Guess we may be getting a shirt tail cousin to the mojave Gr

[Butcheragain]

Snakebit: Southern California sees a rise in extratoxic venom
Humans may have paved the way for the Southern Pacific rattlesnake
By Michael Tennesen

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Rapid muscle twitching, as if a person had snakes crawling under the skin, is the telltale sign to Roy Johnson that the Southern Pacific rattlesnake has struck. On occasion, this symptom can progress to difficult breathing, coma and death. This snake's bite is one of the few to induce neurological symptoms, in contrast to most other rattlesnake bites, which initially produce swelling and bruising around the wound, notes Johnson, a physician in Palomar, Calif., who has treated some 700 snakebite cases. Increasingly, the proportion of rattlesnake bites in southern California are skewing to those like the more deadly Southern Pacific species, and scientists are not sure why.

Every year the Centers for Disease Control and Prevention logs 7,000 reports of snakebites in the U.S., which lead to about 15 deaths. Roughly 25 percent of the survivors incur some permanent damage. In southern California, reports from area hospitals and medical centers show a spike in serious bites the facilities say that, where they formerly saw patients with severe neurological symptoms once every two to three years, they now see several of these types of envenomations every year.

Johnson, for one, suspects that humans themselves are to blame for the increase. Most rattlesnakes warn off potential predators by shaking their noisy tails that is what the red rattlesnake and the speckled rattlesnake, southern California's other two dominant coastal species, tend to do. But the noise also makes the reptiles more likely to end up on the killing end of a shovel if the threat is human. In contrast, Southern Pacific rattlesnakes are more apt to lay low or move away than hiss and rattle when confronted, a strategy that may boost their chances of surviving, Johnson says. He speculates that by clubbing its competitors, humans have paved the way for the Southern Pacific to move into new areas. That animal "is adapting to human habitats much like the coyote whether we like it or not," John son remarks.

The rising incidence of supertoxic bite cases could also reflect a change in the species' venom. To predigest their prey, most rattlers produce so-called cytotoxins and hemotoxins, which damage tissue and disrupt blood clotting. But the Southern Pacific also produces a neurotoxin, which is more serious because it quickly affects breathing and muscle control. Anecdotal reports suggest that the snake's venom contains more neurotoxin than it did a few years ago. Richard Dart, director of the Rocky Mountain Poison and Drug Center in Denver, does not rule out that the species could have made its venom more toxic, perhaps by crossbreeding with the more deadly, desert-dwelling Mojave green rattlesnake or by turning on dormant genes developed over time in response to more resistant prey.

The amount of neurotoxin is indeed dramatic compared with the creature's close cousin, the Northern Pacific rattler. This species preys on ground and rock squirrels, which by six weeks of age develop a natural resistance to withstand a full envenomation, suggests research at the University of California, Davis. The Southern variety, however, has enough neurotoxin to overcome any such natural resistance, says biologist William Hayes of Loma Linda University. "Southern Pacifics have no problem getting lots of squirrels."

Still, Hayes does not believe that the rattler's venom has become more toxic. Rather he thinks that people are becoming less tolerant of snake venom, perhaps because of "pollution weakening human lungs and the immune system."

Sean Bush, a treating physician at Loma Linda University Medical Center, says that the Southern Pacific is definitely the "people-biting snake in California" and attributes the increase in incidents to humans encroaching on the animal's coastal and mountain habitat. We are, Bush says, "only now learning how potent and varied rattlesnake venom can be."


http://www.sciam.com/article.cfm?id=sna ... california


http://www.sciam.com/article.cfm?id=sna ... california

[Jerry Feldner]

