The wall is solid mainly near major cities. Here, in the mountains, the government has opted for this lattice construction—called a Normandy barrier because it looks a bit like the obstacles that greeted Allied forces on D-Day beaches. It's intended to stop vehicles from driving across the border. That forces illegal migrants to enter on foot, theoretically making them easier to catch. But because an animal can go under or over the steel rails, it is also supposed to be more wildlife-friendly than a traditional wall.
McCain isn't so sure. He's tracked Macho B crossing the border at this very spot. "Just because it's possible for an animal to go through here doesn't necessarily mean they will," he tells me as he surveys the long line of steel. He thinks animals, including jaguars, might be too intimidated to cross. The Border Patrol is also expanding solid pedestrian fencing by 31 miles near Nogales, Naco and Douglas, Arizona, including a stretch that borders much of the Buenos Aires National Wildlife Refuge. It is also clearing 225 adjacent acres in order to patrol the fence line. In late August, the FWS issued an opinion that this fencing could act as a deterrent and "preclude jaguar movement into the U.S." Still, the FWS, acting on its belief that no breeding population exists in the United States, concluded that fencing would not affect the survival or recovery of the species. The fence construction continues.
Illegal traffic moving through the remote deserts of southern Arizona poses a conundrum for conservationists. Migrants disturb wildlife and pollute pristine areas with garbage and human waste. (In wooded areas or caves where illegal migrants hide out, knee-deep piles of refuse are sometimes left behind.) But fencing and the Border Patrol's trucks and ATVs pose equal—some say greater—risks to the fragile ecosystem. Most environmentalists say they would welcome a policy that would staunch the flow of migrants across the desert. With immigration reform going nowhere in Congress, however, such a solution does not seem likely any time soon. In the meantime, critics say the fences simply push immigrants into wilder areas. "We have not stopped a single person from coming into this country," says Neeley. "All we've done is move where they are crossing from urban areas into rural and remote areas."
Immigrants and drug traffickers use many of the same trails as jaguars. Each month, McCain discovers at least one of his cameras smashed. In response, he has taken to posting signs near the cameras in English and Spanish telling people that the photos are used only for wildlife studies. (He deletes those of people.) One volunteer for the Borderlands Jaguar Detection Project began putting small cards bearing the images of the Virgin of Guadeloupe and various saints by the cameras as a sign of goodwill in the hopes that migrants and drug runners will be less likely to damage them. McCain has also found that switching to infrared cameras—which use a flash not visible to humans—cuts down on camera vandalism.
One early May day, McCain and I hike down a rocky, brush-filled canyon several miles from Nogales, working our way toward the Mexican border past flowering yellow columbine and blooming white poppy thistle (and large clusters of poison ivy). McCain's dog Poncho races past, scaring some Montezuma quail into sudden, cooing flight. High up, a golden eagle searches lazily for its next meal. In the relatively wet canyon bottom, large oaks, sycamores and junipers have taken root. This is what biologists call a "riparian zone"—classic jaguar habitat. "If another jaguar is going to move into this country, it's going to happen right here," McCain says as he checks one of his cameras. But instead of sighting a jaguar, we hear shouting: a young Mexican man, scratched from head to toe from a fall through the brush and suffering a broken ankle, is screaming for help. We leave him some fresh water and promise to call the Border Patrol. (The man will be rescued by helicopter later that night.)
Encounters like these trouble McCain. He has documented both Macho A and Macho B in this canyon. But earlier this year, Macho B made a surprising move to a mountain range dozens of miles away. McCain wonders if the ongoing cat-and-mouse game between the Border Patrol, Mexican "coyotes" and drug traffickers has pushed the jaguar out.
Defenders of Wildlife has worked with other local conservation groups to create sophisticated maps of probable jaguar migration corridors. The groups hope to persuade the Border Patrol and the Department of Homeland Security to rely more heavily on so-called "virtual fences"—high-tech remote sensors and cameras that monitor the border without a physical barrier. But so far, they have had little success. "There is absolutely no table to sit at with the Department of Homeland Security that is meaningful in any way," Neeley says.
The Border Patrol maintains that its efforts ultimately save the environment. "If we are not patrolling that area, then there is going to be a lot more illegal traffic coming through," says Shannon Stevens, public information officer for the Border Patrol's Tucson Sector. "Illegal traffic leaves much more footprint than a Border Patrol agent would." She emphasizes that the Tucson Sector has to contend with a tidal wave of illegal migrants—it had already apprehended 295,700 of them this year as of September.
While checking McCain's cameras in the border canyons, we frequently catch sight of colorful plastic ribbons fluttering in the breeze: pink, blue, orange and yellow streamers attached to wooden stakes in the ground. "A lot of these are new since the last time I was here," McCain says. These are claim stakes, and they signal another looming threat for the jaguar: a mining boom.
A recent surge in mineral prices, driven by demand from China and India, coupled with technological advances, has made it economically viable for miners to return to the Arizona mountains they largely abandoned after World War II. Prospectors have rushed to restake old claims throughout the state, including in areas where jaguars have recently been documented. The miners are aided by an 1872 mining law that makes it extremely cheap to stake a claim on public land and gives priority to mining over almost any other activity. Mining companies doing exploratory work have already built new roads into forested mountainsides.