The headlights cutting through the dense dark of the New Mexico outback suddenly veer off the road, sending a beacon across a vast grassland. Andy Holycross jumps out of his Jeep, trots down the well-worn asphalt surface and scoops up a little toad that is invisible to all but those who know to look for its reflection.
"These guys stay underground most of the year and surface for a couple of weeks in the summer to mate," Holycross says, holding a squirming critter that finally wrestles free and leaps to the pavement.
Spotting toads on moonless nights while driving 40 miles per hour down country roads is one of Holycross' sidelines. His main line of work is rattlesnakes. Specifically, one snake. The threatened New Mexico ridgenose rattlesnake.
A 31-year-old graduate biology student at Arizona State University, Holycross is two years into a three-year field study of the snake in the isolated Animas Mountains of southwestern New Mexico. He is not alone in his fascination with Crotalus willardi obscurus.
Others have been willing to chuck everything they own and travel across the world to volunteer as field assistants in Holycross' project. They come despite the harsh conditions and lack of amenities Holycross emphasizes in advertisements placed in biology and herpetology journals and on the Internet.
The volunteers sleep in dirt on a waterless mountain for weeks and sometimes months. They forgo showers and baths. They are isolated from society for weeks on end. They eat oatmeal each morning, licking their plates after every meal to conserve water that is hauled up the mountain by a mule train. They risk the horrible pain that can be inflicted in a split second by the animal that has caught their fancy. The pay, if any, is negligible compared to the hours worked.
And even the most devoted ridgenose chasers have a hard time explaining the allure of these snakes, why they are worth this much sacrifice.
"They are a little like dragons without heads," Holycross says. "They are almost mythological."
Holycross turns his Jeep--adorned with a "Kill Your Television" bumper sticker--eastward, toward the peaks of Animas, and flashes his headlights at the mountains. Moments later, a light flashes back, 1,500 feet above the horizon, where four field workers at the base camp eagerly await the steaks and mail in Holycross' backpack.
Holycross heads down a four-wheel-drive ranch road toward the Animas Mountains, once the sacred grounds of the Casas Grandes and later the Apache Indians and now a mecca for those fascinated by rattlesnakes.
These mountains form the heart of one of America's last great open spaces--the Gray Ranch, which occupies one third of New Mexico's extreme southwest corner, an area called the "boot heel" for obvious geographic reasons. The 502-square-mile, privately owned ranch, ordinarily closed to the public, is a treasure-trove of biological diversity. Major ecosystems converge at the ranch--elements of the Sonoran and Chihuahuan deserts, the Rocky Mountains, the Great Plains and the Sierra Madre Occidental of Mexico--creating an explosion of wildlife supported by grasslands and mountain forests.
Mention the Gray Ranch to a herpetologist, and eyes light up as if you acquired the key to the Forbidden City. The ranch once provided habitat for the Mexican gray wolf, Mexican grizzlies and black-footed ferrets, all of which have been eliminated. But it remains home to at least four rattlesnake species--and the New Mexico ridgenose rattlesnake is the most mysterious of the lot.
Twenty jarring minutes down the ranch road, Holycross stops his Jeep at a dead end. With no time to waste, Holycross and greenhorn volunteer Steve Kolvek prepare their backpacks in darkness, except for light broadcast by lamps they wear on their heads.
A 21-year-old biology student at the University of Nebraska-Omaha, Kolvek has never been on a mountain. He mumbles about that last cigarette he smoked hours earlier, knowing that there will be no more for a month and that soon he will pay dearly for the habit. The men top off their packs with groceries, grab a couple cans of stove fuel, adjust their head lamps and start into a narrow, artificial tunnel of light that jags up a rocky riverbed and soon leads to a steep canyon that cuts into the heart of the mountain.
"What's this, Grasshopper?" Holycross asks the newest student to come to the mountain while pointing to a tree overhanging the trail. Kolvek's a quick study and correctly identifies the alligator juniper.
