Large wild animals need space to roam, to find food and mates. Highways limit this space and can result in the slow “strangulation” of certain species, without mentioning the thousands of animals of all sizes that are killed simply trying to cross the road.
Actually, it’s far more than thousands. According to Scientific American, U.S. vehicles hit an estimated one to two million animals every year, the equivalent of a collision every 26 seconds. As a result, animal lovers around the world are urging their governments to incorporate wildlife passages into their highway systems.
Here in Jalisco, the first mention, some years ago, of an expressway bypassing Guadalajara caused consternation among many environmentalists. They had worked hard to create a wildlife corridor between Bosque la Primavera and the Bosque de Quila. The Guadalajara rock group Maná had purchased land in the Sierra de Ahuisculco between these two forests and turned it into an animal sanctuary now popularly known as Selva Negra. In theory, an 80-kilometer corridor had been created for animals such as white-tailed deer, coatis, lynxes, peccaries, jaguarundis, armadillos, foxes, ringtails and, of course, pumas — whose presence in these forests had only been discovered a few years ago with the help of camera traps.
The first fly in the ointment was the construction of the Circuito Metropolitano Sur, a four-lane highway running from Tala to Cajititlán. Fortunately, environmentalists convinced the road-builders to incorporate a lot of wide underground passages for animals. Then plans appeared for the Macrolibramiento, an even bigger highway essentially paralleling the first one and effectively rendering the biological corridor useless.
A hue and cry was raised and the Secretariat of Communications and Transportation (SCT) promised not only to build tunnels for animals, but to construct Mexico’s first animal overpass, strategically located to bridge the Primavera Forest and Selva Negra.
When this Animal Bridge was first announced, it was accompanied by a glamorous photo showing a carpet of green crossing an expressway. Wow, I said to myself, if there had been an animal overpass in the Garden of Eden, It would surely have looked like this. I’ve got to see it for myself. And I decided I would visit the beautiful animal bridge in person 
just as soon as the Macrolibramiento was up and running.
The fancy new toll road was inaugurated on January 8 of this year, so, a few days ago, I talked my friend Rodrigo Orozco into taking me out to see the Puente de Animales with my own eyes.
We headed for Ahuisculco and then drove east four kilometers. Suddenly we could see the silver ribbon of the Macro on the horizon and — oh no — binoculars were not necessary to reveal that instead of something out of the Garden of Eden, this overpass looked more like the Rocky Bridge to Gehenna.
“There’s not a blade of grass on it,” I exclaimed.
“Grass?” replied Rodrigo, “There’s no soil at all.”
We drove closer and walked to the overpass, which we found utterly barren, covered with a thin layer of scoria, which is sterile volcanic rubble. On top of that, it was sealed off with barbed wire. On both sides of the highway, high fences should have been constructed to keep animals from wandering onto the road and to gradually guide them toward the safe overpass.
Alas, this is not what we found.
“I think you and I, so far, are the only animals to have crossed this bridge,” I remarked to Rodrigo.
What was going on?
After posting photos of what we had seen on social media, Paco Quintero of the Selva Negra Foundation commented that complications had arisen among the SCT, the Community of Tala, and a local landowner.
“We’re trying very hard to resolve these problems,” Quintero told me. “We haven’t forgotten about the animal bridge.”
Meanwhile, the losers are the animals. Statistics show that highway crossing structures for animals reduce collisions with these creatures by upward of 70 percent.
Parks Canada says that animal bridges do work. They verified that hundreds of individually marked hoofed mammals have made “tens of thousands of crossings of such structures.” In the U.S. state of Montana, wildlife cameras recorded 22,648 successful animal crossings per year. Montana researchers affirmed that 14 years of on-the-ground monitoring and research before, during, and after construction of wildlife crossing structures demonstrated that animal crossing measures along Highway 93 North “have reduced wildlife-vehicle collisions and maintained or improved habitat connectivity for deer and black bear.”
The “Rocky Bridge to Gehenna” is not an auspicious beginning for Mexico’s first animal overpass. Let’s hope that the problems will soon be resolved, and that my next picture of that bridge will indeed look like it was taken in the Garden of Eden.