Continental Divide

Printer-friendly version

Borderlands, wildlife, people and the wall

by Krista Schlyer

© Jack Dykinga

© Jack Dykinga

Moisture from a morning rain hangs heavy in the air, clinging to spider webs, flower petals and the Spanish moss draped over the shady canopy of trees at Santa Ana National Wildlife Refuge. A tiny tree frog rests upon the wood railing along a trail, while plain chachalacas gobble and complain and green jays and malachite butterflies appear in bursts of tropical color through the deep green of the forest.

The landscape masquerades as Costa Rica, but in reality this refuge lies in Texas' Lower Rio Grande Valley, just north of the border with Mexico. Here, since the 1940s, the national wildlife refuge system has sheltered a rare treasure trove of life.

"The four most southern counties in Texas constitute one of the most biologically diverse regions in North America," says Nancy Brown, public outreach specialist at the South Texas Refuge Complex. "We have a documented 1,200 species of plants, 513 species of birds and nearly 300 butterfly species." Many of the creatures that dwell here exist nowhere else in the United States.

Like many of the borderlands ecosystems shared by the United States and Mexico, the Lower Rio Grande Valley is a bridge between north and south, and therefore a landscape of incredible richness—biologically, as well as culturally and historically. And, like much of the nearly 2,000-mile border between the United States and Mexico, the lower valley of the Rio Grande is being eroded and divided by roads, barriers and other infrastructure related to the construction of a border wall.

Legislation passed in 2005 gave the U.S. Department of Homeland Security unprecedented authority to waive laws to build the wall, and since that time the department has ignored the Endangered Species Act, Clean Water Act, Clean Air Act and dozens of other laws while constructing almost 600 miles of barrier. Not surprisingly, the wall is having major impacts on the wildlife of the borderlands. As earthmovers, concrete and steel supplant trees, pollute rivers, obstruct pathways for wildlife and destroy habitat, the border wall threatens to unravel borderlands ecosystems. Despite the recent change in presidential leadership, construction continues, focused mainly on the sensitive south Texas region, where only a fraction of the native ecosystem remains in a sea of farmland and housing developments.

"About 95 percent of habitat here has been cleared—it's gone, there's nothing left," says Brown. "So all of this diversity is supported by 5 percent remaining habitat."

In the late 1970s, the wildlife refuge system began piecing together what was left of the native ecosystems, making space for the tremendous wealth of native birdlife and creatures like the endangered ocelot and jaguarundi.

"We have 17 federally listed threatened or endangered species," Brown says of the lower four counties of south Texas. That's as many or more than some whole states.

To make the remnants of native land valuable for terrestrial wildlife, the refuge and its supporters worked to create corridors for creatures to travel from one small parcel of land to another. The refuge also began buying farmland and undertaking the arduous process of restoring the native flora.

On one parcel, the Monterrey Banco tract, staff had worked for more than a quarter-century replanting native shrubs and trees and restoring what had been bare land into an island of habitat. Just when the refuge had succeeded at the project, and threatened species like indigo snakes and Texas tortoises were starting to make their homes on Monterrey Banco, construction began on the border wall.

The wall here, as in much of south Texas, is being built into the levee system rather than along the Rio Grande. The Monterrey Banco tract sits between the Rio Grande and the levee, so in addition to tearing up restoration work to build roads and 18 feet of concrete wall, the refuge now sits south of the border wall. Many refuge tracts and private preserves—along with private property seized through federal action—will lie south of the border wall if construction continues as planned.

Farther west along the borderlands, trees become scarce and the landscape opens wide into expansive grasslands, home of kit fox, porcupine and pronghorn. At the border of New Mexico and the state of Chihuahua, Mexico, some of the continent's most intact grasslands endure. This ecosystem, now considered one of the most imperiled in the world, has been nearly erased from North America by agriculture and development. In the borderlands, due to the persistence of ranching, large remnants of grasslands remain, providing habitat for keystone species such as bison and prairie dogs, and offering hope to scientists that with some assistance, a rare native ecosystem could be mended here.

But construction of walls, roads and other barriers now imperils the ability of these animals to move on the landscape and thus reclaim their roles in the ecosystem. The international border, which was nearly imperceptible a few years ago, is now clearly cut by wide roads and steel barriers. If construction continues, it will block all north-south movement and access to crucial habitat for bison and pronghorn, and may also disrupt the movements of prairie dogs, deer and other species.

For Mexico this means that one of the country's most endangered wildlife species, pronghorn, will be in further peril. Border barriers now sever the Animas Valley, a critical grassland haven for the species in Mexico. If deprived of access to the entire valley's food and water sources, this pronghorn population may not be able to persist, according to Rurik List, a biologist who works at the National University in Mexico City.

