Retired American Airlines pilot Barry Martin has been called the best animal tracker in San Diego County. I asked how he first came to be interested in this arcane discipline.

A lanky athlete with probing eyes and a cleft in his chin, the 54-year-old Martin told me his interest was born when he was about 9. His family lived on a hillside overlooking Lake Sammamish, east of Seattle. Their house stood in a clearing surrounded by forest. Not long after the family moved in, Martin and his brother were roused from sleep by their sister, who whispered that two deer were in their back yard. Martin remembers rushing downstairs and sitting beside the sliding glass door that faced the rear of the house. It was dark, but he could make out shapes of a white-tailed doe and her yearling, nibbling grass near the family's patio. The sky grew lighter, and the sun began to rise. The doe looked up, and she and the fawn began to head for the woods. But she stopped and turned to look straight at Martin. He says it felt as if she were asking him, "Well? Are you coming?"

Martin says when he got home from school, he looked for the trail the deer had followed. "As I walked from the clearing into the woods, there was this total change. It had been raining, and although it had cleared up a bit, it was still drippy, and the silence was incredible -- like walking into a cathedral. But I just stood there for the longest time and soaked it in, and suddenly something shifted. It was like I had been welcomed and drawn in further."

He says he realized that the marks on the ground were the tracks of the deer he'd seen that morning. He could see how the doe's were larger and the yearling's were smaller. "I could follow these tracks and figure out what they were doing during that day! That began my secret life."

That year Martin spent as much time as he could in the woods. "I tried to figure out what was going on, what animals were there." He endeavored to follow the tracks he encountered. He'd sit for hours in the top of a pine tree, observing the world below him. His family then moved several times, but "I would always seek out the natural places." He studied raccoon tracks in the almond and walnut orchards near Modesto.

After college, he became a Navy pilot and flew on active duty for seven years. In 1985 he was hired by American Airlines. Based in San Diego, he and his family settled in Rancho Peñasquitos in 1987. He says it took him only a few days to discover how close he was to one of the entrances of Los Peñasquitos Canyon Preserve, the city's 3200-acre nature park that stretches from Interstate 5 to Interstate 15. He began venturing into it.

Martin says one day he brought along his daughter, who was about 12. As the two of them wandered into a riparian area, Martin marveled at the animal tracks he was seeing: coyote, bobcat, raccoon. Father and daughter came upon the 170-year-old adobe ranchhouse that serves as the preserve headquarters, and Martin began chatting with a couple of rangers. When they told him they were setting up a volunteer patrol group, the pilot signed up.

Around this time, Martin learned about the work of renowned tracker Tom Brown Jr. Two years older than Martin, Brown grew up on the edge of the Pine Barrens wilderness in New Jersey. A few months after his seventh birthday, he met his best friend's grandfather, an 83-year-old Apache elder named Stalking Wolf. "His dress, his mannerisms, and everything about him exuded intense and limitless knowledge," Brown has written of the Indian: "To me he was the spirit of the wilderness and possessed all the knowledge I could ever hope for."

After Stalking Wolf's death in 1967, Brown reportedly spent another ten years perfecting his wilderness skills, and by the late 1970s law-enforcement agencies called him for help in finding missing persons and fugitives. In 2003, some of those skills were fictionalized in a movie called The Hunted starring Tommy Lee Jones and Benicio Del Toro. Brown founded a tracker school in 1978 in New Jersey. The school has instructed thousands of students in tracking, camouflage, and spiritual healing. After reading several of Brown's 16 books, Martin journeyed to New Jersey for instruction. He says he found Brown to be "an interesting character. I think as a sort of a defense mechanism he comes across as being almost mysterious and moody and deep." Over the next few years Martin took eight of the classes, including both technique and philosophy.