This question-and-answer game continues up the mountain trail Holycross has memorized. The climb starts to wear on Kolvek; he calls for a break. Plunging through the darkness makes it impossible to know how many more steps are ahead. But that's just as well.
Two hours later, an exhausted Kolvek and a still-jovial Holycross reach the base camp, which is nothing more than an old army tent and a couple of smaller, backpacking tents scattered across a plateau. The other researchers are asleep, but will awaken before dawn to prepare for another exhausting, invigorating day of tracking a shy, poisonous snake.
What researchers don't know about the New Mexico ridgenose rattlesnake dwarfs what they do. Holycross and his crew are trying to bridge the information gap in several ways.
First, they want to find out how many ridgenose rattlesnakes live in the Animas Mountains. The species was discovered by ranchers in 1953 and listed as threatened by the U.S. Fish and Wildlife Service in 1978, but no one has a good handle on the total ridgenose population. Researchers are catching and releasing the ridgenose in one canyon of the Animas Mountains, hoping to estimate the number of snakes living throughout the entire range.
"These things are listed as threatened, and we don't know if they deserve it or not," Holycross says. Before Holycross' project began, only 30 ridgenose had been found in the wild. But that total has been increased by more than fourfold during the field study, and during the first 20 days of July, the researchers caught, tagged and released 18 ridgenose rattlesnakes, along with some 20 other snakes.
Holycross also wants to determine whether the ridgenose rattlers in the Animas Mountains are genetically distinct from groups of New Mexico ridgenose rattlesnakes that live in two nearby mountain ranges--the Peloncillos to the west and the San Luis, to the south in Mexico.
The answers to these questions could provide insights for captive breeding of the snakes, if that becomes necessary.
"We are very interested in learning about the natural history, life history, habitat requirements, population size, and the genetics of this little rattlesnake," Holycross says.
But to study the ridgenose, you have to find them, and that doesn't come easy. Holycross estimates it takes five man-days to find one snake. Hence his heavy reliance on volunteers to literally beat the bushes looking for snakes.
The researchers, however, have acquired some ridgenose lifestyle information that helps in the search.
Although rattlesnakes have a reputation as ruthless predators that kill everything in sight, the ridgenose rattler is a shy creature that would rather hide than fight a predator as large as a human. The adult ridgenose is about 24 inches long and approximately as thick in diameter as the width of a quarter. Its name is derived from a distinctive pattern of scales across the snout.
The ridgenose generally live in mountain elevations above 6,000 feet and seem to particularly like rock slides, called taluses, where they can slip away from danger by diving into cracks. But the ridgenose also inhabit patches of thorny locust shrubs, where no human willingly goes. Often, the ridgenose is found in the talus, but within ten feet of neighboring locust.
These rattlesnakes eat only about a half-dozen times a year, but when hunger does strike, the ridgenose doesn't track its prey across rough terrain. Instead, the snake simply positions itself along a pathway where prey is likely to pass. Then, it waits--for days, if necessary--coiled and ready to strike when opportunity arises.
Maturing ridgenose rattlers tend to prefer eating the spiny mountain lizard; they strike and hold, letting venom kill the lizards before swallowing them.
Older snakes appear to fancy rodents and, sometimes, birds. Rodent hunting requires a different style of attack. The ridgenose strikes in a split second, injects its venom, releases the prey and lets it wander off to die. After waiting a few minutes, the snake uses a chemosensory organ located in the roof of its mouth, and its flicking tongue, to track the last steps of its prey. Upon locating the dead prey, the snake swallows it whole, head first.
The reproductive habits of ridgenose snakes are not fully understood. Typically, the male snake initiates mating through a series of overtures that includes flicking its tongue and rubbing against the female. The female must be receptive to this courtship; the male cannot insert its reproductive organs (it has two) unless the female physically opens herself to the male. Females typically deliver between four and eight babies and stay with them for about a week or until the young first shed their skin. After that, the snakes take off for destinations unknown.
