Snake Saviors

A group of UA researchers makes a yearly trek to capture and study a threatened rattler


Mention the word in most social functions, and two distinct camps quickly become apparent--those who want to make them disappear, rapidly and permanently, and those who acknowledge their place in the animal kingdom.

In the latter category are two Tucsonans (and lots of volunteers) who annually head for a huge pile of broken rock high up in the Chiricahua Mountains to spend several days chasing venomous snakes--in particular, Crotalus pricei, or twin-spotted rattlesnakes, found nowhere else in the United States but in four of Southern Arizona's mountain ranges.

Dave Prival put together the first rattlesnake roundup in 1997 at Barfoot Park, acknowledged as the world's most well-known collecting locality for this snake. "Although first described more than 100 years ago, this small-bodied pitviper has received little attention and gone largely unstudied," he wrote in a Journal of Herpetology article. Standing on a talus slope dressed in high-top boots and heavy-duty welding gloves, he adds: "No one else is studying them, and I know if I don't come up here and do it, nobody else will."

Why should that be important? As one of the smallest of Arizona's 11 species of rattlers (one more than 2 feet long would be a giant), twin-spots are morphologically similar to their ancient ancestors, threatened to the point of extirpation by illegal collection for pet trade, as well as global warming. To deter collectors, the snake has been placed under state protection. Global warming is another matter. "These snakes have moved up from lower elevations and now live at 8,000 feet and higher," says Prival. "They're probably one of the most 'at-risk' rattlesnakes as far as climate change goes, because they have nowhere else to go as global warming occurs."

What Prival and fellow researcher Mike Schroff try to do in each year's roundup is to capture enough (each averages approximately 20 specimens) to determine such things as population growth or decline, overall health, reproduction levels and food supply. This year's roundup conducted in late July produced a first: a clutch of five neonate twin-spotted rattlers less than a week old.

The capture process involves donning thick welders' gloves and trekking up a 60-degree slope made up completely of broken rock, looking and listening for sounds of rattling or rustling. "You have to use all your senses," Prival says. "We've done this enough times so we can hear the snake often before we see it, and that's good, because the contours of this rock pile don't allow much sight visualization." Even with these little guys, tail wagging occurs, and you can hear a small rattle. "You have only a few seconds to figure out where the rattle is coming from and dive on top of the noisemaker. By the time they start rattling at you, they're already headed back deep into their rock dens."

Says Schroff: "We bag the snake, noting its specific location on the slope, because when we have obtained complete data, we return it to its exact home."

Before the snake heads back home, the critter is weighed and measured, with a tag inserted for future bar-code recognition. With one researcher holding the snake in a plastic tube, another paints a color code on its rattle. The tag and rattle paint provide both an internal and external identification system for future recapture.

"With recaps," says Prival, "we can see how much it's grown, how much it has changed home location, whether it is pregnant or not."

While the snakes don't have the venomous impact of a large Mohave or a plump Western diamondback, twin-spots still have fangs, venom and a desire to be left alone. "I'd never seen any kind of rattlesnake when I first got to Arizona," says Prival, "but once it was demonstrated that you could put on tough close-meshed welding gloves, grab a twin-spotted rattler out of the rocks and get bitten without harm from their tiny fangs, my brain alarm shut off, and I started catching them."

"You have to have the process pretty well thought-out and planned," adds Schroff. "If you have a snake in your hand and don't know what to do with it next, there's a potential for problems to arise."

Despite that danger potential, Prival says with pride: "We've had more than a hundred people volunteer for this project, the vast majority of them without snake experience, and we've had no bites that required medical attention." (Poison and Drug Information Center records at the University of Arizona show that approximately half the reported snakebites throughout the state took place in Southern Arizona last year. The number of snakebite cases handled by the local center is more than at any other poison center in the country.)

The annual research roundup is conducted under the auspices of an Arizona Game and Fish Department scientific collecting permit, and a U.S. Forest Service special use permit. Emphasizing that while "this is basic, bottom-line, data," Prival feels a lot remains to be learned about the natural history of a species that nobody has ever studied in detail before. "The longer we do this, the more we learn about evolving trends of this component of the eco-system, a unique species that has evolved over millions of years. The baseline data we're obtaining now will be invaluable in coming decades to measure the impact of drought, fire, and the effects of global warming."

Fellow UA herpetological researcher Phil Rosen says that the vision of how we interact with nature in general--and snakes in particular--is changing. "Fear has turned to wonder and admiration, and hunting to kill is being replaced by hunting to observe, study, photograph and marvel," he says. "Whether the goal centers around wildlife management, fire control, recreational impact or growth of knowledge for yet unknown future needs, getting groups together in beautiful settings to study rare species seems to be a party with a future."

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