Rattlesnakes in the Southern Highlands



Rattlesnakes in Southern Highlands

Authored by Chris Jenkins

My day started early sitting on my porch, coffee in hand, looking across the valley at the mountains that only an hour from now I would be trekking through searching for one of the greatest icons of the southern highlands. As I drive my truck miles up a rough forest service dirt road, the GPS reads about 2,800 feet in elevation. I know that to reach my goal of finding gestating female Timber Rattlesnakes, I will climb on foot to over 4,000 feet into the Southern Nantahala Wilderness. I start up the trail counting the various lizard and newts I see along the way. By the time I make the ridge line, all of my clothing is soaked through with sweat, and I leave the trail to begin bushwhacking my way towards the first gestation site of the day.

Rattlesnakes in Southern Highlands

As I approach, the canopy gives way to bare exposed granite, strewn with boulders. I approach the gestation site and peer over to the other side to see a loop of a gravid female’s body. Backing away slowly, I make a large circle and approach from below. My reward is an incredible view of a large yellow-phase Timber Rattlesnake, swollen with the eggs she cares for inside her body. Instantly, all of the incredible aspects of this snake’s biology are running through my head, thinking about how many years she needed to forage to get the energy for this pregnancy; how these snakes have evolved to keep their eggs inside their bodies to control their temperature before giving birth to live young; how in just a month, she will give birth and spend the next week or two caring for her young at this exact spot. Then I suddenly realize where I am. Turning to the horizon, I can see for miles, mountains folding unto mountains as far as the eye can see.

Rattlesnakes in Southern Highlands

Some of my greatest passions in this world are rattlesnakes, mountains and wild places. While many people might be just as happy to see a snake crossing a road, it gets me excited to see a rattlesnake and realize I am miles from the nearest road. Living and working in the southern Blue Ridge Mountains of Georgia and North Carolina, I have the chance to experience Timber Rattlesnakes living in some of the most mountainous and remote country possible. I am excited to see a Timber Rattlesnake in any situation, but to have the opportunity to work with them in some of the most remote places in eastern North America is a unique experience.

Timber Rattlesnakes are found throughout much of eastern North America, historically ranging as far as Maine, Florida, Minnesota and Kansas. But Timber Rattlesnakes have been declining through most of their range for many years. They are now thought to be locally extinct in places like Ontario, Maine and Rhode Island, and there are multiple northeastern and northern midwestern states were only a handful of populations remain. Timber Rattlesnakes are listed as Threatened or Endangered in many states such as Vermont, Minnesota and Texas, and in many states there are active programs working to research and conserve them. However, there are also many states where the Timbers are declining that have not given the snake any form of protected status.

Timber Rattlesnakes are arguably one of the most extensively studied snakes in the world, and in certain parts of their range, we know quite a bit about their biology. However, the southern Blue Ridge Mountains of western North Carolina, eastern Tennessee and northern Georgia is one of the places where we know relatively little about their biology. Of course, many aspects of their ecology will be similar across the range, but certain aspects will be much different. For example, in the southern Blue Ridge they likely reach their highest elevations and live in some of the most mountainous terrain in their range. These extreme mountainous landscape undoubtedly affect how they move, select habitat and forage. In addition, winter temperatures are also higher than many northern sights, and thus their overwintering ecology is likely very different. In the southern Blue Ridge, we rarely see the large overwintering aggregations that characterize many northern populations. The southern Blue Ridge also has many more fire adapted habitats than many northern sites which undoubtedly influence the snake’s habitats.

In an effort to learn more about southern Blue Ridge Timber Rattlesnake populations, we have launched an inventory and monitoring program under our Appalachian Highlands Initiative. Over the past three years we have inventoried areas in North Georgia and Western North Carolina for female gestation sites. These inventories have resulted in over 250 rattlesnake locations. Of the many sites we located in inventories, we selected a subset and have launched a monitoring program that tracks breeding effort.

This year is our first year conducting monitoring at gestation sites, and of the 30 monitoring sites, we have only documented gravid females at three sites but most are being used as sites for snakes to shed their skin. At first this might sound alarming, but the number of Timber Rattlesnakes gravid in a given year follows a cyclic pattern based on prey availability in previous years. Also because of cycling of prey populations, the number of gravid females becomes somewhat synchronized. Thus, we would expect to see some years with high numbers of gravid females and some years with low. Our monitoring overtime will begin to document these cyclic pregnancy patterns and, combined with monitoring data on the forest and prey, will provide information critical for determining the stability of rattlesnakes in the region. Stay tuned, we are expecting much higher numbers of gestating Timber Rattlesnakes next year.

We are also beginning research to examine aspects of their ecology, such as their overwintering behavior and the effect of fire on foraging and basking habitats. Historically, many of the sites Timber Rattlesnakes would use for gestation would maintain open canopy characteristics through disturbance such as fire. But in many parts of the region, fire has been removed from the system. In addition, fire would affect the summer habitat of foraging snakes and their prey populations. Our research on fire and snake habitat will provide critical information to groups such as the U.S. Forest Service for management of our national forests.

Perhaps the greatest threat that Timber Rattlesnakes face in the southern Blue Ridge Mountains is direct persecution by humans. In an effort to lower persecution rates, we have launched a focused education-outreach effort. We give one to two-hour programs that focus on biology, ‘myth-busting’ and snake safety to communities throughout the region. These programs include a live animal demonstration, and we are currently developing a survey protocol that will allow us to determine if the programs are having short and long-term impacts on the ways people think about and interact with rattlesnakes. Our hope is that these programs will make people pause and think before they decide to kill a rattlesnake they see in the forest.

Back on the mountain… as I walk back to my truck from those high ridges, I am thinking about our programs to save the special connection these Timber Rattlesnakes have to these wild places. Timber Rattlesnakes are incredible icons for wild places in eastern North America, and many of these wild places help define our heritage and culture. In providing a place for the last great predator of the east, we are ensuring that wild places remain part of who we are.