"We don't know what happens to the young," Holycross says, although he suspects they spend much of their early life underground or beneath rocks.
If there is a secret to finding the ridgenose rattlesnake, young or old, it is patience.
"They are where you find them, when you find them," says camp cook James Sifert, an easygoing, quick-witted fellow who is a veteran of remote field camps, having spent a summer north of the Arctic Circle studying the musk ox.
A 26-year-old Canadian from Saskatoon, Saskatchewan, Sifert has been on the mountain for 18 days and submitted gracefully to its dry embrace. His curly, reddish-blond hair is dusted with dirt. His legs are caked with black dirt and crisscrossed by scratches. Clad in baggy olive shorts, a faded green tee shirt highlighted with a mix of sweat and grime, and wearing heavy, leather boots, Sifert now splits his attention between the water boiling on the three-burner Coleman stove inside the army tent and some thorns embedded in his hands.
Sifert pours rice into boiling water while Holycross starts a wood fire in the cooking ring behind the tent. He tosses rapidly thawing steaks on the grill, sending up an aroma that is sure to attract other members of the crew, out searching for snakes, back to base camp. This will be a rare, hearty lunch.
The fire pit is located on a ledge providing a view that stretches, seemingly, into eternity. A half-dozen succeeding mountain ranges extend across the northeastern horizon; they are separated by wide, dusty valleys. The landscape is unbroken by road or building. Ten-mile-long shadows cast by huge cumulus clouds--they will become powerful thunderheads that provide afternoon and evening entertainment--drift across the landscape. The only sounds are the cracklings of fire, occasional gusts of wind and scattered bird calls.
It doesn't take long before the other three members of the crew smell the grilling steaks and descend from a ring of peaks that tower 2,000 feet above the plateau. Empty canvas snake bags tell their story: It has been a fruitless, five-hour morning hunt. But spirits are high. The trek is as important as the capture.
"Just look as hard as you can and be real happy when you find one," Sifert explains.
A feast of cube steak and half-cooked rice is celebrated. Then comes a midafternoon siesta.
As the sun descends, the researchers emerge from resting spots beneath junipers and rock overhangs and quietly return to their mission: tracking snakes and setting rodent traps. First, though, there's a show. Nearby, a mountain spiny lizard, a favorite prey of the ridgenose rattler, captures a scorpion and slowly devours its meal, head first.
"I have never seen that before," a delighted Holycross says, watching the scorpion's tail disappear down the lizard's throat.
There are few things Holycross hasn't seen on this remote mountaintop. He's probably seen the ridgenose snake more often and more closely than any other researcher--perhaps a bit too closely. While he was examining a ridgenose last year, it bit him three times on his little finger. Holycross wasn't sure whether the snake had injected venom.
"I decided to wait and find out. So I ate dinner," he says.
Before long, his hand and arm swelled, and he immediately began hiking down the mountain. He ended up in a Tucson hospital for several days of antivenin treatment, an expensive ordeal that costs, on average, more than $15,000 and leaves a patient physically drained.
The snake bite hasn't deterred Holycross from pursuing the study, but it has made him more wary. "I don't want a second one," he says.
If Holycross has become more careful, that does not mean he will ever become a shrinking violet. Before bringing his current volunteers to the mountain, Holycross led them on a desert canyon hike up the narrows of Cibeque Creek, a Salt River tributary on the White Mountain Apache Indian Reservation in northeastern Arizona. Part of their initiation to desert living: a nighttime, 53-foot plunge down the inside of a waterfall.
"It seemed like it took forever to hit the water," Holycross says, grinning.
Now, to keep order among his troops, Holycross employs comedy and biting commentary, usually in a rapid-fire mix. Sometimes, he leaves his volunteers insulted and laughing at the same time. He jokingly calls himself "the dictator of Animas Mountain," but there is as much truth as joke to the title. But the stakes are high on Animas Mountain. The ASU biologist knows he has a rare opportunity to conduct research here; volunteers who don't buy into his program are ushered down the mountain.
