Seasonal Habitat and Shelter Selection by Reintroduced Eastern Indigo Snakes in Conecuh National Forest, Alabama

Abstract

Species reintroduction has become an increasingly popular conservation method for reestablishing extirpated populations of declining species. Because poor habitat quality at release sites has been one of the most frequently reported reasons for failure of reintroductions, evaluating habitats selected by reintroduced animals is of paramount importance. I radio-tracked 38 Eastern Indigo Snakes reintroduced to Conecuh National Forest, Alabama. My study objectives were to: 1) quantify habitat and shelter selection at multiple spatial and temporal scales, 2) compare results from my study to the results of a study of a wild population near the source sites, 3) evaluate whether hierarchical habitat selection occurred in reintroduced snakes, and 4) inform future management of habitat at the release site. My results document that habitat selection in reintroduced snakes occurred at multiple spatial and temporal scales. At a landscape scale, snakes selected fields and roads and mixed pine-hardwood habitats significantly more than wetlands and hardwoods. Habitat selection at a home range scale was not significant overall, although open canopy longleaf pine forest was selected significantly more than mixed pine-hardwood forest. However, when seasons were examined separately, significant differences emerged at the home range scale. During the spring, summer, and fall months, snakes selected open canopy longleaf pine forests significantly more than fields and roads or mixed pine-hardwood habitats. During winter months, snakes selected fields and roads significantly more than wetlands and hardwood or mixed pine-hardwood habitats. Among sites used as shelters, gopher tortoise burrows ranked highest, followed by stump/root in both non-winter and winter seasons. Snakes in my study used habitats and shelters in a manner similar to that of snakes studied previously in Georgia near the source sites of my snakes. Selection was strongest at shelter and landscape scales when compared to home range scale and, therefore, I conclude that habitat selection by reintroduced snakes in my study was not hierarchical. My observations indicate that maintenance of high quality gopher tortoise habitat, including prescribed burning to maintain open-canopied habitats, will be critical for the successful reestablishment of Eastern Indigo Snake populations in the northern part of its range.