I'm not so sure about your contention.
"Anecdotal reports suggest that the snake's venom contains more neurotoxin than it did a few years ago." That's what these are. Anecdotal reports. I have been in contact with Dr. Hayes and Dr. Bush repeatedly over the years and neither one admits to having been quoted correctly on numerous occasions. Also, Dr. Wolfgang Wuster of Bangor Univ in Wales and Dr. Brian Greig Fry (mentioned in the article) do not support the idea of a sudden rise in snake venom toxicity or makeup. Do a little research on Tennesen. I did. Even though he graduated from the right university (Go BRUINS) I have not been able to discover in what field. He appears to be a writer (could he have majored in Journalism?) who has found a niche in science writing.
I do not believe that toxicity or venom makeup can change drastically from one snake generation to another. Of course, there are a number of rattlesnakes which have different venom fractions as a juvenile than they do as adults and this phenomenon is well-documented. In most cases, it has to do with a change in prey items as the snake grows and is more able to down larger prey.
I reject Tennesen's (and your) idea that Mojaves (not necessarily green - I know where there are pink mojaves and here in AZ there are few green populations) are breeding with Southern Pacifics and creating a snake with super strong venom.

[Sandman]

"In contrast, Southern Pacific rattlesnakes are more apt to lay low or move away than hiss and rattle when confronted, a strategy that may boost their chances of surviving, Johnson says. He speculates that by clubbing its competitors, humans have paved the way for the Southern Pacific to move into new areas. That animal "is adapting to human habitats much like the coyote whether we like it or not," John son remarks."


I live in an area where the range of several species overlaps. Over the years, i have known 3 different friends who have been bitten. 3 bites were from Southern Pacific Rattlesnakes that struck first, and then rattled as they went into defensive mode. All three individuals were hiking in this area wearing sandals. I almost stepped on a coiled Southern Pacific one morning on the trail and it never rattled. Since I have this habit of watching the ground ahead of me, I avoided a bite. I was wearing good boots however and always do when hiking, no matter how hot it is.

The other friend who got bit was nailed by a sidewinder that he attemped to catch while drunk. It was a nasty bite and he came close to losing his hand. DUH!

Working in the ICU, I had to administer antivenem one time. It was a copperhead bite on the East Coast. Again, the individual attempted to catch the snake and he did. He brough it with him to the ER alive in an igloo cooler! It was a good bite and the swelling extended up his arm to the chest area. I gave him his second dose and watched him close for anaphalxesis.

Snakes are very interesting. Sometimes I will just sit and watch a rattler at a distance for a while. If you sit still, they resume a more natural position and move along into whatever cover is around. They dont seem aggressive unless provoked.

The western diamondbacks are common around here as well. They seem like they are quick to rattle. Mojave greens look like they are just plain evil. They are commonly found down in the flats and washes. With all of them, I just give em a wide berth and hope they eat alot of rodents in their lifetime.

I'm not a herper but I appriciate all of the expertise shared here on DUSA. Education is a good thing! Thanks guys.

[Jerry Feldner]

Let me get this straight. You mentioned that there are three spp of rattler that live in your area. Then you mentioned several different ones, some of which coexist in the same geographical range and some which don't. Since you are in CA, let me clue you in. Western Diamondbacks, (Crotalus atrox) may live in the same area as Sidewinders, (C. cerastes ssp) and the Mojave (C. s. scutulatus), however, none of them are sympatric with Southern Pacifics (C. oreganus helleri).


Take a look at the maps accompanying these pages: http://www.californiaherps.com/snakes/p ... atrox.html

http://www.californiaherps.com/snakes/p ... astes.html

http://www.californiaherps.com/snakes/p ... latus.html

http://www.californiaherps.com/snakes/p ... lleri.html

Of course, anyone who goes hiking in sandals in known rattlesnake territory deserves to be bitten.

[Butcheragain]

I'm not so sure about your contention.

Damn, Jerry I thought we resolved our differences some 15 yrs ago!
There was no contention as your thinking! Just figured I would pass on some bit of information I came across on the net! Haven't got the time for confrontation right now but if you want to rehash old feelings, then have at it ole buddie! But I myself have better things to do at the moment!!

[reptilist]

No need to get all bowed up there Butcher. Jerry sometimes comes across a little rough, but he isn't trying to pick a fight. As for having a "confrontation"; that won't be happening on this message board anymore.