That program includes an emphasis on learning about the ridgenose while inflicting as little impact on the snake and its environment as possible. It doesn't take much to disturb the habitat of the ridgenose rattlesnake. Amateur snake hunters, and those who illegally collect ridgenose for the black market, often wreak havoc on rattlesnake habitats by indiscriminately overturning rocks and logs in hopes of capturing the snakes.
"We don't look for them using those techniques," Holycross says.
Illegal collectors have strong financial incentives to disrupt habitats. The New Mexico ridgenose is a particularly hot item on the black market, fetching $5,000 or more from rabid Europeans seeking to round out their herpetological collections. In the United States, it is illegal to possess a ridgenose rattlesnake, dead or alive.
Because of the emphasis on habitat protection, the search for ridgenose rattlesnakes on Animas Mountain is time-consuming. Holycross' volunteers walk around the mountain, using long sticks to tap on rocks and logs and rustle through thickets. They look and listen, and when they get close, very close, the ridgenose rattlesnake usually makes its distinctive rattle--actually a subdued buzzing sound--as a warning to stay away.
Once a ridgenose is located, the trackers use 14-inch-long tweezers to grip the snake, usually about four inches below the base of its head.
Snakes found on flat ground or in woodlands are relatively easy catches: Grab the snake with the tweezers and quickly place it in a muslin bag, which is then tied closed.
Capturing snakes on the talus is far more challenging, especially when they decide to dive into crevices. Then, the tracker must carefully remove the rocks, sometimes rocks the size of small boulders, and pursue the snake.
Once a ridgenose is captured, the collector takes an array of measurements at the site. The time of the capture and the air temperature, surface temperature and soil temperature at the site are taken down. Humidity is tested. Cloud cover is noted. The altitude and exact longitude and latitude are recorded. The type of vegetation present and the position and movement of the snake when it was found are documented.
A yellow ribbon is used to mark the spot of capture, and the snake is transported down the mountain to the base camp. The hike down the mountain's steep peaks is tricky with both hands free. Holding onto a bag with a rattlesnake inside--a rattlesnake whose fangs can easily pierce the sack--greatly increases the drama of the descent.
When a snake is delivered to base camp, Holycross prepares his science table--located a few feet from the cookstove inside the army tent--for a detailed examination. Each of the captured ridgenose rattlesnakes is injected with a small magnetic identification chip that sits under its skin. The chip can be detected by a hand-held scanner if and when the snake is recaptured.
If the ridgenose is large enough, Holycross sedates the snake and implants a radio transmitter in its belly; the transmitter will last about four months. By mid-July, five snakes had been equipped with transmitters. After examination, the snakes are returned to the site where they were captured.
Tracking the ridgenose rattlesnake is a tedious operation that often leads the tracker onto unstable rock and into thorny locust thickets. But tracking is crucial to understanding a basic question nagging everyone working on the mountain.
How far do these snakes roam? The answer to the question will help determine whether the ridgenose rattlesnakes found on Animas Mountain evolved separately from nearby cousins.
It is up to 23-year-old Brian Fedorko, a wiry zoology and math student from Ohio Wesleyan University, to find out.
Although other snake hunters use simple, low-tech gear, Fedorko carries thousands of dollars of sensitive equipment in a small backpack. The equipment includes a radio receiver that picks up signals broadcast from transmitter-equipped snakes. Even with that equipment, Fedorko moves gracefully up the steep terrain with little strain. He's hiked miles every day for a month at altitudes ranging from 6,000 to 8,500 feet while tracking ridgenose.
