Misplaced Fears: Rattlesnakes Are Not as Dangerous as Ladders, Trees, Dogs, or Large TVs

May 10, 2016

In Southern California, rattlesnakes can be seen year round, but spring and summer have the most rattlesnake activity. This also means that these months generate the most concerns about rattlesnake bites. The good news, however, is that here in the United States, the fear of venomous snakebite seems to far outweigh the actual chance of being bitten. Let’s take a closer look at the statistics behind venomous snakebites. 

A typical Southern California rattlesnake encounter. Here, a large Southern Pacific Rattlesnake crosses a dirt road in the Santa Monica Mountains.  In the U.S., the snakes typically involved in human fatalities include native species like rattlesnakes, copperheads, and cottonmouths as well as a number of nonnative species that are sometimes kept as pets, both legally and illegally, and zoo animals. There are also three species of coral snakes in the U.S., but with their small mouths and fangs, bites to people are rare and usually involve a person handling the snake. To avoid being bitten by a coral snake, follow this simple rule: don’t pick it up. Here in Southern California, there are seven species of rattlesnakes (making this herpetologist quite happy to live here). Most are found in the deserts, but the Southern Pacific Rattlesnake is common in the foothills and mountains surrounding the larger coastal cities.  Each year, around 7,000–8,000 people are bitten by venomous snakes in the U.S. This may sound like a large number, but given that the U.S. population is quickly approaching 324 million people, this represents a tiny proportion of the population (less than 0.0025%). Of these 8,000 or so bites, on average, 5–6 result in fatalities (Table 1). This means, you are 6 times more likely to die from a lightning strike or a dog attack, 8 times more likely to die from a TV set or other large furniture falling on you, 14 times more likely to die falling out of a tree, and 95 times more likely to die falling off a ladder. Of course all of these numbers pale in comparison to risks posed by car accidents (over 30,000 fatalities per year) or of dying of heart disease or cancer, which are the two leading causes of mortality in the U.S. (Table 1). Despite the reality of the low risks from animal attacks in the U.S., snakebites and also shark bites (less than one fatality per year in the U.S.) get a huge amount of attention in the popular press. 

Data from the Centers for Disease Control and Prevention (CDC) Wonder database for the most recent year available (2014) except as noted by the asterisk, for which information is from the U.S. Consumer Products Safety Commission for 2011. How do venomous snakebites happen? The sad reality is that many (very likely most) bites result from poor decisions by people. Bites are divided into two categories, legitimate and illegitimate. If the person never recognized the snake or was in the process of moving away from it when he/she was bit, it is considered legitimate. But if the person recognized the snake but did nothing to move away, it is termed illegitimate. Many of these illegitimate bites involve people handling or harassing the snake. Studies that reviewed U.S. hospital records have found that over 50% of venomous snakebites are illegitimate (up to 67% in one study), meaning the person put her or himself (usually him—see below) in harm’s way. In other words, the snakes are getting blamed for people making bad choices. These illegitimate bites include people keeping venomous pet snakes, religious snake handlers, professional snake handlers, and people who aggravated a snake in the wild such as by trying to catch or kill it.  Not surprisingly, most of these illegitimate bites occur to the hands, and the victim is usually a male. In one review of 86 rattlesnake bite victims in Arizona, males accounted for 87% of bite victims. Many of the people who get bitten while intentionally interacting with a venomous snake were also intoxicated at the time (up to 57% of illegitimate bites in one study).  For legitimate bites, most occur to the lower extremities because the victim did not see the snake and walked up to it or accidentally stepped on it. The intoxication rate is also much lower for legitimate bites. So what are the take-home messages from these numbers? GET OUTSIDE! Go for a hike, a bike ride, or a jog. Regular exercise helps to prevent heart disease, the number one cause of death in the U.S., and also reduces the risk of diabetes. But on your way to and from the trailhead, drive carefully! Sure there are some critters out there that can inflict pain and possibly even cause death, but if you stay observant, watch your step, and treat wildlife with appropriate respect, you can avoid most of these uncommon threats. And if you do come across a venomous snake, let it be. This seems so obvious, yet it is likely that more than half of the venomous snakebites in the U.S. happen because people didn’t follow this commonsense practice. Take a few steps back and then take some photos. Enjoy the opportunity to see such a beautiful animal. And, of course, if you are in Southern California, please submit that photo to our Reptiles and Amphibians of Southern California citizen science project. For more info: An excellent blog that examines both U.S. and global concerns about venomous snakebite: Selected references: Curry, S. C., D. Horning, P. Brady, R. Requa, D. B. Kunkel, and M. V. Vance. 1989. The legitimacy of rattlesnake bites in central Arizona. Annals of Emergency Medicine 18:658–663. Morandi, N., and J. Williams. 1997. Snakebite injuries: Contributing factors and intentionality of exposure. Wilderness and Environmental Medicine 8: 152–155. Spano, S., F. Macias, B. Snowden, and R. Vohra. 2013. Snakebite Survivors Club: Retrospective review of rattlesnake bites in Central California. Toxicon 69:38–41.

