Friday, July 3, 2015

The Serpent in the Garden

It's snake season in the Santa Monica Mountains and hikers, dog owners, gardeners and anyone who lives in the urban-wildland interface needs to be aware that we share our community with a wide range of reptiles, including this Southern Pacific rattlesnake. Photo @ 2015 S. Guldimann

We are blessed with an abundance of snakes in Malibu, the National Park Service lists a total of 14 species in the area, but the ones most often encountered are the shy ring-necked snake that feasts on slugs;  the beautiful and aptly named king snake; the gopher snake, which lives up to its name and preys on the bane of local gardeners; and the only venomous snake in the area, the Southern Pacific rattlesnake.

The biggest snake in Malibu is unquestionably Legacy Park's giant California mountain king snake. This mosaic sculpture is the only king snake likely to be encountered in much of coastal Malibu. When I was a child, the live version of this spectacular snake was a common Point Dume garden resident, along with its close relative, the black-and-yellow-striped California king snake, but development and habitat loss has pushed the range of both species back into the Santa Monica Mountains. This is unfortunate, since one of the king snake's favorite menu items is the rattlesnake. Photo: S. Guldimann

No one ever mistakes a king snake or a ringneck for a rattlesnake, but gopher snakes are another matter. This species mimics the rattler's markings and even its behavior, which may help protect it from predators, but does little to reassure humans.

The ringneck snake, Diadophis punctatus, is probably one of the most common garden snakes in Malibu, but its rarely seen, despite its dramatic coloring. The ringneck hunts for worms and slugs. It's harmless, beneficial, quite pretty, and not remotely frightening. It rarely grows to be more than a foot and a half long, and is an expert at not being seen. Photo: NPS
Spotting a snake in an unexpected place can be a shock, but it is the snake one doesn't see that usually causes problems. The vast majority of rattlesnake bites occur when the human victim of the bite accidentally comes into contact with an unseen snake. 

I was reminded of this the other day when the Loyal Dog and I were pottering in the garden. I bent to pick up a dead branch and found that the stick had been magically transformed into a snake. Fortunately, it was a gopher snake, not a rattlesnake, but the experience was a shock and reminder to me to pay attention.

We like to think of ourselves as experienced naturalists here at the Malibu Post, ready to encounter new creatures with aplomb and panache and things like that. I'm afraid this discovery elicited a shriek of horror. If you are going to mistake a snake for a stick, it's much better to make the mistake with a harmless gopher snake than a venomous rattlesnake, but it was still unnerving. Photo: S. Guldimann

With humans, bites to the ankle are estimated to be the most common, followed by bites to the hand and lower arm. With dogs and horses, noses are are often the bite location, as the curious mammal attempts to take a closer look at the snake.

A gopher snake really will mimic the rattlesnake, curling up and waving the end of its tail in a fairly convincing imitation of its venomous cousin. The California Herps website has an amazing video documenting this phenomenon. The quick movement masks the fact that the gopher snake has a slender tail and no rattles. Gopher snakes have small, narrow heads and their eyes have round pupils, although a dark mark under each eye can create the illusion of a vertical pupil. 

Here's a close-up of the gopher snake's eye. The pupil is round, but the dark mark makes it look—at first glance—like the vertical pupil of the rattlesnake. Photo: S. Guldimann

This is the Mexican ridge-nosed rattlesnake. It's not a local species, but it was the best example I could find of that verticle pupil that is a characteristic of all rattlesnakes. 
The coral snake is the only dangerously venomous North American snake that doesn't have the diamond-shaped head, and we do not have coral snakes in California. The Southern Pacific rattlesnake is Malibu's only venomous snake. There are several other rattlesnake species in Southern California, including the highly venomous Mojave green, but it is limited to inland areas. Photo: Robert S. Simmons, USFWS, via Wikipedia Commons

Rattlesnakes store their venom in their heads, giving them the distinctive diamond-shaped skull. Their eyes have a vertical pupil and they tend to be thicker and more robust than gopher snakes. If in doubt, it’s better not to take a closer look, especially since young rattlesnakes may lack the characteristic rattle, but can still deliver a dangerous bite.

This young Southern Pacific rattlesnake was snoozing under a piece of bark just feet from dozens of walkers at Paramount Ranch in Agoura Hills. You can see the distinctive diamond-shaped head that is characteristic of rattlesnakes, and the pattern, which can be bright and distinct as it is here, or so dark the snake appears almost solid black. Photo: S. Guldimann

In the first seconds of surprise at seeing a snake it can be hard to tell the species apart. According to a news report, an Idyllwild man was just bitten by a rattlesnake he mistook for a gopher snake

“I was just trying to shoo the snake out of the wood pile,” the 55-year-old Idyllwild resident told the Press Enterprise. “I thought it was a gopher snake, but it was a rattlesnake.”

The gopher snake has the same general color scheme as the Southern Pacific rattlesnake, but it's skinnier and tapers to a narrow, somewhat pointy head. If in doubt, just keep away. It's not worth making a mistake.

Staying on trails and away from deep brush, grass or rocks is the best way to avoid encounters with rattlesnakes. Never placing a hand or foot in an area where you can't visually scan for snakes is also key. 