Outside the base camp, the vegetation changes quickly as Fedorko climbs up a drainage crevice on the north face of the mountain. Oaks and conifers replace the desert plants, and a bit higher, a ponderosa forest and an aspen stand take hold. Scattered across the mountain face are patches of New Mexico locust, intermixed with the talus rock slides. Each area of talus has a name based on its shape or distinctive vegetation: Camel, Burnt Pine, Nose and Long.
As Fedorko approaches the site where he found a snake the previous day, he turns on the radio receiver and begins slowly sweeping an antenna above the landscape. The faster and louder the beeps coming from his receiver, the closer the snake. Fedorko's ear is finely tuned to the tenor of each beep, and he quickly zeroes in on a snake's likely location. At that point, Fedorko's eyes take over. Sometimes a snake is readily seen. Other times, 30 minutes of searching turn up nothing; the snake is underground or beneath a rock.
On this July morning, three of the ridgenose rattlesnakes are in the same area as the day before. The other two have moved about five meters.
The search for the latter two--which researchers have named Killer and Spaz--is particularly challenging because they are moving through thick stands of thorny locust. The day before, Spaz startled Fedorko, who's still a little edgy.
"Yesterday I was about two meters away and didn't see him when he jumped straight up in the air and landed in a shrub next to me," Fedorko says. "That kind of worries you when you're walking through this shit."
But Fedorko keeps pressing into the locust thicket until he finds Spaz resting on a bed of leaves beneath a small boulder. The snake pulls into a coil, but doesn't shake its rattle. The gray rattler's color blends perfectly with the surrounding rocks, making it difficult to see. But there is no doubt it sees Fedorko. Its eyes are locked on him as he takes an array of measurements at the site.
Fedorko doesn't see the snake's stare as a threat.
"They are very docile," Fedorko says. "Not that I would go around free-handling them or anything."
But the snake, Fedorko explains, prefers to conserve its venom for hunting lizards, rodents and birds--animals small enough to subdue and eat. The ridgenose avoids human contact, if at all possible. "They usually strike as a last resort," he says.
Fedorko is in his second season tracking ridgenose rattlesnakes. Last year he spent 13 days alone on the mountain conducting research--not only on the snakes, but on his ability to deal with solitude.
"It didn't really hit me until the third day that I wasn't going to see anyone for another ten days," he says. "After a while, you accept the fact you're going to be here. Then it's not so bad."
In fact, it can be great. The solitude provided the opportunity for close observation. Fedorko says he was able to repeatedly approach within two feet, and then photograph, a pair of endangered Mexican spotted owls perched on a tree limb.
Fedorko's close encounters with ridgenose rattlesnakes and spotted owls make any hardships seem trivial.
"You remember every place you caught a snake," Fedorko says. "I remember when I saw the owls. Every place has a story."
Most of the volunteers who come to Animas Mountains become enamored with the place.
"Some people come up here and they are unleashed," Holycross explains. "You can see it in their eyes."
The thrill can be--well--visceral. One volunteer became so enthralled with the mountains that, according to his journal, he ascended one of its highest peaks and "threw his seed to the wind."
A thunderstorm that earlier kicked up a giant dust storm in the valley drifts over the campsite as the sun sets. The rain starts, stops, begins again, tapers off and finally unleashes a steady torrent. The main pole holding up the 150-pound army tent, reinforced with duct tape, sways slightly in the gusty winds. A small transistor radio hangs by a strap from the tent's ceiling, eking out a surprising, eclectic set of tunes from Silver City, New Mexico's "only radio station."
A Coleman lantern casts a two-mantle light across the dirt floor.
The mood is quiet, almost subdued.
Lawrence Smith leans back on a blue nylon cot and thumbs a book about the Animas Mountains. The 35-year-old has an undergraduate degree from Oxford University and a doctorate in ecological entomology from Britain's Reading University.
Before long, the lure of the rattlesnake sneaked into his consciousness. He quit a corporate job developing pesticide-resistant plants, packed his worldly possessions into two knapsacks and moved from London to the Animas Mountains to study the ridgenose.
