As one drives east along Mexico’s Highway 2, climbing out of the desert up into the cooler Sky Island mountains of the Sonoran Highlands, they pass countless desert peaks draped with saguaro and organ pipe cactus. Before too long, Emory oak, Mexican blue oak, alligator juniper, cottonwood, sycamore, and even the humidity-loving epiphyte Tillandsia begin to appear. This is the land of the jaguar.
But the jaguar—and several other species that call the region home—faces an almost insurmountable threat: Mexico’s Highway 2 has taken thousands of lives, both human and animal. With wildlife crossings, we can reduce the risk of wildlife-vehicle collisions and potentially save lives, putting us one step closer to a reconnected and rewilded North America.
Making Mexico’s Highway 2 More Wildlife Friendly
In late March, Wildlands Network’s Mexico and Borderlands programs hosted a trail camera workshop at Rancho El Aribabi in northern Sonora, Mexico. With the Northern Jaguar Project, we trained biologists from Ecogrande AC (“AC” is the rough equivalent of a nonprofit in Mexico), based in Hermosillo, Sonora, on how to place and program trail cameras as part of the first step in assisting the Mexico Secretariat of Transportation with building wildlife crossing structures.
In the future, the biologists we helped train will use images captured from trail cameras to conduct an intensive study of the wildlife who depend on permeable roads as part of the Mexico Carretera Federal 2 (Highway 2) Road Ecology Project.
Shortly after convening at the Ranch, we wasted no time before hiking down the Rio Cocóspera to set our practice trail cams in hopes of capturing some overnight shots of elusive wildlife along the exceptional riparian corridor. Our hopes were high when we spotted a fresh deer kill; we knew something was lurking along the river. Perhaps the mystery would be revealed the next morning.
Practicing Road Ecology Along Mexico’s Highway 2
The concept of road ecology, or the study of the ecological impacts of roads and infrastructure, in Mexico was seeded in part by the efforts of Wildlands Network’s Mexico Program Director, Juan Carlos Bravo, who held the first Sonoran Road Ecology Conference in Hermosillo in October 2017, with funding from the U.S. Fish and Wildlife Service’s Wildlife Without Borders Program. A diverse cross-section of attendees at the standing-room-only conference included engineers, biologists, and government civil servants. It’s not hyperbole to say this event was instrumental in driving current efforts by the Mexican federal government to pass legislation requiring wildlife crossings on major highways.
Federal transportation authorities are currently widening Highway 2 into a 4-lane highway in the Sky Island mountains stretch between Ímuris and Janos, a project well-past due with a body count to prove it. The ever-increasing count includes not only humans, but also several species of wildlife. Results from research conducted by Sky Island Alliance, Cuenca los Ojos & Wildlands Network indicates that as many as 2,000 vertebrates, comprising 36 species, are killed each year in the Sky Islands stretch of Highway 2. In 2017, Ecogrande and Wildlands Network completed a project that surveyed every drainage between Ímuris and the Sonora/Chihuahua border that crosses Highway 2 in order to determine the most effective places to build wildlife crossings.
Securing the stretch of Highway 2 that passes through Aribabi is a high priority because it is a “pinch point” along one of 2 known corridors for jaguar dispersing north to the U.S. It’s impossible to know, but perhaps Macho B or El Jefe passed through here on their way north. From the high points on the ranch, one can see the Patagonia and the Santa Rita Mountains, which are known haunts for both jaguars and ocelots.
A Dangerous Road
Few highways in Mexico cut through more biotic communities than Mexico’s Highway 2. Starting near the cold waters of the Pacific Ocean at Tijuana, Baja California Norte, the treacherous 2-lane road runs across North America’s hottest and driest desert, El Gran Desierto de Altar (which contains the famous volcanic craters and lava fields of the Reserva de la Biosfera El Pinacate), up and over the northern Sierra Madre “Sky Island” mountains, and across the semi-desert grasslands of Chihuahua and Coahuila before ending its 2,000-mile journey in the Mexican state of Tamaulipas, where the Rio Grande empties into the warm waters of the Gulf of Mexico.
Although the road has spectacular scenery, its purpose is not to facilitate tourist travels throughout the breathtaking region. Highway 2 passes within a few kilometers of every port of entry on the U.S.-Mexico border, linking every border town in Mexico and providing an economic thoroughfare. However, despite the highway’s importance to the region’s infrastructure, it’s lined with more milagros (small, ceremonial chapels packed with prayer candles) and Virgen María de Guadalupe murals than one can count to honor the thousands of fallen truckers and travelers who have lost their lives along this treacherous highway.