Both Mexico and the United States have also been working to re-establish bighorn sheep populations. The sheep travel through mountain chains that span the border, and have been migrating from healthier populations north of the border to take advantage of land to the south.

"But with a wall, that's out of the question," List says.

The natural and essential process of animal migration, a key component of wildlife survival and evolution, now hangs in the political balance. Countless species—from the Mexican gray wolf and jaguar to the rattlesnake and beaver—will feel the impacts.

In the San Pedro River corridor, which crosses the border in southeastern Arizona, cottonwood trees tower over a shady riverbed imprinted with the feet of many wild creatures—including bobcat, mountain lion, turkey, coatimundi and small rodents. Outside the river corridor, open grasslands spread for many miles to the south, and climb the Huachuca Mountains to the west.

The land is managed by the Bureau of Land Management, which, in 1999, began reintroducing beaver, a keystone river species absent from the San Pedro for decades due to fur trapping and habitat loss and degradation. The reintroduction was such a success that during a flood a few years later, the beavers naturally made their way south of the border, to Mexico, where the species was not only gone from the river but considered endangered nationwide.

Unfortunately, in 2007, the Department of Homeland Security began building barriers in the river corridor. Defenders of Wildlife and its partners sued to stop construction, and won a temporary restraining order in federal district court. But the department invoked its waiver authority, and dismissed all the laws that the judge had cited in the case. Today steel barriers slice through the corridor right to the water's edge. People are often seen climbing the wall or cutting through, but the easiest passage for human traffic is now through the fragile river habitat, where some creatures find their only haven in southeastern Arizona.

The ability of walls to shift the paths that people take to the United States highlights the broad impacts of U.S. border policy on this region. Construction of walls in urban areas caused human traffic to shift to remote areas, bringing increased trash and illegal roadways to fragile southwestern landscapes. In response, the Border Patrol has built more roads, and engaged in off-road vehicular chases with smugglers, tearing up some of the continent's most pristine arid habitats.

Farther west, the high desert sinks in elevation and transitions into the Sonoran desert, home to the iconic and endemic saguaro cactus, endangered Sonoran pronghorn and threatened desert tortoise. To survive the harsh climate, animals here restrict activity to cooler times of day and arrange their movements around reliable watering holes. But in the past few years, this landscape—including national park and wildlife refuge land—has been severed by walls impenetrable to local wildlife, in many cases putting water and food resources just out of reach. As droughts in the Southwest become more common because of global warming, the wall's harm to desert wildlife will grow.

"The border wall in a climate-change environment is very dangerous because it won't allow the movement of species north as the climate gets hotter," says List. "If you put a wall that doesn't allow plants and animals to move north, it may become a wall of extinction."

But the clock has not yet run out on borderland species and habitat. Defenders of Wildlife and a coalition of conservation, business and human-rights groups are working both in the courts and Congress to halt the reckless expansion of the border wall, and advocating the adoption of other, less harmful methods for protecting our borders. (See sidebar for more information.)

 "Few areas in North America are as biologically diverse as the U.S.-Mexico borderlands," says List. "We have to be creative and find new solutions to restore the cross-border ecological processes that forged this unique region."

Krista Schlyer is a writer and photographer who helped organize the recent photo expedition by members of the International League of Conservation Photographers to the borderlands region.

Go Behind the Scenes on this story:

More Articles from Summer 2009

Global warming and other perils are pushing some of these birds to the brink
Help is on the way for right whales in crowded East Coast shipping lanes
Global warming legislation faces an incredibly tough battle before it can be enacted by this Congress, and overcoming Big Oil and other entrenched corporate interests is...
Please Bear With Them; The Eyespots Have It; Meat Your Mate; Dolphin Days are Here Again
Researchers believe that of the nearly 6,000 known amphibian species in the world, a third are in danger of being wiped out by the disease.
"Under the Bush administration, the Fish and Wildlife Service was willing to basically write the jaguar off because there are so few jaguars left in this country,"...
Wolves in Alaska are under the gun like never before.
"We're very disappointed that Secretary Salazar decided not to cut through the red tape and restore protections for polar bears immediately," says Defenders' executive vice president Jamie Rappaport Clark.
Wolf Woes Continue in the West; Tossing a Lifeline to the Fisher ; The Road Less Wanted; Defenders Carnivores Conference Set for Fall
Nearly as long as a bus and weighing almost 2.5 tons, no fish is more fearsome or famous than the great white shark.