Wildlife Segregated by US Border Policy

The remote borderlands between the United States and Mexico contain vast and beautiful wilderness and include the richest diversity of plant and animal species in North America. Why then, did the US government, under the Bush Administration, choose to waive the many landmark laws set in place to protect these unique areas?

In the 1990s, in an effort to fight the increasing flow of illegal immigrants from Mexico, the US Border Patrol began erecting barriers in urban areas along the US-Mexico border starting with major cities like San Diego and El Paso. The Border Patrol installed two types of barriers: pedestrian fencing, the most restrictive, and vehicle barriers which impede the passage of vehicles but allow animals to cross. The many miles of barriers pushed migrants into remote and sensitive wilderness areas and wildlife refuges. In response to the shift, the US Border Patrol extended the wall into these previously undisturbed areas, endangering people, the ecological integrity of these pristine wild lands and vulnerable wildlife. High voltage lighting, low flying helicopters and the construction of roads have also disturbed wildlife.

US Border Policy
US Border Policy dramatically changed in 2005 with the passage of the REAL ID Act. Section 102 of this legislation gives the Department of Homeland Security the unprecedented power to waive in their entirety all local, state and federal laws that might interfere with the construction of infrastructure along the borders, including landmark laws enacted to protect the environment, historical sites and public health and safety. In 2006, yet another damaging bill was passed, the Secure Fence Act, which requires the construction of double steel, 15-foot high walls along approximately one third of the US border with Mexico, fencing in large portions of the Arizona, California and Texas borders.

In implementing the REAL ID Act, former Secretary of Homeland Security Michael Chertoff disregarded three dozen laws including the National Environmental Policy Act, the Endangered Species Act, the Migratory Bird Treaty Act, the Clean Water Act, the Clean Air Act, the Coastal Zone Management Act and the National Historic Preservation Act. Although the decisions to waive these laws were challenged by many groups, the REAL ID Act also stipulates that the Secretary’s decisions are not subject to judicial review and the legal challenges were therefore dismissed.

To date, of the nearly 700 miles of required fencing, 640 miles have been constructed along the US-Mexico border. The organization Taxpayers for Common Sense estimates that one mile of border wall costs taxpayers an average of $4.5 million, and an average mile of vehicle barrier costs $1.6 million. According to the Migration Policy Institute, increased fencing since 1994 has had no overall effect on immigrants’ ability to successfully cross the border and about 97 percent of undocumented aliens are eventually able to enter the US The barriers not only cut through federal and private land but split an entire continent in two. Fencing has been completed in all four southern border states and traverses a variety of distinct ecosystems, from mountain to desert, obstructing and degrading vital wildlife corridors. Access roads are just as damaging, having been carved through designated wilderness areas and wildlife refuges. The lack of guidance from environmental laws, public input or scientific analysis has led to floods, wildlife habitat fragmentation and the degradation of once pristine wilderness areas.

Affected Areas and Species
The isolation of the border region, high concentration of public lands and sparse human population make it a haven for plants and wildlife. Dozens of unique and endangered species inhabit the region, including jaguar, Sonoron pronghorn antelope, bighorn sheep, ocelot, jaguarundi and the Mexican gray wolf, which was recently reintroduced into the southwestern United States. The barriers have fragmented some of the most productive and irreplaceable ecosystems in the US, prohibiting wildlife from reaching vital resources such as water and mates. This restricted gene flow could have devastating long-term effects on wildlife populations, particularly those imperiled populations with already limited genetic diversity that depend on uninhibited movement between the US and Mexico. Wildlife in the region rely on open corridors and do not recognize human generated boundaries.

The impact of the barriers on jaguars in particular has drawn much attention. For many years jaguars were thought to be extinct in the US until sightings in Arizona in 1996. The last known wild jaguar in the US died in 2009. The barriers make the re-establishment of a healthy breeding population in the US nearly impossible.

Conservation photographer Krista Schlyer began documenting the impact of the wall on borderlands wildlife three years ago, “Back then I witnessed bison jumping the barbed wire fence that used to form the border of New Mexico and Chihuahua, Mexico. And I photographed two years later the new border barrier that will block passage not only of bison, but most large mammals,” she said.

In 2009, Schlyer, along with a group of photographers from the International League of Conservation Photographers, traveled the entire length of the border to document the impressive biodiversity of the region and raise awareness of the impact the border wall is having on the landscape and wildlife. Schlyer described the devastation she witnessed first-hand. “This is a very drought-prone area, and I have seen places where rare year-round water sources are now inaccessible to wildlife on the wrong side of the border wall. I have also personally seen wildlife attempting to cross the international border, and following the wall for 100 yards, only to turn away when there was no way to cross. There has been documentation of Sonoran desert toads jumping against the wall until they literally die of dehydration.”

