Eastern Diamondbacks Fitted With GPS Units
Ever wonder how far these jokers will slither? A 10-year study on Jekyll Island reveals all kinds of snake trivia.
According to a Gallup poll, 51% of the population has a fear of snakes. In Georgia, one of the largest venomous snakes is the eastern diamondback rattlesnake. It is known by the scientific name Crotalus adamanteus. The eastern diamondback is found below the Fall Line in Georgia in the Coastal Plain. Their range extends out to the barrier islands of Georgia, many of which are protected and have limited development.
I, like the 51% in the Gallop poll, once had a great fear of snakes, but with each encounter I have had with them over the years, I now have a deep respect for snakes, including venomous snakes. I have learned they have a role to play in the ecosystem like other animals and have just as much desire to avoid us as we do to avoid them.
I recently had the privilege of meeting Jekyll Island Authority (JIA) Wildlife Biologist Joseph Colbert, who currently heads the JIA research team on Jekyll. I was able to go into the field with him and learn more about the eastern diamondback.
In 2011, researchers at the JIA began to study the population on the Georgia barrier island. Very little research had been done at that time focusing on the eastern diamondback, and with sightings dropping, researchers wondered if possible federal protection was needed in some areas. Information gathered by the research has shed new light on a snake that often goes unseen in the shadows. It has answered many questions and posed some new questions to be researched.
Another reason for the study is to understand the impact of development on the eastern diamondback. When areas have the underlying brush cleared, the rattlesnakes tend to move away from those areas. Being a top predator on the food chain, especially on an island, this could greatly impact the ecosystem, allowing some species to go unchecked with no, or limited, predators. The study wanted to see what kinds of development limited its impact on the eastern diamondbacks but also minimized human/diamondback interactions.
They currently are tracking 13 eastern diamondbacks on Jekyll Island. Since 2011, they have tracked approximately 47 diamondbacks on Jekyll. Many visitors to this barrier island and even residents have never seen a diamondback on the island. Prior to my day in the field with Joseph, I had never seen one on my numerous trips on the island. I have explored a lot of the trails on the island, but I have never ventured into the palmetto thickets or the protected dunes.
One thing that I found to be very interesting is the frequency in which the diamondbacks on the island typically feed, and what their food of choice typically is. Mature diamondbacks on Jekyll tend to feed almost strictly on marsh rabbits. If you have driven around Jekyll at sunrise or sunset, you know the abundance of marsh rabbits on the island. On average, diamondbacks on the island eat 0.94 marsh rabbits a year in the maritime forest and 1.6 in the dunes. Some rattlers have been known to eat as many as five marsh rabbits in a year.
Younger diamondbacks tend to eat mice, rats and the occasional smaller marsh rabbit. However, once they reach 3 feet in length, their diet is mainly marsh rabbits, which who can blame them. I like fried or stewed rabbit myself.
When I asked Joseph how they know when a diamondback has fed, he told me that since they are cold blooded, diamondbacks will find a location to remain hidden to allow their food to digest, only moving occasionally. Also, the visual food bulge is present for up to a month in cold weather. The time it takes a diamondback on the island to digest its food depends on the temperature. The warmer it is, the faster they can digest their meal and the sooner they will need to feed again.
On Jekyll, with its milder winters, diamondbacks tend to go into a state of hibernation around the end of October. The locations they prefer to hibernate are root masses from trees blown down from hurricanes and other storms and other piles of materials that offer thermal shelter. They will occasionally venture out when the temperature warms for several days in a row. Hibernation tends to end in late February or March most years, with diamondbacks becoming more mobile as the temperatures increase.
The home range for the diamondbacks that have been tracked can vary from as little as 5 acres to as many as 50 acres, depending on the amount of food available in the habitat they spend their time in, much like the range of any animal. Eastern diamondbacks in the dunes and marshes tend to travel less due to the abundance of marsh rabbits, squirrels, rats, mice and other prey, but in the forested areas of the island, they travel more since marsh rabbits are found in less abundance in these areas.
The diamondbacks also have learned to avoid interactions with humans. Diamondbacks on Jekyll Island tend to avoid crossing roads, which has almost created snakes with certain characteristics in different areas of the island. It has also created a limited gene pool for the diamondbacks. They also tend to avoid open areas such as yards.
Eastern diamondbacks have also learned to use the protected dunes as travel corridors since human travel in these areas are prohibited by law to protect the dunes.
