Impacts on Wildlife and HabitatThe short- and long-term effects of the border wall on wildlife and its habitat include:• Mortality caused by construction activity, enforcement

vehicles, stress and loss of habitat and access to resources• Blockage of the corridors that accommodate migrations

and other movement—including northward shifts in range as species adapt to climate change

• Obstruction of access to seasonally important resources

• Displacement of species and disruption of wildlife ranges

• Destruction, deterioration and fragmentation of habitat, including movement corridors and areas recently replanted or otherwise restored

WILDLIFE AND THE WALLBORDER BARRIER WILL HAVE SERIOUS IMPACTS ON SPECIES AND HABITAT

FACT SHEET

Within his first seven days in office, President Trump signed an executive order to build a wall along the 1,254 miles of the U.S.-Mexico border not already blocked. The wall’s construction, maintenance and enforcement operations will have significant consequences, not just for affected human communities, but also for a diversity of wildlife as well as vast expanses of pristine wild lands, including national forests, national parks, national wildlife refuges and wilderness areas. Border construction can be exempted from all federal, state or local laws by waivers under the 2005 REAL ID Act. Since the act was passed, the Department of Homeland Security has waived 37 laws.

• Prevention of the gene flow necessary to keep populations healthy

• Alteration of water flows and related hydrologic processes in streambeds and floodplains

Javelinas at an existing section of wall that disrupts their borderland habitat. Nearly 700 miles of the 1,953-mile U.S.-Mexico border is already blocked by walls, fences and other barricades, impeding the movement of wildlife in search of food and mates and cutting off migration routes.

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A border wall will cut off populations of endangered Mexican wolves, eliminating much needed opportunities to interbreed and increase the genetic diversity of the species essential to its recovery.

Wildlife and Wild Lands at RiskThe U.S.-Mexico border intersects several major habitat types and is regularly crossed by wildlife migrating north and south. According to the U.S. Fish and Wildlife Service, at least 89 endangered or threatened species and 108 species of migratory birds could be affected by activities in the border region. Four national wildlife refuge complexes could also be affected. These refuge lands each represent tens of millions of dollars of federal investments for acquisition, management and rehabilitation, as well as decades of binational collaboration to ensure wildlife habitat is connected and pristine.

The wall would seriously impede the recovery of two critically endangered species, jaguars and Mexican gray wolves. Any wall along the border of Mexico would have to pass through designated jaguar critical habitat, preventing the movement of jaguars between Mexico and the United States, which is vital to re-establishing a jaguar population in the United States. Populations of Mexican gray wolves would also be cut off. With just 113 of these wolves—the most endangered gray wolf species in the world—in U.S. borderlands and 35

in Mexico, the inbreeding that would result could jeopardize their continued recovery.

Other wildlife that could fare badly include ocelot, bighorn sheep, cactus ferruginous pygmy owl, desert tortoise, wild turkey, quail, Sonoran pronghorn, black

bear, mountain lion and coati. New barriers along the border would increase the number of species at risk, especially in three biologically rich regions: coastal California, the Gulf Coast of Texas and the Madrean Archipelago or “Sky Islands” of southeast Arizona.

References

U.S. Government Accountability Office. Border Security: Progress and Challenges in DHS’s Efforts to Implement and Assess Infrastructure and Technology. GAO-15-595T. 2015. http://www.gao.gov/assets/680/670176.pdf.

Neely, J. and K. Vacariu. Ecological Considerations for Border Security Operations Outcomes and Recommendations of the Border Ecological Symposium, Tucson, Arizona, March 9-10, 2005. http://www.defenders.org/sites/default/files/publications/march_2005_border_ecological_symposium.pdf.

Flesch et al. 2009. Potential Effects of the United States-Mexico Border Fence on Wildlife. Conservation Biology. Vol. 24 Issue 1.

Lasky et al. 2011. Conservation biogeography of the US-Mexico border: A transcontinental risk assessment of barriers to animal dispersal. Diversity and Distributions 1-15.

McCallum et al. 2014. Conservation on International Boundaries: The Impact of Security Barriers on Selected Terrestrial Mammals in Four Protected Areas in Arizona, USA. PLOS ONE Vol. 9 Issue 9.

DEFENDERS OF WILDLIFE

1130 17th Street, N.W. | Washington, D.C. 20036

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Walls and other barriers at the border fragment and destroy fragile habitat like the Sonoran Desert, home to the desert tortoise and other imperiled species.

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