Martin's studies of Peñasquitos Canyon were also unfolding. "I decided, well, maybe I need some help with this." He wrote an article for the Friends of Peñasquitos Canyon Preserve newsletter, soliciting volunteers to help him with an animal survey. "Back then, development was threatening to totally cut off Peñasquitos Preserve from the adjoining open-space areas," he recalls. He thought a survey of the wildlife could help prove that the preserve was a healthy ecosystem and show that "one of the reasons it was healthy was that it was connected to other areas."

Fifty volunteers responded to Martin's call, and he condensed Brown's week-long "standard" class into a weekend training session. From that group of 50, "We eventually derived the Peñasquitos Canyon Preserve Tracking Team." Since then, additional teams have been organized at Mt. Woodson in Ramona, Preserve Calavera in Carlsbad, Rose Canyon, Daley Ranch, Mission Trails Regional Park, Blue Sky Ecological Reserve, Box Canyon, and Volcan Mountain.

The San Diego volunteers cover 50 or so "transects" identified by the San Diego Tracking Team, the umbrella group that coordinates all the individual tracking teams' activities. "For our purposes, a transect is a trail," Martin explains. "We'll take an established trail, and at specific intervals we'll walk down it." Trackers record tracks, animal droppings (known as scat), and other evidence of the animals' presence. "If you have a little side trail that runs into that trail, you go down it approximately 10 or 15 feet...to see what animals are using it."

Teams cover each transect two to four times a year. I joined a 7:00 a.m. tracking excursion through Lopez Canyon, the large side canyon that branches off the western end of Los Peñasquitos Canyon. In a parking lot off Sorrento Valley Boulevard, I met Uli Burgin. A quick-moving woman in her early 70s, she has gnomish features, lively blue eyes, and glossy brown hair bobbed short. Born in Switzerland, Burgin moved to San Diego in 1962, shortly after getting a Ph.D. in zoology. She started leading surveys in 1997 and took over the Lopez Canyon transect about five years later.

Two more volunteers joined us: another older woman named Vernie McGowan, who learned about tracking at Torrey Pines State Park, where she was working as a docent, and Gary Seiser, a lawyer for the county who heard about Tom Brown's tracking school when the subject came up in a writing class. Seiser took Brown's standard class in New Jersey in the spring of 2004.

Burgin pulled out the form that all the wildlife survey teams use. Each transect is divided into sections, and for each section transect leaders record tracking conditions, topography (flat, sloping, etc.), and habitat (chamise chaparral, oak riparian, grassland, or 1 of 11 other possibilities). They note evidence for the presence of 14 species of animals: black bear, bobcat, coyote, gray fox, mule deer, pack rats (a.k.a. wood rats), opossum, raccoon, badger, black-tailed jackrabbit, mountain lion, long-tailed weasel, ringtails, and roadrunner. (The presence of skunks, cottontails, ground squirrels, and small rodents is recorded though not extensively documented.) Because other local groups conduct surveys of reptiles and birds, the tracking teams have decided to concentrate on the mammals. According to Martin, "If you've got a wide cross-section of mammals, that is in and of itself a good indicator of the health of the overall ecosystem."

Burgin led our group to the start of the transect, next to a kiosk bearing information about the preserve. A few dozen feet down the trail, she stopped to scrutinize a sharp-edged teardrop-shaped impression that was little more than two inches long -- the hoofprint of a mule deer. The challenge, Burgin explained, was to decipher whether it was more than two weeks old, one of the facts to be recorded on the survey form. Nimble as a teenager, she dropped to all fours and blew on it to disperse dust and other debris. Based upon the hardness of the ground, she marked it down on her sheet as "historic."

Another problem, Burgin told me, was to distinguish coyote tracks (which the survey teams record) from the pawprints of dogs (which they ignore). Dogs are everyday visitors in the preserve, and the basic shape of both species' tracks -- an oval composed of two forward-pointed inner toes, two outward-canted outer toes, and a triangular heel pad -- are so similar as to confound beginning trackers. But differences can be discerned. As we came upon marks left by both types of animals, Burgin, McGowan, and Seiser showed me how the dog tracks tend to be more splayed. They almost always include little holes made by the animals' claws. Although coyotes have claws, more often than not, theirs don't leave a mark upon the ground. In the center of many coyote tracks, you can discern more of a mound, as if the muscle tension in the animal's toes had squeezed the dirt between them into the shape of a little hummock. "The dog tracks tend to wander all over the path," Burgin added. Coyotes meander less.

