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The Border Wall’s Cascading Impacts on Wildlife

Update: On January 20, 2021 President Biden signed an executive order halting border wall construction. Wildlands Network continues to document the impacts of the border wall on wildlife in the region, using this data to inform recommendations on how to mitigate and reverse the wall’s effects.

2020 has been a difficult year for the planet in many ways. Our wildlands and wildlife have not been immune from this either, and this is especially so in the United States and Mexico Borderlands. In 2018 the Trump administration began building border walls across New Mexico, Arizona, and California. These walls, euphemistically referred to as “replacement fencing,” are 30 feet high and made of six-inch diameter steel beams (known as bollards) with barely four-inch wide gaps between the bollards, inhibit all wildlife movement for any creature larger than a cottontail rabbit.

More than 400 miles of border wall have been built over the last two years. Currently, mountains, Wilderness Areas, National Parks and Monuments, Areas of Critical Environmental Concern and National Wildlife Refuges, are all being blasted by dynamite and bulldozed to build the border wall. This is entirely unwarranted, unnecessary and is extremely destructive. Lands that have been set aside and preserved by Congress for future generations to treasure and enjoy are being detonated. This, at a time when illegal immigration along the border has been at its lowest level in decades. The border wall has been a political stunt, using $18 billion of American taxpayer dollars with the aim of obtaining re-election for Trump.

Although the genesis of the border wall was entirely political, its effects upon the land, wildlife, groundwater, biodiversity and connectivity are not political. The effects are real and measurable, with its ramifications cascading generations into the future, potentially altering the evolutionary history of North America.

The borderlands are not a desert wasteland like many people may perceive. The Sky Islands region of Arizona, New Mexico, Sonora and Chihuahua harbor some of the highest levels of biodiversity on the North American continent. But it’s not just numbers of species that are so crucial to the biological treasure that this region holds. The geographical prominence that the borderlands possess is unparalleled, for it is the crossroads of the Sierra Madre Occidental and the Rocky Mountains, where the Central American neotropics and the North American temperate zones converge. Nowhere else on Earth do the jaguar and the American black bear cross paths, and the Mexican gray wolf preys upon whitetail deer and peccary, the tropical pig-like species that ranges from Arizona to the Amazonian basin of South America. The construction of an impermeable border wall across the heartland of North America is an unconscionable act of destruction on a continental scale.

In late 2019, after border wall construction had begun in earnest in the San Bernardino Valley of southeastern Arizona, Wildlands Network, with generous material support of trail cameras from the Phoenix Zoo, began a wildlife monitoring program at the San Bernardino National Wildlife Refuge to measure the effect of the border wall on wildlife movement between the United States and Mexico. We partnered with Cuenca Los Ojos (CLO), a nonprofit conservation organization founded by Valer Clark, which shares the border with the Refuge on the Sonora, Mexico side. Dozens of trail cameras were installed in crucial locations where wildlife corridors were known to occur. The refuge and its sister CLO property, Rancho San Bernardino, contain the only reliable perennial water sources in a vast area of desert scrub. To make matters worse, 2020 was the driest and hottest year on record in Arizona. Less than two inches of rain fell. In a time when wildlife need more space and more access to resources, their options are being bisected by the border wall.

As of the second week of December 2020, all connectivity and movement between the United States and Mexico in southeastern Arizona has been stopped dead in its tracks. But the situation became even worse four months ago when the Department of Homeland Security, Army Corps of Engineers, and their contractors, Southwest Valley Constructors (Kiewit Corp.) began blowing up the Peloncillo mountains just east of the San Bernardino National Wildlife Refuge in Guadalupe Canyon. Guadalupe Canyon, managed by the Bureau of Land Management, has numerous levels of protection, including: Guadalupe Canyon Area of Critical Environmental Concern, Wilderness Study Area, and Outstanding Natural Area. It is also Designated Critical Habitat for the endangered jaguar. Flip through the Peterson Field Guides for birds and reptiles and you’ll find numerous notations by Roger Tory Peterson and Robert Stebbins stating “In the U.S., only found in Guadalupe Canyon.’ ‘A rare, but frequent visitor, in Guadalupe Canyon.” For 50 years, birders from around the country and the world flock to see the buff-colored nightjar, and herpetologists clamor to find the green rat snake. This biological jewel, a treasure of the natural world, also provides a vital link between the Sierra Madre and the Rocky Mountains, because the Peloncillo Mountains are the only mountains that connect the two great mountain ranges. This is ground zero for biological connectivity in western North America.