I was once told by longtime snake wrangler Bruce Freeman that the other kind of rattlesnake bite risk starts with the words "hold my beer and watch this." His advice for dealing with snakes is to "always bring your brain."

According to snake wrangler Bruce Freeman, wearing hightop hiking shoes, thick socks and denim or twill pants really can protect hikers from snakebite. They may be comfortable, but minimalist trail running shoes are not advisable, especially when runners are out in the evening, when snakes are more likely to be in the open, using the warmth of the exposed trail to help thermoregulate.

He also recommends wearing high-top hiking and running shoes, and twill or denim pants for extra protection. Trail runners are at greater risk from snakebite than hikers, since they move faster and don't have time to look where they are putting their feet. 

Snakes can show up where they are least expected. Rattlesnakes often venture into Malibu gardens, and have been known to make their way into houses through open doors or even pet flaps. 

More than one Malibu family has heard a rattlesnake, displeased with finding itself in the laundry room or bathroom, making use of its rattle—which creates more of a hiss or a buzz than a rattling sound. It's a testament to the generally peace-loving nature of the snake that bites are not more common.

Here's a selection of audio samples of the rattling sound.

The number of "buttons" in the snake's rattle is not an indicator of age. This snake has four rattles, but that Lego-like knub at the end of the rattle indicates where additional buttons have broken off. A new button grows every time the snake sheds its skin. Young snakes shed more often than older snakes and all snakes may shed multiple times during the year depending on conditions. Photo: S. Guldimann

While snake fencing—fencing material that is buried several inches underground, can help reduce encounters with snakes it can’t eliminate them entirely, since rattlesnakes can travel under the fencing via gopher holes. A snake pole—a shepherd’s crook designed to safely move snakes, can be a helpful tool.  Making sure doors stay closed, and that screens don't have holes in them is important, too. 

There are  a number of local snake wranglers who will remove rattlers and safely relocate them away from human habitation for a fee. Calling an expert is by far the best option when a rattlesnake shows up in a house or garden. 

California Poison Control receives nearly 300 calls a year about rattlesnake bites. Children and small animals are at the greatest risk for serious complications or death. Some bites are "dry," a warning from the snake, who doesn't want to waste venom on something it knows it isn't going to eat, but all rattlesnake bites require immediate medical attention. The venom contains a powerful hemotoxin that attacks tissue and can damage the heart and cause organ failure and necrosis in severe cases. 

There is no way of knowing if the victim has received venom or a dry bite when the incident occurs and antivenin is essential for the patient's survival. Just because people rarely die from rattlesnake bites doesn't mean a bite can't be fatal—an estimated four or five bite victims die annually. The venom can also cause the loss of a limb. A rattlesnake bite is always a serious medical emergency.

One would think this means the rattlesnake would be safe from predators, but that's not the case. Rattlesnakes are venomous, not poisonous, and many species—including some humans, eat them (supposedly they taste like, you guessed it, chicken). Rattlers are preyed on not only by king snakes, which are immune to their venom, but by hawks, owls, weasels and road runners—species that use speed and evasion to avoid getting bitten.

Rattlesnakes, like gopher snakes, primarily dine on rodents, including gophers and ground squirels. They're an important part of the local ecosystem, just not a welcome backyard wildlife species.

According to the National Park Service, common Malibu-area snakes include the gopher snake (Pituophis catenifer), California kingsnake (Lampropeltus getulus), mountain kingsnake (Lampropeltus zonata), California striped racer (Masticophis lateralis), red coachwhip (Masticophis flagellum), two-striped garter snake (Thamnophis hammondii), blackhead snake (Tantilla planiceps), ringneck snake (Diadophis punctatus), and the yellowbelly racer(Coluber constrictor). Other less common species include the blind snake (Leptotyphlops humilis), coast patch-nosed snake (Salvadora hexalepis), night snake (Hypsiglena torquata), and the lyre snake (Trimorphodon biscutatus). Most of us will never encounter even half this list, but it's good to know who our reptilian neighbors are.

The Mountains Restoration Trust offers rattlesnake avoidance training for canines. It's not a pleasant experience for dogs or their owners but it can be a lifesaver for those who live in rattlesnake habitat or who frequently walk with their dogs in the mountains. 

I was covering a workshop on the master plan for Malibu Bluffs Park recently for the Malibu Surfside News. A young father with two boys said he never takes them to Malibu's Legacy Park because there are signs warning of the presence of rattlesnakes. He asked that any future recreational development at Bluffs Park exclude rattlesnakes, apparently unaware that the park is already home to the species, in addition to plenty of other wildlife.

Rattlesnakes can turn up almost anywhere. They even sometimes end up on the beach during winter storms, when canyon debris and reptile stowaways can be carried downstream onto the sand.

The presence of wildlands and wildlife is one of the things that draws people to the community and why our city is part of the largest urban national park in the world, the Santa Monica Mountains National Recreation Area. 

Rattlesnakes are part of that ecosystem and one of the natural hazards of living here. It's up to us to stay alert and on good terms with all our neighbors, on two feet, four feet, or no feet. I forgot the snake wrangler's advice the other day. It was an important wake-up call. Next time I head for the garden or the hiking trails I'll make sure to bring my brain.

Be safe out there.

Suzanne Guldimann
3 July 2015

The Malibu Post's backyard gopher snake goes about its business.

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