In addition to the fallen truckers and travelers, Highway 2 threatens an exceptional number of charismatic species in Sonora. El Gran Desierto de Altar may seem like a vast, uninhabited and inhospitable wasteland to the uninformed, but it is home to one of the most threatened mammals in North America, the Sonoran Pronghorn. Despite being the fastest land animal on the continent, it is no match for a vehicle. Fencing has been installed in crucial places in Sonora along Highway 2, which has helped mitigate vehicle mortality.
Although small and barely noticeable when speeding along at 100km/hour, the sandy plains of Pinacate are also home to the eminently kissable flat-tailed horned lizard (Phrynosoma mcallii), or “cameleon” as it’s known in Mexico. The reptile is a species of special concern in both the U.S. and Mexico. Not only has it suffered from the usual human effects of habitat loss, but being an ectotherm, it’s also quite prone to being a victim of road kill, as it uses the black highway pavement for thermoregulation and digestion after a day of foraging for ants.
What’s more, the natural dispersal and rewilding of the black bear from the north faces the omnipresent danger of Highway 2. While it’s likely that black bear numbers in Sonora are increasing, thanks in part to the populations in Arizona and New Mexico that are inadvertently seeding the rewilding of black bears in the region, the highway is still a major obstacle to the species’ recovery. In June 2012, a vehicle struck and killed a black bear near Cananea, Sonora. Further north, in the U.S., a black bear was killed near Sierra Vista that same year, while another was killed crossing Interstate 10 east of Tucson, Arizona in 2017. A quick Google search illustrates the problem and shows that people suffer, too.
The Northern Jaguar Reserve (NJR) was established in 2003, right about the time trail camera technology became popular, so they possess what may arguably be the most experience in camera monitoring of jaguars of anyone in northern Mexico. Reserve Biologist Miguel Gómez Ramírez manages and maintains more than 100 trail cameras on a regular basis and has done so for almost a decade. Following an early morning PowerPoint presentation by Miguel, which included a history and evolution of trail cameras, and many spectacular photos of jaguars from the NJR, we set off to check the “traps” we’d set the night before.
Pulling the SD cards from the cameras felt a little bit like an Easter egg hunt, with everybody hoping they would find the “golden egg,” or in this case the furry golden egg with black spots—the jaguar. A successful trail camera involves not just good camera placement, but a lot of time and luck, though we were short on the former. As we quickly tabbed through the nearly 100 shots taken in less than a 24-hour period by the 6 cameras we had set, it was clear that the cameras had mostly captured blowing tree branches which triggered the camera’s motion sensors. However, when I checked the camera I had placed near the fresh deer kill, I was greeted with a delightful and comical series of photos of 2 Chihuahuan ravens hopping around and nibbling on the deer.
Making Highway 2 Safer for All
Road kill is a global problem for both people and wildlife. While roads allow us to travel safely back to our families and our homes, we risk the danger of being road kill ourselves if we hit a bear, deer, elk or moose while hurdling down highways at breakneck speeds. Even a slight swerve at high speed in order to avoid a flat-tailed horned lizard could be lethal. Highway overpasses and underpasses benefit us all by reducing such wildlife-vehicle collisions. It is imperative that we do as much as we possibly can in order to ensure that everyone, including wildlife, arrives home safely.
It is imperative that we do as much as we possibly can in order to ensure that everyone, including wildlife, arrives home safely.
The camera-trapping workshop we hosted represents another step forward by Wildlands Network to make Highway 2 a safer obstacle for wildlife and people. It’s just one action in a series of many small but significant actions that make effective wildlife corridors a reality. You can help by being mindful and observant when driving, and maintaining a close lookout for our furry, feathered and scaled friends. The burden of responsibility lies on us to make our highways safer for all.
With our assistance—and using the skills we taught them—the Ecogrande biologists will deploy as many cameras as possible over the next 2 years on the 700+ drainages that pass beneath the highway that Ecogrande identified in 2017 during phase 1 of the Highway 2 Road Ecology Project. But at a cost of about $200 per camera, we obviously can’t place a camera at each drainage. If you would like to help us add additional cameras to the Highway 2 project, please consider making a donation to the Mexico Program. We’ll send you the images we capture, and you can be part of the hunt, too!