Few studies have been conducted to measure the effects of border walls on wildlife populations, however, one such study was featured in the journal “Conservation Biology” last year. Using telemetry, researchers measured the potential effects of the border fence on desert bighorn sheep and Ferrginous Pygmy-Owls. Models of gene flow suggested that the nine populations of bighorn sheep in northwestern Sonora, in Mexico, are linked with those in Arizona. Obstructing the dispersal of the animals would isolate some populations and stop gene flow, limiting genetic diversity among all of the populations. Since bighorn sheep population sizes are already small, fencing could also cause population extinctions.

Similarly, researchers found that fencing would obstruct the transboundary movement of Pygmy-Owls, whose flight height averages only 4.5 feet above ground. Since Pygmy-Owls are endangered in Arizona yet more common in Sonora, the health of the US population is dependent on movement across the border. “The border wall presents a regional-scale barrier to the movement of wildlife, many of which—like the pygmy owl and desert bighorn—are already threatened with extinction,” said Matt Clark, a co-author of the study and Southwest Representative with Defenders of Wildlife. “Wildlife do not recognize political boundaries. To survive they need unhindered access to resources on both sides of the border, and also to exchange genetics between populations. Interruption of gene flow with an impermeable wall could threaten populations on both sides of the border.”

Black-tailed prairie dogs represent another vulnerable species that is reliant on migration. Although this species was once prevalent in the US, due to massive extermination efforts in Arizona and New Mexico the largest remaining colony in North America is now found in Mexico. Because of cross-border breeding, colonies have started to establish themselves in New Mexico, however, barriers could stop the further recovery of this species in the US Prairie dogs are considered a keystone species and play a very important role in their environment since they serve as prey for a number of predator species.

Peccary also play an important role in the ecosystem. The pig-like animal commonly consumes seeds and therefore serves an important role dispersing seeds throughout their environment. Blocking their movement will also inhibit the dispersal of many native plant species.

Along with the direct threat from the barriers themselves and the associated construction and infrastructure, the use of electric lighting also poses a huge threat to wildlife. The use of floodlights may negatively affect the movement of nocturnal animals such as some bird species and bats.

The following wilderness areas have already been compromised by construction along the border:

  • The San Pedro Riparian National Conservation Area (AZ) - The San Pedro River extends from Mexico into the U.S. and is renowned as one of the last free-flowing rivers in the Southwest. It is also designated as a World Heritage Natural Area and a Globally Important Bird Area;
  • Tijuana River National Estuarine Research Reserve (CA) - The last remaining big saltwater marsh in the region. It serves as a rare and vital patch of coastal habitat for migratory birds and endangered species;
  • The Otay Mountain Wilderness Area (CA) - It is home to the rare Tecate cypress tree which is the host plant for the even rarer Thorne’s hairstreak butterfly, found nowhere else in the U.S.;
  • The Lower Rio Grande Valley National Wildlife Refuge (TX) - It was created as an important wildlife corridor for endangered ocelots and jaguarondi.

Attempts are being made by Congress to restore laws to the borderlands in order to protect the environment and human health and safety, and fix the damage that has already been done. In May 2009, Representative Raúl Grijalva (D-AZ) introduced the “Border Security and Responsibility Act” (HR 2076) which calls for the analysis, monitoring and evaluation of the current border protection strategy, the return of laws to the borderlands and the analysis and mitigation of the environmental impacts of the barrier. In December of 2009, Representative Luis Gutierrez (D-IL) introduced “The Comprehensive Immigration Reform for America’s Security and Prosperity Act” (CIR ASAP). The bill contains critical components of Rep. Grijalva’s bill and is intended to ensure that the Department of Homeland Security obeys all applicable laws when building infrastructure on the border. “CIR ASAP would restore healthy ecosystems throughout our border wildlands, protecting precious species like the jaguar from the ravages of the border wall,” said Dan Millis, Sierra Club Borderlands campaign organizer. “If we want our borderlands to survive for future generations, then the border tenants of CIR ASAP must be included in the final version of any immigration bill passed by Congress.”

President Obama announced in March his dedication to passing an immigration reform bill this year. To prevent further degradation, it is imperative that any immigration bill that passes repeals section 102 of the REAL ID Act, restores the precious ecosystems throughout the borderlands and replaces the current strategy with one based on comprehensive analyses and consultation.

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