed the area, trying to pick up the scent of an indigo snake. C.J. even stuck his head deep into some of the burrows.
The dog's sense of smell is good enough to lead searchers to snake droppings and skin that has been shed.
"You can tell by the change in his behavior," Kara Ravenscroft said of the dog's wagging tail when he discovered the scent of a snake.
Mike Ravenscroft said the hope is to find areas where the snakes congregate during breeding season, which begins when cooler weather arrives.
Searchers planned to tag some snakes and remove a few scales for genetic tests, Aicher said, but C.J. found only one snake and two "sheds" - skin from snakes that had molted.
The results were disappointing because they may not have been looking in the correct area during the two-day search, Aicher said.
"They're just really difficult to find because they are so scattered," she said. "We'd love to find more, but it's not surprising."
Aicher said it's possible some snakes could be relocated from areas where they are known to be thriving, such as north of Fort Stewart and Telfair County.