 

(Posted by: Greg Pauly)

16 Comments

What about baby or immature rattlers. Do they rattle and are they dangerous?

Baby, or juvenile and sub adult snakes are way more venomous as they can't control venom output. The venom is still the same potency and the yield is smaller in volume, but just as deadly. Picture turning a focet on full blast and trying to fill a balloon before attaching it to the focet. That's how all young and venomous creatures are.

Baby, or juvenile and sub adult snakes are way more venomous as they can't control venom output. The venom is still the same potency and the yield is smaller in volume, but just as deadly. Picture turning a focet on full blast and trying to fill a balloon before attaching it to the focet. That's how all young and venomous creatures are. And depending upon age, they may or may not have a rattle.

Vt, it is a common belief that baby venomous snakes are more dangerous because they can't control venom output, but there is actually no solid data to support this argument. Moreover, there is evidence indicating venom metering in juvenile rattlesnakes. A similar argument suggests that dry bites (bites from venomous snakes in which no venom is injected) are more common in adult snakes because the young ones can't control venom output, but again there is no conclusive evidence of this. As above, there is also evidence of venom metering in young snakes, though more work needs to be done to understand variation in dry bite frequency across species and different age classes within species. What we do know is that the venom glad of adult snakes has a much greater volume, and therefore the adults are capable of delivering far more venom. Don't believe the common myth. The reality is that larger snakes are capable of producing much more severe envenomations.

The oft repeated belief that a bite/envenomation from neonate, juvenile or subadult rattlesnakes poses a greater threat to humans than adult counterparts because "they can't control venom output" is a fallacy, and unsupported by peer-reviewed scientific literature. An old wives tale. For the sake of argument let's assume a young rattlesnake does indeed lack physiological mechanism to regulate venom delivery... so what? The volume of venom possessed by newborn rattlesnakes is minuscule when compared to its parents. The greater the volume of venom injected the greater the danger to human victims.

Great to be able to put this "hazard" in perspective. Thanks Dr. Pauly!

Great info, and it definitely puts things in perspective. As somebody who hikes and runs on trails a lot this is good info to have, but maybe should have included what to do if we do get bit? (Obviously I've googled it, but others may like to have that information included here)

If you are bitten, your best bet is to get to a hospital. Try to stay calm, reduce movement as much as possible. Splinting the limb to immobilize is helpful. Crofab now has a great mobile app called SnakeBite911 and it's available for free. Download to your phone and it will give you step by step instructions on what to do. There are three apps available...one for the general public, one for first responders and one for ER physicians. It's a good idea to mark the bite site and any swelling along with the time, take a photo of the bite area so doctor's can compare. Do not use tourniquets, cut the bite or attempt to suck the venom out. Almost all hospitals in the US carry Crofab in the ER if there are venomous snakes in the state. All North American pitvipers are treated with the same antivenom. Poison control also has information on what to do for bites and this resource is available for ER physicians as well.

Great blog! I wish more people would respect and enjoy snakes of all kinds. In answer to the question about baby rattlers. Yes, they rattle but you'll probably not hear it as babies have only a single button when they are born....immature/sub adults will have more rattles but depending upon how many and what species you may or may not hear it. Not all rattlesnakes will rattle either. I've rarely had them rattle at me. Are they dangerous. Yes! They are every bit as venomous as their adult counterparts and in young snakes, the venom is somewhat more potent. However, the volume is much smaller and contrary to popular belief, they regulate just as well as an adult. The other thing is that a young, smaller animal might be more defensive and therefore more apt to bite. Give a snake space, and they will usually attempt to escape. No one was ever bitten by a snake they left alone....even legitimite bites are getting in the snake's space knowingly or not.

Great article. I've been bit by a Pacific Western adult on the lower leg in Santa Monica Mountains. I almost died but a helicopter ride, a week in icu and 21 vials of anti-venin and I made it! Do not approach snakes. Teach your kids. Have your dogs trained to avoid rattlesnakes and let them hike ahead of you. Canines can smell the difference between pit vipers and non venomous snakes. My goldens signal to me and literally lay across the trail. Often they don't rattle, mine was in the grass and didn't though after strike it did. If bitten, try to remain calm do NOT suck out the venom it will be in your brain in a few seconds. Most bites are dry (hit bone or localized muscle) mine was 'wet' went right into my main artery. Had to hike out fully envenomated not fun. You bleed internally because the venom is an anti coagulant. It's also a neurotoxin so your ability to breathe and even think are severely impaired eventually leading to death if anti venin is not given. Get emergency care immediately you've got about 3 hours in either scenario. I landed at hospital right about then. If you are in the Mojave and get bit by a rattler, assume it is the deadly Mojave and race to the hospital you've got about a half hour after wet bite. I didn't see the snake even though I'm extremely careful and experienced hiker. But my experience in wilderness areas and emergency situations was extremely helpful and I was able to prevent myself from going into shock. Again do not suck venom, do not tie off the limb, get to hospital in a flash! Happy hiking!!

