Southern Hognose Snakes: Conservation for data-deficient species

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Adult Southern Hognose Snake – Houston Chandler

            As the days shorten and the nights get cooler, many species become more active, searching for mates, trying to find one last meal before winter, or moving into overwintering habitat. This includes the Southern Hognose Snake (Heterodon simus) that can occasionally be found crossing sandy roads on cool fall days. Inhabiting areas with xeric, well-drained soils, these snakes are rarely encountered outside of the spring and fall, spending the vast majority of their time underground. Southern Hognose Snakes can be recognized by their upturned snout and relatively stout-bodied appearance compared to other snake species of similar size (maximum length of around two feet). They can be distinguished from the closely related Eastern Hognose Snake (H. platirhinos) by the shape of the snout, distinct dorsal pattern, and light coloration on the underside of the tail. Southern Hognose Snakes specialize in feeding on toads (genus Scaphiopus and Anaxyrus), although they will occasionally eat other frogs or lizards. Very little is known about Southern Hognose Snake reproduction, and almost all of the available information comes from captive individuals. Captive clutches average approximately 10 eggs and are hypothesized to be laid in late spring or early summer (juveniles are often encountered in the fall). Other than this basic natural history information almost nothing is known about wild populations of Southern Hognose Snakes because their fossorial nature makes them essentially impossible to study with current methodologies.

Adult Melanistic Eastern Hognose Snake – Houston Chandler

            Southern Hognose Snakes are an extreme, but telling, example of one of the biggest challenges in conservation biology. How do we effectively conserve species that we know so little about? This issue plagues many conservation programs, limiting conservation biologist’s ability to understand complex ecological processes. Even for species like Eastern Indigo Snakes (Drymarchon couperi) that have been studied extensively over the last decade, there are still major knowledge gaps in the current understanding. For example, in Georgia, indigo snake observations come disproportionately from the winter months, making it difficult to clearly define habitat needs during other times of year.  In addition to knowledge gaps, long-term datasets are often needed to really understand how wild populations fluctuate through time, and the number of study years needed is directly proportional to an animal’s life span. Together these limits on the available data present real challenges to conservation.

            There are no easy solutions to data limitations, but I think that there are several areas where improvements could be made. First, a larger priority should be placed on research that aims to understand both species natural history and how species respond to environmental change. Too often funding agencies are chasing the next big thing in science, neglecting the vast gray areas that still surround a basic understanding of the natural world. Second, applying an ever expanding array of new technologies to conservation biology will allow researchers to collect data that would have previously been impossible. For example, tracking technologies have advanced by leaps and bounds in recent years. Lightweight transmitters can now transmit real-time GPS data on animal movements and be used on a wide variety of species. Technology will continue to advance and should be applied to conservation in creative ways. Third, and perhaps most importantly, emphasis should be placed on protecting and maintaining well-connected habitats that allow populations to persist with minimal influence from anthropogenic activity. We are unlikely to ever know everything about the ecology of any species and protecting habitat increases the likelihood of species persisting (although there are some contrary examples). This is already a major conservation goal in many cases but too often conserved properties act as islands in a human desert, with little chance for animals to move across the landscape. Fourth, any available data should be collected and reported for species that are rarely encountered in the wild. These data can be used by conservation biologists for many applications.

Juvenile Southern Hognose Snake from Florida – Houston Chandler

            We may never be able to fully understand the biology of Southern Hognose Snakes. At least not without being able to track animals reliably underground. Currently, the best recurring data that we have for this species comes in the form of opportunistic observations and occasional survey work. This October, we will be working with partners from the Longleaf Alliance to attempt to document unknown populations of Southern Hognose Snakes in Georgia. We will conduct road cruising surveys on and around several private properties with suitable soil characteristics that have not been surveyed previously. Documentation of existing populations is important for targeting future land protection and management efforts, which is especially important for populations on private properties. We are looking forward to spending some time looking for one of Georgia’s most elusive snakes!