Natural History: Carolina Pigmy Rattlesnake

I had an amazing opportunity to partake in a herpetology survey in a local national forest, where a portion had undergone prescribed burning in the previous week. The ground was black from the ash of the burnt vegetation and although it was cloudy that day, you could still feel some heat radiating from it as it made the surface of the ground warmer than the surrounding air. Our goal was to find rare species of that area for documentation and further research, with one of the animals being the well-known Eastern Diamondback Rattlesnake (Crotalus adamanteus), a personal favorite of mine. While walking through the sparse woods, the vegetation crunching under my hiking boots, it almost seemed hopeless to see any kind of snake due to the lack of sun, though. It was relatively chilly out as well, so I almost lost hope to see many snakes until my group and I stopped briefly along a trail. While investigating near a hollowed log, I caught a bright coloration out of the corner of my eye and saw the first snake of the day, a Carolina pigmy rattlesnake (Sistrurus miliarus). While not the one we sought, it was an exciting sign since it meant that the snakes were indeed coming out to take advantage of any warmth from the ground.

I estimate that this little rattlesnake was only between 5 to 6 inches long, being a baby while the adult form typically grows to be between 15 and 21 inches long. Unfortunately, no sex could be determined with confidence due to how small it was and the fact that it was curled with its tail hidden, which is typically looked at for sex determination. Also, we could not clearly see the rattle and had to look at other distinguishing features to make a positive identification at first. Once some high definition pictures focusing on its head were taken, it can be seen that it has a facial pit, which automatically told us that it was of the family Crotalidae. Its head was also wider than its neck, giving a classic V-shaped head rather than a rounded one. Next was the brilliant pattern it was presenting to us! I was amazed to see how colorful it was, but it allowed a clear look at the pattern of the dark lateral spots in a row on its sides and the middorsal “russet stripe,” or in other words alternating colored stripes of red and black or dark gray. The russet stripe is original to S. miliarus compared to the other rattlesnakes and venomous snakes of the area. Sistrurus also have a group of nine plates on the crown of the head that distinguishes them from the other rattlesnakes. Due to the tiny rattle and very slender tail of this species, even if it rattled (which an adult female did for us only a few minutes later after we continued our search), we would not be able to hear it. S. miliarus is considered to use more visual warning out of the rattlesnakes because of the small rattle that releases such a quiet sound, explaining why it has likely evolved brighter coloration than other rattlesnakes of the area. I was ecstatic when I came across this handsome rattlesnakes, partly because it meant more snakes would be out, but also because it was my first rattlesnake experience in the wild. The experience will never leave my mind and even as I write this, I cannot stop smiling because of how amazing that one moment was in my life.