Hello everyone, my name is Evan, and I’m a new Herpetology Keeper here at Zoo Atlanta. I recently moved to Atlanta from Kansas City, where I grew up. As a kid, I was always very fascinated by the different native snake species in Missouri, and particularly the timber rattlesnake. This large rattlesnake species has such an enormous range, all across the eastern United States, that fortunately I can still find them here in Georgia!
What I want to talk about today, and why this is one of my favorite species, is that because of this large range, timber rattlesnakes have a great amount of variation in ecology, size, and coloration. In terms of their ecology, their preferred habitat varies across different regions of the eastern United States. Here in Georgia and the Southeast, they can be found commonly in drier temperate forests where their favorite prey, rodents, live. However, in the Appalachian Mountains and the northeast, they are much rarer and are often only found where suitable denning habitat is found. This is typically rocky outcrops where they can spend the colder winters brumating. The rocks provide a thermal conductor of heat in higher elevations where it doesn’t get as warm, and gives them suitable places to raise their young as well.
The difference in ecology has also led to different colorations and sizes between areas that are so distinct that they were once considered different subspecies. In the coastal plains and lower piedmont areas of the southeast, they are often called “canebrake” rattlesnakes due to often being found in canebrakes, which are areas of thick grasses (or cane) and shrubs. Similarly, the name timber rattlesnake comes from the snakes living in areas with large trees that were historically logged for timber in the Appalachian region. The patterns of “canebrakes” are a light brown or gray with purple hues while also having darker brown or black bands throughout the body. Often, they have a brown stripe that runs along the spine. Further northeast in the Appalachians, the populations are on average smaller, and the light brown base is much darker and can cause almost completely black individuals in some areas, although many populations also have bright yellow individuals. It is thought the darker colors may allow them to absorb more heat in these colder climates. Despite these differences in appearance and behavior, there is no evidence of significant genetic diversity to split up the timber rattlesnake into different species or even subspecies. Here at Zoo Atlanta at Scaly Slimy Spectacular, we have two very nice examples of “Canebrakes.” Our male is slightly yellow, while our female is almost purple in coloration, and you can really see that distinct brown stripe down their backs!
This beautiful species of snake has historically been completely misunderstood as a danger and a pest animal to the point that rattlesnake roundups have occurred all throughout the eastern United States. In some states, people were paid bounties by local governments per foot of rattlesnake that they were able to kill in order to “control” their populations. These roundups and bounty systems have caused their numbers to decline drastically to the point where they are now threatened in the northeast. Unfortunately, rattlesnake roundups still occur in some southern states and are causing timber rattlesnakes to become more and more threatened. Despite the bad press, rattlesnakes are very beneficial to our environment and for humans as they control our rodent populations. They have even been correlated with lowered Lyme’s disease levels as they eat rodents that carry infected ticks. Despite their toxic venom, they are usually very reclusive and seldom bite, with fatalities only occurring rarely due to advances in snakebite treatment. Usually, most snakebites occur when humans are attempting to handle or kill a rattlesnake. These snakes would just prefer to be left alone and will often warn you with their rattle if you get too close. In order to best ensure that these important snakes have the best chance at surviving, we can give them the respect that they deserve and leave them be as well as educate others to do the same!
Keeper I, Herpetology
(photo: Robert H.)