Rattlesnake Awareness

Be Rattlesnake Safe

Wildlife biologist and educator Mike Cardwell has spent years studying rattlesnakes along the American River Parkway and elsewhere. He answers questions about rattlesnakes in the following Q&A:

What is your background as it relates to rattlesnakes?

I’ve been lecturing, writing, consulting and doing field research with rattlesnakes for many years and am currently an adjunct researcher with San Diego State University. I have a graduate degree in biology, earned with a thesis on rattlesnake behavior during drought.

What are the most important things residents in our neighborhood adjacent to the American River Parkway should know about rattlesnakes?

Living along the Parkway means living with rattlesnakes. Our part of California is home to the Northern Pacific Rattlesnake (Crotalus oreganus oreganus). For detailed information about this snake, CLICK HERE

These rattlesnakes are shy, secretive and cryptic and my four-year radio telemetry study at Effie Yeaw Nature Center discovered that there are far more of them along the river than anyone previously suspected.

What are the most prevalent myths about rattlesnakes?

Rattlesnakes don’t attack or chase people. If they did, YouTube would be full of the videos. But that doesn’t mean that they won’t defend themselves vigorously, whether you’ve bothered them intentionally or by accident.

Bites by baby rattlesnakes are less dangerous than those of adults, not more dangerous as many people claim. There is lots of evidence that really bad bites are delivered by larger rattlesnakes. Even if the little guys inject all their venom, their venom glands are tiny compared to those of larger rattlesnakes. Venom yield is directly related to snake size.

Please describe the life cycle of rattlesnakes.

The rattlesnakes found around the American River mate in both spring and fall. Females give birth to live young, usually in late August or September. Average litter size is eight. If there is ample prey available – primarily voles, mice and ground squirrel pups – females may reproduce annually. But they often skip a year to replenish enough body fat to support another pregnancy. Baby rattlesnakes are about the size of pencils and spend the first ten days or so with their mother. They are venomous at birth and initially too small to eat most rodents, so they eat a lot of small lizards. Males reach sexual maturity at about 1½ years and females can be reproductive in about two years.

What should people do to be safe in rattlesnake areas?

This is summed up with two rules: (1) Don’t put your unprotected hands or feet where you can’t see or haven’t looked and (2) leave rattlesnakes alone when you find them. Stay at least twice the length of the snake away from rattlesnakes.

How can we keep rattlesnakes out of our yards?

A fence or wall that effectively excludes snakes is difficult and expensive to construct and is seldom 100% effective. Commercially available repellents have not been shown to work. The easiest and most effective thing to do is to eliminate places where snakes and mice can hide.

Rattlesnakes live on the ground and they rarely climb. So, you should do things like building a rack to keep firewood eight or so inches off the ground and trimming shrubs so you can see the bare ground under them. Don’t use bird feeders; they attract rodents and rodents attract rattlesnakes. Cover openings to drain pipes and crawlspaces under sheds, etc., with screen or hardware cloth.

The rule is that you find female rattlesnakes where there are resources like food and shelter and you find males where there are females. Female rattlesnakes don’t move around nearly as much as males and a clean, tidy yard with nothing to eat and no place to hide is not likely to attract a female. But we know that most encounters with people are with male rattlesnakes during spring and fall when they are wandering around looking for females. That’s when they often turn up in yards, on paths and all sorts of other places. It comes back to the two rules: watch where you put your hands and feet when you are in areas where rattlesnakes are likely to appear and leave them alone when you find them.

What should a person do if he or she is bitten?

Your best snakebite kit is your cell phone or car keys. I was a coauthor on the Wilderness Medical Society’s current treatment guidelines and it’s now well established that the only thing that can improve the outcome of a serious rattlesnake bite is antivenom, which is only available in hospitals.

None of the old first aid practices have been shown to be effective, some actually do damage, and all waste time. So, no cutting, suction, ice or ice water, compression bandages, or electricity. Serious rattlesnake bites destroy tissue and doctors who treat a lot of bites are fond of saying that “time is tissue.” In other words, antivenom cannot repair damage, it can only neutralize venom that has not yet caused damage. So, head for the nearest emergency room right away.

It’s impossible to know how much venom has been injected in the minutes following a bite and waiting to see if serious symptoms set in is a very bad idea. Paramedics will quickly and safely get a bitten person to hospital where antivenom is available if needed. If you’re out in the boondocks, drive safely but without delay to a hospital or where you can contact paramedics. A recent study that looked at almost 6,000 cases found three factors that significantly correlate with bad outcomes: delayed medical treatment, small patient size (i.e., young child) and a big snake.

It is comforting to know that fewer than one in a thousand snakebite victims die in the United States. More than 99.9% survive! Fatalities are rare.

How can we protect our pets – in particular dogs – against being bitten?

Do what you can to make your yard inhospitable to rattlesnakes. Keep dogs on a leash when you are walking where rattlesnake encounters are likely. Professional rattlesnake avoidance training is available – which usually involves a shock collar.

A rattlesnake vaccine is available from veterinarians. Most vets tell me that they’re not sure how much good it does, but it’s not expensive and their clients want it, so they provide it.

What should a pet owner do if a dog is bitten?

The best thing for the dog is take it to a veterinarian immediately. Like bitten people, early treatment is likely to produce better results. In general, dogs seem to do better than bitten people of similar body weight but a rattlesnake bite can certainly be fatal.

What final thoughts can you share about living near rattlesnakes?

I did a four-year radio telemetry study at Effie Yeaw Nature Center. I discovered that the rattlesnakes there are difficult to catch because, as soon as they are discovered, they disappear into thick vegetation or down a ground squirrel hole. They only coil and rattle if there is no place nearby to hide. They also often pass through yards without the homeowners knowing it.

Just because you don’t see many rattlesnakes doesn’t mean they are not around if you live within a few blocks of the parkway. More than once, we photographed these ambush predators at Effie Yeaw, coiled motionless in the weeds with their backs to a trail a few feet away while a constant stream of visitors walked back and forth on the trail. That does not include the many rattlesnakes we were not tracking. I only had radios implanted in about a dozen rattlesnakes at a time. We eventually captured and marked about 50 rattlesnakes and estimated that there were about that many that we never captured. Before the study, nobody thought there were a hundred adult rattlesnakes in EYNC’s 100-acre preserve.

That said, don’t be fearful of them. They are fascinating animals that want nothing to do with creatures as large as us.

My wife Denise and I now live on a rocky hillside in southern Arizona and we have three species of rattlesnakes on and around our property. Because of that, we make a habit of turning on lights and/or using a flashlight when we go outside at night. We always look before stepping out. Before grabbing a hose coiled on the ground, we glance around to be sure there is no coiled snake there. These are simple habits that become second nature.

Rattlesnakes deserve respect and caution, but not fear. You don’t have to be a rattlesnake researcher to enjoy and appreciate ALL the native wildlife around your house – including rattlesnakes.