Repatriation of eastern indigo snakes to conservation lands in South Alabama, USA

Summary

The eastern indigo snake (Drymarchon couperi), federally listed as Threatened and now confined in the wild to Georgia and Florida, was targeted for repatriation to Alabama's Conecuh National Forest by a consortium including Auburn University, The Orianne Society, Zoo Atlanta, and state and federal wildlife agencies, building on a 1990s effort that failed to establish any of 36 release sites. The 10-year project limited removal to two gravid females per source population annually, retaining them only until they laid eggs before returning them to the wild; Zoo Atlanta raised the resulting offspring for two growth years before a final acclimation period in outdoor pens at Auburn, then released cohorts of about 20 radio-tagged snakes each spring from 2010 to 2012 using both hard and soft release methods, with a goal of releasing a minimum of 300 one to two year olds. Radio-tracked snakes used xeric longleaf pine sandhills and gopher tortoise burrows in patterns matching published data from source-area wild populations, and survival did not differ between release methods, though soft-released males retained smaller home ranges near the release site with greater overlap with females. Two females captured in 2012 laid eggs producing nine wild-hatched offspring, though no unmarked (naturally recruited) individuals have yet been found. Difficulties included a novel Fusarium fungal disease in captivity, pen escapes through burrows, and unavoidable road mortality. The project rates itself Successful, citing home range and habitat use closely matching source populations.