For his first couple weeks at the site, Smith slept in a nearby cave--a cave that was home last winter to a black bear.
Smith says his sudden shift from office to bear cave wasn't as unsettling as it might seem. His life's choices are motivated by his desire to learn. Beyond that, he says, there are few restraints.
"Money," explains Smith, whose appearance is steadily becoming similar to the bear whose cave he borrowed, "is not a concern of mine."
Across the tent, Fedorko appears lost in thought. His dark-haired head hangs between drooped shoulders. His goatee appears elongated by the frown across his face. He's disengaged from the evening banter about snakes, sports, music and women. Not even Holycross' needling can break Fedorko of his funk.
It's uncertain why he's got the blues. But earlier in the day, Holycross lashed out at the field assistant for not following precise instructions for one of the 20 measurements that must be taken each time he locates a snake with the radio transmitter.
On top of that, one of the snakes Fedorko had captured died following a mix-up. Luckily, it wasn't one of the threatened ridgenose. But here, the death of any animal is not taken lightly.
The rain continues throughout the night.
Dawn brings great hope. The rainfall should stir up the ridgenose snakes, increasing the odds of a capture. The glumness of the evening before is replaced with anticipation.
Sifert and Smith take advantage of the puddles of rain captured on the deeply pitted surface of nearby rocks and rinse the grime from their bodies.
"There's only so much those Baby Wipes can get off," Smith says, splashing water across his face. "This is lovely after having been up here for 20 days."
Kolvek and Bill Richardson decide to hike to the top of the peaks, searching for ridgenose rattlesnakes along the way. Richardson, a 22-year-old graduate of Stetson University in Deland, Florida, strikes an air of formality as he begins the search. His insistence on wearing snake chaps irritates others in the crew, who see the garb as an unnecessary precaution, an indication that Richardson is not at ease with ridgenose rattlers. Nevertheless, Richardson has been responsible for seven of the 17 ridgenose captured so far this summer and seems to have an instinct of where to find them.
As the men approach the 8,500-foot summit, Richardson discovers yet another ridgenose rattlesnake, this one moving across open ground beneath a stand of ponderosa.
"That makes up for five days of searching," he says with a clipped inflection. Richardson carefully picks up the snake with his giant tweezers and transfers it to the canvas snake bag.
Back at the base camp, Richardson's latest capture livens up lunchtime.
Sifert is mixing tuna fish and noodles on the stove. A few feet away, Fedorko is coaxing the ridgenose into a clear, three-foot-long plastic tube, where measurements and observations can be safely taken.
The snake obliges, pushing its head inside the tube. The snake then squirms, pulling its body into the tube as well. Why the snakes fall for this trick, no one can say. But they do, every time.
Fedorko gently pulls the snake's tail out of the tube and begins counting its scales, checking its sex and measuring its rattle. He gives the snake a squeeze, forcing a stream of feces to emerge. The donation will be analyzed to determine what the snake has eaten. Blood is removed for later DNA testing, and the tiny identification tag--called a passive integrated transponder--is injected.
Holycross takes a turn examining the snake, while dancing to the radio belting out Wilson Pickett's "Who's Making Love to Your Old Lady." Holycross repeats the refrain, directing the question at Fedorko, who has a girlfriend back home in Ohio.
Before he can reply, Sifert interjects, "We know six guys who aren't." There is a round of rude laughter.
Moments later, Holycross spies a lizard outside the tent door and dispatches Smith to catch the critter. Smith scoots out the door with a long stick with a wire noose attached.
"I'm going lizard fishing," he says. But the lizard gets away.
Sifert, meanwhile, begins passing out heavy plates of tuna and noodles. The ridgenose rattlesnake, now released from the plastic tube, slithers around on the dirt floor. Lunch is enjoyed while a venomous serpent wiggles across the dirt within a yard of a dozen feet.
Everyone is delighted.