We moved past thick stands of mule fat and goldenbush, and Burgin halted to study another mark. The overall shape resembled that of a deer's track, but somehow it didn't look right to the transect leader. "Always what I do when I'm not quite sure is to look for more," she declared. "All of us have been tricked -- and keep getting tricked -- by shoe patterns." In this instance, the three trackers discovered another set of fresh deer tracks farther down the path that confirmed the nature of the first track, so Burgin recorded this animal on her sheet, then resumed moving forward, eyes trained downward.

"What's this?" McGowan asked about a delicate tangle of lines snaking through one patch of damp ground. Burgin and Seiser joined her to puzzle over it, but no one could identify the marks, so the group moved on. "We have mystery tracks that we can never solve," Burgin said. A moment later, Burgin and Seiser's attention was engaged by a second set of deer tracks when McGowan's voice rang out. She announced that she had found the perpetrator of "that weirdo track" -- a beetle whose shell was creating more of the twisting pattern as the tracker looked on.

Sycamore leaves -- leathery copper on one side and furry tan on the other -- littered the trail in places, obscuring our view of the dirt and making it harder to see tracks. We passed through clear sections, too, where no animals seemed to have trod. "Some trails the animals use, and some they don't," Burgin said with a shrug. In other places, though, so many deer tracks clustered that, in my mind's eye, a herd rose up and took shape. It struck me that if I had hiked this trail the day before, all these marks would have been too chaotic to catch my attention. But now I was spotting the deer tracks with ease.

More than tracks conjured up the animals' presence. Their droppings took on significance. In some of the scat, Burgin called my attention to a graininess that she said betrayed the kibble-based diets of domestic dogs. When she used the tip of her trekking poke to break open the twisted and pointy-ended piles of what she said was coyote scat, we could see tufts of fur and bone fragments. "Sometimes you see gopher teeth," someone commented.

Burgin cautioned that coyote scat could look anomalous when it had been rained on or run over, and a pile that we encountered under some oak trees confirmed her words. When Burgin poked at it, it seemed to separate into segments, a characteristic of the leavings of bobcats and mountain lions. "But it has so much bone," the transect leader noted, sounding dubious. "I'm not used to seeing that much bone in bobcat scat." She drew closer to it and sniffed and judged it to be coyote.

Burgin says she once found a deposit of what she thought was mountain lion scat next to one of the streams on one of the Lopez Canyon transects. The dark, blunt-ended chunks were broken into segments reminiscent of thick Tootsie Rolls, typical of the local lions' droppings. But since cougars are rare within the preserve, Burgin bagged the fecal material and took it in for review by some of the most experienced trackers in the group. They confirmed her call.

Burgin's group didn't find signs of mountain lion or bobcat on the morning that I accompanied them, but they did come across a delicate seed-filled pile of raccoon scat. Burgin thought that a fox had produced the thin, dark excrement that we found amidst a drift of fallen sycamore leaves. However, the volume of that pile seemed greater than a fox might be likely to leave, so she scraped it into a plastic bag and vowed to get additional opinions.

When I saw her a few days later, she told me, laughing, that she had heard several conflicting pronouncements, and each person she had asked seemed confident he was accurate. "It happens," she said. "These are open-ended things. When it's inconclusive," she added, "I usually don't write it down."

Ann Hunt is another local tracker who seems ill at ease with imprecision. Hunt spent her career working as a consultant for IBM, and she projects an attitude businesslike and scientific when she's leading a transect, as she did on Mt. Woodson a few days before the winter solstice. The outing had been delayed by rain in the preceding weeks. It would be one of the last of the tracking teams' fall survey efforts.

