Only time will tell whether the Louisiana pine snake can be sustainably restored to longleaf pine ecosystems in its native range.
Researchers implanted each of the snakes released on May 1 with a passive integrated transponder (PIT) that allows them to be tracked by recorders installed on the site. "So far we've not had much success with the recorders, which are dug into the ground in four places on the release site," says Rudolph. "We've recorded activity in the first weeks, but nothing later on. This is not unexpected, since these snakes have a large home range and probably leave the immediate area. We need to get good population estimates for the areas we've released in, but the only way to get data is by trapping, which is very time-consuming and expensive."
The animal's biology presents another constraint to its survival. While most other snakes produce large clutches of eggs, the Louisiana pine snake lays only three to five eggs, and in captive breeding programs, sometimes only one or two eggs per clutch hatch. This low reproductive rate means that the species might not recover quickly in the wild. Rudolph worries that breeding programs, which rely on the progeny of only 16 founder individuals caught in the wild, may be producing snakes that are not genetically diverse enough to survive when released.
"In the best-case scenario, there would still be Louisiana pine snakes out there that we've never caught that can breed with the released snakes," says Rudolph. "We have traps operating for thousands of trap days a year in Texas, for instance, and haven't caught a single snake in three years. When we find better ways to monitor our releases, perhaps we'll find some additional populations."
|Contact: Craig Rudolph|
USDA Forest Service ‑ Southern Research Station