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.