Mt. Woodson is the mountain that looms over the north side of Highway 67 between Poway and Ramona. A community has taken shape on the mountain's lower northern slopes over the last 10-15 years, and Hunt's house is located there. But most of the mountain has been preserved as open space, including the spot where Hunt's group assembled, higher up the northern side. The participants included a gray-haired woman named Betsy Brack, who learned about the tracking group through the Sierra Club in the spring of 2004 and took the one-day introductory session. "Ever since I was a kid, I had wondered what all the tracks were and how you tell one thing from another." Poway resident Tylene Williford had been involved with the tracking team for about 2 years, by her estimate. The fourth member of the group, Cindy Rozell, had come to San Diego County from Oklahoma to care for her ailing grandfather and heard about the transect training. She then took three naturalist classes. "This is what I'm going to do for the rest of my life." If she couldn't find a tracking group when she returned to her home state, she planned to start one. "It's a passion for me. It's all about the circle of life. And it's so important!"

Hunt came armed on this morning with a list of 26 GPS coordinates. These corresponded with descriptions of wood rat nests along the transect that had been compiled by previous groups. "We're supposed to be recording them every time," Hunt explained.

The tracking conditions she judged to be "poor." A few weeks had passed since the last heavy rain, and the decomposed granite underfoot had dried to an unyielding temper. By late summer, the ground would slough off layers of dust that would make for excellent tracking. "Dust is our friend," Hunt commented. But for the present, the group would probably have to detect the presence of the animals living here through their dung, she said.

Almost immediately, one large deposit snagged Hunt's attention, but when she poked at it with her walking stick, she lost interest. "There's no fur in it. Not a stitch of fur. That was a dog masquerading as a mountain lion."

A little farther along, the group identified a pile of twisty black ropy material. "Now that looks like fox," someone said.

Brack took in the sight of several specimens up ahead and exclaimed, "My goodness! This is scat central!"

To some of these deposits, Hunt applied what she called "the roll test," loosening sections of the feces under the treads of her aging gray Sauconys. "Barry tends to leave scat alone out of respect to the animal. I don't," she said. One gray-colored sample exuded a cloud of fine powdery dust when she tapped it underfoot. "That's bloodmeal," she said. "It means the animal ate a lot of blood." Fur was present in that sample, along with tiny chunks of bone. All this made the transect leader feel confident that a bobcat had produced it. "With presence of bunny."

"Digested bunny," Williford clarified.

Other members identified nearby fox and coyote scat, but three strands of dark brown fecal material puzzled Williford. She pulled out a pocket field guide that Martin has compiled for the trackers, flipped through the pages, then declared, "Ah-ha! Longtail weasel! Looks just like it, doesn't it?" she asked, comparing the sketch to the objects in front of her. The presence of weasel excrement was hardly surprising, according to Hunt. "Weasels have been seen here. Live ones -- raising their young in people's yards."

In a thicket of oak trees and chaparral, the group came upon an even more abundant concentration of scat in varying shades of gray and charcoal. "It's a bobcat latrine," Hunt pronounced. Not only bobcats but other animals, including coyotes and raccoons, sometimes choose to defecate in the same areas as their fellows. "In mating season, they can do it as a sign of marking," Hunt says. The range of colors and textures resulted as the material aged. After some study, Hunt decided seven separate specimens were present. "You look at the colors, the age, what looks like it belongs together, the freshness, the quantity. And where it's located." Even considering all those factors, "It's still a judgment call. And I'd rather under-call it than over-call it."

Scat was remarkable, the women concurred. Rozell talked about seeing skunk droppings crammed with the remains of insects back in Oklahoma. Williford reminisced about coyote scat loaded with snake scales that she had once encountered.

