Update:"Dr. Francisco Piedrahita was located by a Jefferson Parish Sheriff's Office helicopter, standing under a tree with a camera around his neck, about 200 yards off the Wood Duck trail.
The helicopter alerted ground crews, which then located Piedrahita, who said he survived by eating foliage and dipping swamp water.
Linda Friar, a spokesperson for the National Park Service said Piedrahita appeared to be in good condition, but was dehydrated. He was taken to West Jefferson Hospital where officials said he was "covered in bug bites and his legs were blackened from standing in swamp water for so long." They said otherwise he was okay."
As someone who has spent a bit of time on the swamp, "eating foliage" means he had some knowledge of the local flora or was darn lucky. "Dipping swamp water", too. There's some nasties in that water besides 'gaters and snakes.