In Search of Answers to Wildlife Survival Along L. A.'s Urban Fringe : Santa Monica Mountains: A study is exploring questions central to conservation efforts in the region, where rampant development is occurring.
Ray Sauvajot took the desert wood rat out of the metal box trap and grasped it by the scruff of the neck. With a green Magic Marker, he streaked the belly fur before releasing the creature into the brush.
During the last two months, Sauvajot has dyed enough chaparral rodents to start a punk fashion craze. But that is not why he and his colleagues have spent the summer on the hot, brushy slopes of the Santa Monica Mountains.
A research ecologist and doctoral candidate at UC Davis, Sauvajot, 25, is heading up a multi-year study exploring questions that are central to wildlife conservation efforts in the Santa Monicas, where rampant development is occurring alongside a network of protected mountain parks.
How does development on the urban fringe affect neighboring wildlife preserves? Does such urban encroachment reduce wildlife diversity? Could it lead to extinction of sensitive species, such as mountain lions?
The study by Sauvajot and his research collaborator, Marybeth Buechner, relies on an intensive program of trapping small mammals and observing birds in the mountains above Encino, Tarzana and Woodland Hills. These species are considered good indicators of environmental change and are prey for larger animals that are more difficult to study.
Although final results are not expected for at least a couple of years, one preliminary finding seems encouraging. Within peninsulas of habitat that jut into developed lands, wildlife diversity seems comparable to that in more isolated interior areas of the mountains. Sauvajot stressed that this is more an impression than a firm result.
But on a recent morning, as Sauvajot and his volunteer assistants, 21-year-old UC Davis undergraduates Sara Kelly and Andor Czigeledi, checked their traps, one amusing conclusion seemed well-established. Judging from their captive rodents and their rainbow coiffures, it appeared that hunger conquers fear.
Consider the desert wood rat with the wild green do, which urinated and squirmed to avoid being handled. The terrified creature had been through it all before. Prior markings established the fact that, for three straight days, the plump rodent had been unable to resist the siren song of peanuts and sunflower seeds.
“This is the third time we’ve caught this individual,” Czigeledi said. Being trapped “apparently . . . is not that stressful.”
The traps frequented by this wood rat lay along a steep, rocky trail southwest of Encino Reservoir. From Mulholland Drive, the path descended for more than half a mile through thickets of chamise and other shrubs, passing over a series of knolls.
The path came to a dead end on a bluff overlooking a scene that served as a counterpoint to the work at hand. A few hundred feet below, a hill had been stripped bare of vegetation to grade pads for luxury houses, leaving the site in the shape of a low-slung Mayan temple.
The study is to be Sauvajot’s doctoral dissertation and may appear someday in scientific journals, perhaps evoking images of white lab coats and climate-controlled surroundings. The reality--a punishing routine of grunt work--is far different.
Every day since July 1, without a break for weekends or holidays, Sauvajot and his colleagues have rolled out of their sleeping bags at nearby Malibu Creek State Park a little after sunrise for the start of a long day’s work. From there, they have driven to trail heads near the Mulholland crest for the first of two daily visits to their trap lines.
In the morning, they hike to two different trapping areas, checking a total of 100 traps. They release the animals captured after logging pertinent data, such as sex, physical measurements and whether the animals are recaptures.
On this particular morning, there were but two captures on this line of 50 traps. The second one, another wood rat, had also been captured before.
A lone female brush mouse, all whiskers and tail, was the only capture on a second trap line about a quarter-mile to the west. Usually, there are about five captures for each 50 traps, so the pickings were slim on this day.
The markers used to tag the animals have nontoxic ink that fades quickly, the researchers said. It was applied only to the animals’ undersides so they won’t be more conspicuous to predators.
During their morning rounds, the researchers also made a record of birds in the trapping areas, identifying them by bird calls and sight.
To assure that none of their captives died inside the metal trap during the heat of the day, the researchers closed all the traps after checking them in the morning. Then they headed back to camp to rest until late afternoon, when they returned to set the traps.
Throughout the summer, two lines of 50 traps were moved from one spot to another every five days. By the middle of last week, the group had finished monitoring its 15th and 16th trapping areas, bringing the current phase of the study to an end.
Sauvajot now heads back to UC Davis to regroup and look for financial support to continue his work. Despite the help of volunteers and parks agencies, he said he has barely scraped by.
He and his assistants have camped free this summer at Malibu Creek, courtesy of the state Department of Parks and Recreation, which also operates Topanga State Park, where some of the trapping has been done. And the National Park Service, which administers the Santa Monica Mountains National Recreation Area, lent Sauvajot the box traps and a four-wheel-drive vehicle to navigate the bone-jarring surface on the unpaved portion of Mulholland.
Sauvajot’s study could also help the park agencies, which face the daunting task of managing wildlife habitat in one of the nation’s most populous urban areas.
According to Sauvajot, a good deal of ecological research is carried out in pristine environments, rather than habitat on the urban fringe.
“My interest,” he said, “has been in doing research that can be directly applied to conservation problems that we’re facing now.”
One nice surprise this summer was a lack of close encounters with rattlesnakes.
However, Sauvajot once disturbed a nest of yellow jackets and paid for the mistake with about eight stings. “That was the quickest I ever ran up one of these trails.”