Hunt's group did finally find more than droppings. They came across scraped areas where skunks had pawed the ground in search of grubs and insects. Not far from a natural stream, they spotted the first of the pack-rat nests, a dome-shaped collection of twigs and other debris, set back from the path, amidst tree branches and shoots of poison oak.

After almost two hours, the trackers emerged from the woods and approached the back yards of a line of large, well-maintained houses. To the northeast we could see the Ramona Grasslands, "Eight thousand acres of some of the last pristine grassland left in Southern California," Hunt said. The Santa Maria Creek runs through the area, which hosts a small number of grazing cattle, along with several endangered species. Although threatened by development pressure, a portion of the grasslands was recently acquired by the Nature Conservancy, and the San Diego Tracking Team launched a new transect there at the beginning of the summer.

A few steps farther down the trail, the first good tracking conditions of the day drew Hunt's gaze away from the grasslands. Mountain bikes had roughened up the surface, and on the sandy ground, Hunt soon spotted a bobcat track: four oval toe pads pointed straight ahead above a deeply lobed heel pad. At first it seemed to be the only track from this animal that had survived. But a few minutes later, Hunt exclaimed as another bobcat track about a foot away emerged from the jumble of visual stimuli to register on her consciousness. As soon as she pointed it out, everyone else in the group could see it.

By the end of the morning, Hunt had recorded evidence for five of the animals on the survey list: coyote, bobcat, gray fox, pack rat, and weasel. One of the jobs that Hunt performs for the tracking team is to collect forms from survey leaders, then send them to whichever volunteer is entering all the data into the group's database.

Martin says that for a long time the San Diego Tracking Team avoided analyzing the results of its animal surveys. Then, in June of 2004, the organization received the first of three Blaster Grants offered through the San Diego Foundation. The team has been using the roughly $53,000 to pay San Diego State University graduate students like Shea Valero to help make sense of all the survey findings. A third-generation San Diego County resident, Valero told me she had found at least a couple of clear trends.

"We have more raccoons in winter, and we have more possums in summer. It might be an activity level. It might be migration into a certain area." Valero said coyotes appear to decrease in summertime. "I'm not sure where they go, but they drop off. That was seen in at least 80 percent of the transects."

"And then the deer are interesting," she continued. "Their numbers decrease in winter. They drop more in spring and in summer, and then they boom in the fall. In the fall they're going to move around more because they're coming off an extended dry season. And they're going to range out farther to see if they can find available food resources. A lot of times that's when you'll see them in grassy areas in parks. Or where people have built right up to the edges of open-space areas, they'll be browsing on succulent growth that spills out from the back yards."

Valero said she hadn't detected unambiguous correlations between the seasons and the evidence left by gray fox, bobcat, cougars, and some of the other species. "But blacktail jackrabbits appear to increase in spring and summer and drop off in fall and winter."

When she looked at how the survey results have varied throughout the years, Valero found the year 2002 to be something of a high-water mark. She said the evidence of bobcats, coyotes, deer, raccoon, and fox tended to hold steady or increase from 1996 through 2002 but then decreased in 2003 and 2004. (For opossums the numbers began to decline one year earlier.) The exceptions to this rule were cougars, weasels, and wood rats, whose presence in the surveys has held more or less steady since the tracking teams began functioning. Evidence of black-tailed jackrabbits and roadrunners tends to be uncommon, Valero said, but for both species it also spiked in 2002, then dropped. Badgers were only noted in 1999 and 2001, while ringtails (a raccoon relative that's also known as a miner's cat) only showed up in the 2001 and 2003 surveys. "But in 2003 there were a bunch." Valero acknowledged that this could be because the trackers got more proficient at recognizing ringtail signs that year.

Expanding the number of survey areas is a major goal of the San Diego Tracking Team, according to Martin. Last year the umbrella organization helped to create the teams in Blue Sky Ecological Reserve, Box Canyon, and Volcan Mountain, and this year the trackers have vowed to set up new groups in more areas. In the long run, Martin and the other leaders want to establish transects in all the key wildlife corridors of the county's open-space preserve system.

