Story and photos by Kenton Lohraff
Snake season means it is time for increased snake activity and a higher likelihood people may encounter potentially dangerous species.
Reptiles are ectothermic, and they must absorb heat energy directly from the sun or from their environment to maintain optimum body temperatures.
Many species will bask in the sun or absorb latent heat through elements in their environment that hold heat such as rocks and other hard surfaces. That is why aquatic turtles lay on logs and why snakes sometimes come out on sidewalks and trails in the evenings – especially this time of year as nights begin to get cooler and snakes are still active but must work to regulate their body temperatures.
Snakes in temperate regions like Missouri become inactive during the winter and tend to be most active in early summer and again this time of year, in early autumn, especially after rains, so be mindful of snakes that can be just about anywhere on the installation, even in cantonment areas.
Fort Leonard Wood is home to many unique species of wildlife, including some species that can be dangerous such as venomous snakes. Of the 10,000 species of reptiles in the world about 3,000 are snakes. The other reptile groups include turtles, lizards, tuataras (lizard-like unique reptiles) and crocodilians.
A total of about 72 different species of reptiles including turtles, snakes, and lizards, reside in Missouri. The Directorate of Public Works Environmental Division, Natural Resources Branch, manages and maintains records of all wildlife species on Fort Leonard Wood and maintains records of 42 species of reptiles, including six lizards, 11 turtles, and 25 species of snakes, three of which are venomous and could potentially be a hazard to people.
Missouri has five species of venomous snakes, all in the viper family: Osage copperhead, western cottonmouth (also known as water moccasin), timber rattlesnake, eastern massasauga rattlesnake, and western pygmy rattlesnake. These vipers have pits on the sides of their heads that can detect heat from mammalian prey, such as mice, and of course the notorious fangs which are hollow delivery devices which can channel and inject venom. The venom assists these species in immobilizing their prey but also acts as a potent, and sometimes deadly, defensive mechanism when they bite.
Three of those venomous species are recorded on Fort Leonard Wood: the Osage copperhead, western cottonmouth, or water moccasin, and the timber rattlesnake. Copperheads are very common throughout the installation and cottonmouths are also abundant along our streams like the Big Piney River and Roubidoux Creek.
The timber rattlesnake, the most widespread of all the rattlesnakes in the eastern United States, can be abundant regionally but is uncommon. Massasauga rattlesnakes prefer the specific habitats of large moist prairie and wetland areas in northern Missouri, the western pygmy rattlesnake occurs just to the south of the Fort Leonard Wood area.
Venomous means a particular animal has a toxin, such as venom, and the capability of injecting that venom into other organisms with their hollow fangs present in Missouri’s cottonmouths, rattlesnakes, and copperheads. They do this as a means of immobilizing prey but a venomous bite can also be administered as a defensive mechanism to potential threatening organisms, including humans.
The word “poisonous” generally means an organism has a toxin that can negatively affect other species but it has to be ingested or touched, so a poisonous species is not capable of injecting the toxin into other organisms.
Sometimes snake species are misidentified. There are quite a variety of colors and patterns of snakes on Fort Leonard Wood and some change looks as they change from juveniles to adults. Copperheads have a distinctive hourglass brown-tan-white pattern and cottonmouths vary from brightly bronze, or coppery, to nearly black. Both of these species tend to be primarily nocturnal but as temperatures cool, can be observed basking more often during daylight hours.
Other species that sometimes are misidentified as venomous include water snakes, ratsnakes, hognose snakes, racers, coachwhips, and kingsnakes. Both prairie and speckled kingsnakes are immune to the venom from copperheads and cottonmouths and, being fast-acting powerful constrictors, can actually prey on these venomous snakes. All species of snakes are protected in Missouri.
Only rattlesnakes have the distinctive rattles at the tips of their tails and new segments are added as each snake grows and sheds its skin. Many snakes “rattle” their tail when disturbed or agitated and if they happen to be next to dry leaves a rattle noise may be audible. With rattlesnakes and other snakes that exhibit this behavior it is a general warning. From snake language, a general interpretation of the behavior means “You are too close to me now. Back off.”
Both the cottonmouth and the copperhead are closely related and have broad, triangular heads with venom sacs behind the pits and also have distinctive vertical pupils. If you are close enough to see that then you are likely too close for comfort.
Cottonmouths also have the notorious habit of flashing open their white mouths, hence the name “cottonmouth”, at close encounters – if you see that, back away, slowly, if possible, and leave the area. The snake is demanding respect and more personal space and at that point, they deserve it.
Most snakes are shy and will avoid people if given a reasonable chance. Even copperheads and cottonmouths oftentimes try to escape first at a close encounter with a human and will only bite as a last resort. Even though these snakes have the potential to harm humans, they are native wildlife species that perform unique functions in our environment.
While most reptiles lay eggs, both of these species are viviparous so they have live birth. Another unique feature of juvenile copperheads is a distinctive greenish-yellow tail that they can wiggle as a lure to attract potential prey.
The first thing to do when encountering any snake is to back off, give it space, and leave it alone if possible. Many unfortunate venomous snake encounters with humans occur when people are attempting to catch or move the snake. It is best not to disturb it if possible.
Sometimes people accidentally step on them, especially in low-light conditions, and that obviously can lead to undesirable consequences. What you think may be a stick may actually be an Osage copperhead that has come out to absorb some heat from the ground, trail, or sidewalk.
Cottonmouths are usually found along streams — especially along the Big Piney River and Roubidoux Creek on Fort Leonard Wood. They are usually very reclusive but can be inquisitive and can get close to people accidentally or if they smell fish nearby. While along the waterways, be particularly aware at rocky and dense brushy areas. The common northern watersnake is not venomous but can also bite if handled or foolishly treated.
Some tips to avoid a negative encounter with a venomous snake include, first, to simply be aware that they are out there on FLW so if you do encounter one, try and remain calm and keep a respectable distance from the snake. Both venomous species are native, and quite common here, and play a roles in healthy functioning ecosystems. Learn to identify the copperhead and cottonmouth, and if you do encounter one leave it alone if possible. Many snakebites occur when people attempt handling or removal of the snake.
Watch where you step if walking in wooded or rocky areas. Don’t walk at night without a light – copperheads tend to come out on trails and even sidewalks especially in the evenings or after dark. Take special care with children and pets to make sure they don’t accidentally step on, or too close to, a venomous snake.
General Leonard Wood Army Community Hospital’s Environmental Health provides numerous public outreach educational booths and public safety demonstrations at community events on FLW throughout the year about potentially dangerous critters including venomous snakes. In the unfortunate circumstance of a snakebite, if you cannot positively identify the offending species as non-venomous, the GLWACH Emergency Department advises to call 911. When taken care of quickly at the hospital most snakebite victims have an excellent likelihood of recovery.
For more information about the venomous snakes of Fort Leonard Wood contact GLWACH Environmental Health at 573.596.4913, or DPW Natural Resources at 573.596.2814.
(Editor’s note: Lohraff is Natural Resources Branch Chief at Fort Leonard Wood, Directorate of Public Works Environmental Division.)