Further to the east, 100 miles of the border in New Mexico has been sealed off. This brings to a close the natural dispersal events that have been occurring for the Mexican gray wolf. The decades-long binational recovery program for the wolf, and hopes for the Mexico and U.S. populations to merge, has been effectively shut down. Mexican gray wolf recovery is not just a hopeful pipe dream, for in 2017 a male wolf from the mountains of Chihuahua, Mexico made a 600-mile journey, headed north, crossing the border near Las Cruces, New Mexico. The wolf spent a few days in town, made its way down the Rio Grande to Sunland Park, and returned to Chihuahua through a gap in the border wall in at Mount Cristo El Rey. Satellite GPS collar transmissions allowed us to track this journey. Sadly, in 2019 this gap was closed when a private border wall was constructed on the mountain over the objections of the local residents. Over the last two years two more wolves have crossed from Mexico into the U.S. But since then, a border wall now exists with gaps barely wide enough to fit a wolf’s tail.

The construction of border walls must stop immediately, and in places where they have inflicted extreme environmental impact, they must come down. More than 50 laws dating back to 1890 were waived by the Department of Homeland Security and the Trump Administration to build these walls. Due to the passage of the Real ID Act of 2005, they do not have to comply with NEPA, the Endangered Species Act, Clean Water Act, Clean Air Act, Antiquities Act, Native American Graves Protection Act, Bald Eagle and Golden Eagle Protection Act, etc. Politics are rapidly eroding our natural world and threaten the survival of many species.

Look beyond the political rhetoric and use sound data and judgment to decide for yourself what you would like to see for the future of the wildlands of North America. No single action has done more to destroy connectivity and functioning wildlife corridors in the Southwestern U.S.-Mexico borderlands as have the border walls constructed during last two years.

The list of species impacted is long: Sonoran pronghorn, peninsular bighorn sheep, jaguar, American black bear, ocelot, Mexican gray wolf and the Rio Yaqui fishes of the San Bernardino National Wildlife Refuge, whose water has been pumped from an Ice Age aquifer to make concrete for a Stone Age border wall. Yet it is not just the rare and endangered, and the charismatic fauna who are affected. It is the everyday common residents of these lands who are bearing the brunt and daily impact of the fragmentation of their home ranges and separation from their cohorts. In the absence of Environmental Impact Statements and the NEPA process, the effects upon wild ecosystems and wildlife will remain to be seen. What will happen when prey species like Coues whitetail deer, skunk, rabbits and javelina are cut off from the predators? Already, our observations at San Bernardino National Wildlife Refuge are grim. Trail camera detections of most species have declined, and movements of predators like mountain lions are now biased towards north to south moving pathways. What does this mean? These data suggest that there are mountain lions on the U.S. side who, until recently, had the freedom to cross the arbitrary international boundary and roam free and pursue prey in the territory in which they were born. Now they encounter a border wall as they walk south, turn left or right and pace the wall for who knows how long, then in the futility, head back north and then repeat the cycle again a few days later. This is what our trail cameras are telling us.

This absurdly tragic and destructive border wall would seem like an obvious and concerted object of research concentration and interest. Yet sadly, it has been extremely difficult to obtain funding for this crucial wildlife monitoring and research because of the so-called “political” reasons, despite the fact that the wall is inflicting irreparable damage upon the flora and fauna of our protected lands.

We need to continue monitoring and collecting data for another 18 months. Maintaining a binational wildlife monitoring project is not an easy task. Especially in the time of COVID. Many hands make light work, so we ask that many of you make as many small contributions as you can in order to allow this project, that has immense practical and management implications, to continue.

Myles Traphagen is Wildlands Network’s Borderlands Program Coordinator. He is based in Tucson, Arizona and has worked on the U.S.- Mexico border for 20 years.

2 thoughts on “The Border Wall’s Cascading Impacts on Wildlife

  1. I am saddened by my own lack of knowledge and ignorance to the issues this wall creates. Grateful for the information shared on this site. Prior I felt strongly that we needed to address “illegal” aliens since as the name states they are in the U.S. illegally and as such should not be. Looking at it narrow minded, the wall seemed like a solution. My eyes have been opened to the greater damage being done to our world. Thank you for opening my eyes and mind to the bigger picture.

  2. Humans need wildlife to exist. Without whales, birds, bees, bats, wolves, we all stop! I think it is time to give back to wildlife what we ignorantly took away. Every species has the right to live not just us. We need trees, clean water, clean air and without the interference from industry we will provide for all of us. We need to stop the chemicals. Insects get eaten by birds, bats, and others thus using chemicals and/or items like Round Up is killing all life and will eventually kill the earth. Tell me, how stupid is that? How selfish is that? How evil is that? Killing all living things? Seems as if mental assistance is required for that type of thinker, company, government, on individual. People need to step back and consider their actions on others. Everyone of us needs to do this, industry needs to do this, CEO’s need to do this. As is said with Covid, we are I this together. As with climate destruction we are, once again, all in this together. Be warned, make no mistake ,every individual person is responsible for our enhancement or our destruction. We collectively must make the choice of Life For All!!!!!

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