Thanks for calling my blog "excellent"! I really appreciate the shout-out, especially about this important topic.

Thank you for this information. I recently moved to a very rural location with my young boys. Last summer my two year old found a rattlesnake and wanted to approach it. Since then I frequently dream of them, not all bad dreams, but not great either. Fearing the natives has been my biggest obstacle to enjoying my new homestead. I've seen five now in two years. It's better to be informed and aware rather than simply afraid. But it's hard to instill those lessons in the wild minds of three and six year olds. I hope we can live respectfully and gratefully distant from eachother.

I'm responding to two questions from the comments. 1) What do you do if you get bit by a rattlesnake? The good news in Southern California is that in most places, you are still in relatively close proximity to a hospital. If you get bit, the two most important goals are A) to remain calm and B) get to professional medical care as quickly as possible. Remove any restrictive clothing, watchbands, or jewelry. Try to track the time and the response to the envenomation, including marking the extent of swelling. If you are far from the trailhead, work to get emergency responders to the victim, such as a park ranger, helicopter evacuation, etc. DO NOT cut the bite marks, try to suck out venom, or use a venom removal device. There is no evidence these work and there is good evidence they make the situation worse. Also, DO NOT use a tourniquet. Wrapping limbs is appropriate for bites from elapids (cobras, coral snakes, and their close relatives), but should not be used with rattlesnakes. 2) What about baby rattlesnakes. Do they rattle and are they dangerous? The most obvious thing about baby rattlesnakes is that they are...cuter. That probably wasn't the answer you were looking for (true though it is). When rattlesnakes are born (rattlesnakes have live birth), they don't have a rattle. Instead they have a tiny prebutton, which is a little scale cap made of keratin at the tip of the tail. Within a few days of birth, the babies shed and the prebutton is replaced by a button. Each time the snake sheds it will get a new rattle segment. Thus, when the snake only has a button it can't make a rattle sound because there is nothing for the button to rattle against. Even after its next shed, the small rattle, with only two segments doesn't produce much sound. It takes a couple of segments before the snake is capable of producing the louder rattle sound that we can hear when we get too close to a rattlesnake. Yes, the babies are dangerous. They are capable of injecting venom, though the amount they can inject is much less than that of an adult simply because their venom glands are much smaller. Nevertheless, an envenomation from a young rattlesnake is a medical emergency and the victim needs to get to a hospital as quickly as possible.

I wrote up a brief comment but I don't know if I posted it right so I'm writing it here as well. My daughter, 30 months old at the time and weighing about 30 lbs, was bitten 3 times by a prairie rattler in Nutrioso, Arizona at 7,200 ft elevation which is generally considered too cold for many snakes. The snake had no rattles and therefore no sound, only a mangled tail which is why I didn’t hear it. She received 20 vials of antivenom and was inpatient at the local hospital for 4 days. I have the newspaper article, photos of her leg and photos of the snake. She had two “wet” bites in her calf and a “dry” bite in her ankle. I didn’t address her bites at all, other than to have her prone in the back seat of the car instead of sitting up in her child seat and with a pack of frozen peas on her leg and her Fisher-Price music player going for her presence of mind. She never cried or got upset and I never let on anything was amiss. The hospital was 15 miles away and I wasn’t about to wait for help to arrive, just went straight to the ER. For identification purposes I did take in the head of the snake in my cookie tin. The snake was at least a yard long. Her medical chart said she had a grade 3 envenomation. She had no loss of tissue. Her pediatrician thought she wasn’t going to make it at first (ignorance is bliss, for he never told me that at the time) and it was about 8 hours before the swelling stopped increasing. Today, 30 years later the only evidence is two marble like lumps in her calf.

Your nationwide statistics are not very comforting for folks who live in high risk rattler territory. Most people live in cities and in other places not shared with deadly venomous rattlesnakes. Awesome creatures, but worth looking out for in their territory. Dusk is a bad time to be walking to the stock tank in West Texas.

I can put this stupid"baby rattlesnakes are way more deadly than adults" BS to rest right now.I have two western diamond backs.One is 5'1/2 ft long, as big around as your forearm,with a head almost as big as your fist and bulging venom glands and fangs almost an inch long.The other is a neonate--10" long,smaller than a pencil, the head the size of a sunflower seed and fangs 1/4 " at best.You get to choose which cage you must stick your hand into and get bitten.Defense rests it's case---

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