By Frances Figart, Creative Services Director
What’s that cute, fluffy animal with long ears hopping at top speed across the top of Clingmans Dome in Great Smoky Mountains National Park? Is it the common eastern cottontail, or could it be the rare Appalachian cottontail?
The Appalachian cottontail (Sylvilagus obscurus) is a charismatic high-elevation species of rabbit thought to be restricted to the Appalachian Mountains south of New York. As the scientific name suggests, it is not easy to see and is hard to distinguish from its cousin, the very similar eastern cottontail. In general, Appalachian cottontails have a thick, dark line around the edge of their slightly shorter ears and usually have a black spot between the ears, lacking the eastern cottontail’s white forehead spot or rust color between the ears.
Ph.D. research scientists Liesl Erb, JJ Apodaca, and Corinne Diggins can tell the two species apart by studying features of their skeletons and their DNA. They have spent part of the past three years learning more about this fascinating critter in a study sponsored by the North Carolina Wildlife Resources Commission and hosted in part by Great Smoky Mountains National Park.
“There was relatively little data on this species in the southern Appalachian Mountains prior to our study, including information on their distribution and habitat use in the region,” said Diggins, a research scientist with the Department of Fish and Wildlife Conservation at Virginia Tech in Blacksburg. “Because the Appalachian cottontail is a federal species of concern and a ‘knowledge gap species’ in North Carolina, the NC Wildlife Resources Commission was interested in determining baseline information on the species.”
The researchers used trapping and telemetry data as well as transects, counting pellet piles to determine habitat preferences. The Appalachian cottontail is generally thought of as preferring high-elevation, cold habitat, but the researchers found them in locations that were generally cool, though not necessarily the coldest spots, and in sites that were fairly wet year-round.
“In higher elevations, the rabbits selectively used heath balds and spruce-fir forest,” said Diggins. “In lower elevations, they selectively used habitats with significant pine and hemlock. Overall, they selected for certain habitat types and we found them at a wider range of elevations than we had previously thought.”
Erb, who is a professor of Conservation Biology at Warren Wilson College, focused on the distribution of the species and said there were four genetically distinct populations within the areas studied: Great Smoky Mountains, Roan Highlands, and Pisgah National Forest. Genetically, one of the biggest surprises the study revealed was the fact that hybridization occurs between Appalachian cottontails and eastern cottontails in these locations.
“Eastern cottontails occur at lower elevations in the southern Appalachians,” said Apodaca, the project’s geneticist and lead scientist with Tangled Bank Conservation. “But logging and habitat fragmentation over the last few centuries has potentially aided this species’ invasion into Appalachian cottontail habitat at higher elevations, which may contribute to instances of hybridization. Most hybrids seemed to be from male Appalachians mating with female easterns.”
According to Erb, future study will include “understanding the interactions between these two species, including differences in habitat use in areas where they both co-occur and the rates of hybridization. We also need to understand how habitat fragmentation influences the invasion of eastern cottontails into Appalachian cottontail habitat.”
Another big concern for ongoing research is learning how susceptible the Appalachian cottontail may be to the hemorrhagic virus that is impacting other cottontail species. While this fatal disease was thought to be only seen in domesticated rabbits, there was a recent outbreak in wild populations of cottontails in the Southwest.
This study laid the foundation, but more work needs to be done. Overall, the researchers feel that by providing baseline data on Appalachian cottontails, they are poised to make better recommendations for these rabbits’ continued management and conservation.
“Great Smoky Mountains National Park should be a place of sanctuary for rare species in the high elevations of the southern Appalachians,” said Paul E. Super, science coordinator at Great Smoky Mountains National Park’s Appalachian Highlands Science Learning Center. “Because of the difficulties in identifying this species in the field, we were not even certain a population of Appalachian cottontails remained in the Smokies. This study provides us with good news, not just confirming that these rabbits remain in the park, but also giving us a better understanding of what they need to continue to thrive here."
Image: Appalachian cottontail (Sylvilagus obscurus) by Edward Pivorun