That system, which includes the Multiple Species Conservation Program covering the southwestern portion of the county and the Multiple Habitat Conservation Program in the northwestern portion, has involved "a total paradigm shift," according to Jerre Stallcup of the local Conservation Biology Institute. The idea behind these programs, which were conceived in the late 1980s, was to set aside areas of interconnected open space to preserve native plants and animals, while streamlining development outside those areas. The federal government would no longer police developers with regard to endangered species, but local authorities would make sure development met state and federal regulations. Environmentalists and developers would have to make concessions, but both could gain much more than they would otherwise.

For six years, a 30-member working group wrangled over the Multiple Species Conservation Program. "It was really a stressful time for a lot of people," recalls Stallcup. "Some went through divorces and heart attacks. There were people in the hospital."

A plan for implementing the preserves was developed and approved by the San Diego City Council and the San Diego County Board of Supervisors in 1997, and SANDAG (the San Diego Association of Governments) signed off on the North County program in 2003. Will the open-space areas and the corridors be sufficient to ensure the survival of all these different key species that are indicators of the healthy habitat? The data being collected by the survey teams should help to answer that, Martin asserts. "If we see a great drop-off in the variety of species and a die-off in 10 or 15 years from now, we can say it didn't work." But if the numbers haven't changed that much since the tracking surveys began in the mid-1990s, it may be possible to declare the open-space network a success.

East of Poway, the Iron Mountain recreational area and some land formerly owned by the Boys & Girls Clubs lie on the east side of Highway 67, while the 1800-acre Sycamore Canyon Open-Space Preserve runs up to the west side of the road. This land accommodates a lot of wild animals, and their natural flow is through the ravines crossed by the highway, according to Martin. On a busy weekday morning, it can be hard to imagine a human being braving the car and truck traffic, let alone a mule deer or an opossum.

So the trackers have been watching metal and concrete culverts that run under the highway. They've been searching for animal tracks on both ends of these tunnels, and within them; sometimes they spread gypsum throughout the culverts to help record the animal crossings. Martin says it appears as if only bobcats, coyotes, and some of the smaller species have been braving the passageways. "We haven't had any evidence of either lions or deer going through those. The deer are actually crossing at the grade, and there have been kills along the road -- of not just deer but coyotes and ringtail cats and other animals." Caltrans plans to widen the highway at some point, and the trackers hope to use their survey findings to help the road planners design more animal-friendly underpasses.

Besides working with the local tracking efforts, Martin says he'd love to help set up other tracking teams throughout the West Coast and the rest of the country. He also is working to establish an institute here that will offer an intensive nine-month tracking course. The goal is to produce graduates who can be hired by the Bureau of Land Management, the Department of Fish and Game, and other public and private agencies that are looking for individuals with tracking skills. Martin has targeted the fall of 2007 for the start of the first classes.

He's hoping to inspire the enrollees with experiences like the one he had one morning in the eastern end of Peñasquitos Preserve. He was following some fresh tracks belonging to a female deer and a fawn. He says the animals worked their way into a thicket, and after he had advanced as close as he could, he settled down to observe them. While he was lying there, he realized he was stretched across a trail bearing the tracks of wood rats. One of the creatures "came heading down the trail like it probably did every day for who knows how long. It was going about its business when it found itself face to face with this human lying across the trail. There we were, nose to nose." Martin says the animals' reaction reminded him of something he might see in a cartoon. "Its eyes got big, and it sat up on its haunches, and it looked at me. I expected it to turn tail and run the other way, but it just sort of sat there, tilting its head for, like, five minutes."

Martin says he's become convinced that "the biggest key to becoming a good tracker is an overall propensity to want to be quiet. To quiet yourself in such a way that you can really be aware. And when I say awareness, you've got the five senses, but they're just a doorway to a deeper awareness. It's so important to be able to stop and listen deeply, with your whole being."