The study is also showing that the diamondbacks are utilizing the corridors that are being left for other wildlife within some of the newer developments. This knowledge can now be applied, not only for eastern diamondbacks, but also for other species in developments across the United States.
I was shocked to learn how little diamondbacks reproduce. Most females will only reproduce once in their lifetime. Five to eight years is the time range it takes a diamondback to reproduce. With most diamondbacks in the wild living 15 years or less, you can understand why a good number of females only have one opportunity to help continue the species. If a female diamondback is killed accidentally or on purpose, it can have a significant impact on the local population, certainly much greater than the harvest of a whitetail doe on a local deer population.
A lot of you might be saying at this point that all of this is interesting information, but you still hate snakes, especially venomous ones. I can completely understand. I once felt the only good snake was a dead snake. Over time, and with repeated interactions with venomous and nonvenomous snakes, I began to respect them and had a desire to learn more about them, which is part of what caused me to reach out to Joseph.
If your main goal is simply to avoid snakes, then avoid the edges of habitat. Like deer, eastern diamondbacks tend to hunt in the shadows created along the edges of habitat. Also avoid walking in areas where you cannot see the ground. The pattern that gives the diamondback its name is not by chance. It is selective adaptation to help them remain hidden in the shadows to avoid being detected by their prey and remaining hidden from those that prey on them, including humans. I have said that if you want a good camo pattern, copy nature, especially a top predator like a diamondback. If you have to enter the shadows, buy a good pair of snake boots. Fortunately, I have never had to see if mine work or not, but the fact that I have them makes me feel safer.
In more than 7,000 encounters to date, Joseph said that a diamondback has never struck him or a member of his staff. In fact, he listed the following as the top-three circumstances when people are bitten: 1. When men aged 18 to 35 have a blood-alcohol content greater than .08 and intentionally handle a snake; 2. Amateur herpetologists handle a snake; 3. People attempt to kill a snake.
The researchers involved in the Jekyll Island study know the location of the tagged diamondbacks. They have multiple encounters each year with these snakes. Most of the time when these scientists approach the location of a diamondback, the snake will remain still as it relies on its camo to work.
The day when I tagged along, we all walked right past one of the largest snakes in their study, a 5-foot, 9-inch diamondback male. None of us saw him. It wasn’t until the pings on the antennae showed that the transmitter was behind us did we know. When we backtracked our steps, he was a few feet off the trail that we walked in on. At that point he was slithering deeper into the shadows created by the thick brush of the dunes. It has been discovered that they will slip away, hopefully undetected. It is usually not until they have no other choice will they enter a defensive posture through coiling and/or rattling. It’s at that point when they have exposed themselves to the threat.
Hiding himself was not an option on this particular day. As we got close to crossing the imaginary line or retreat or defend, he let us know when we were close enough. He simply stopped moving and raised his head maybe a half inch. That was his way of telling us we were close enough. When we stopped moving, he continued deeper into the shadows, moving slow and stealthy until he was no longer visible.
The snake I got the privilege of seeing was waiting along what appeared to be a rabbit trail. While I have been deer hunting, I have seen a timber rattlesnake move behind a limb of a blown-down white oak. It slowly contracted and relaxed its body until it was completely covered by leaves. If you did not know it was there, you would have never seen it while walking by. Why was it there you ask? All day long, what had been using that limb as a highway? A squirrel and several chipmunks.
There are several reasons I feel we should do our best to allow these diamondbacks to live when we come into contact with them out in the wild. They help keep the ecosystem in balance. They also help to keep an area from becoming overrun by rodents. Rattlesnake venom is also currently being used in the treatment of some diseases, such as breast cancer. Eastern diamondback venom on Jekyll Island was studied recently and found to be different than the venom collected in any other location. Joseph told me that the researcher studying their venom found that snakes in western Florida, Alabama and Mississippi had unique venom. Diamondbacks in the rest of Florida and up the Atlantic Coast were unique, and for some genetic reason the eastern diamondbacks on Jekyll Island were different than all of them. Who knows what diseases medical researchers might find cures for with each of the different venoms, possibly saving your life or that of someone close to you.
I hope this article has helped to shed some light on one of the creatures of the shadows that little is known about. If this article does nothing more than to help you learn more about the eastern diamondback and maybe start you to thinking more about their role in the ecosystem, then it has served its purpose.
Enjoy your time in the great outdoors! Stay safe, and when you get a chance, take a kid or someone new hunting or fishing.
Other Articles You Might Enjoy