For Immediate Release

Today BioScience, a peer-reviewed scientific journal, published an article titled “Nature Divided, Scientists United: U.S.-Mexico Border Wall Threatens Biodiversity and Binational Conservation” that highlights the consequences additional wall construction will have on wildlife and ecosystems of the borderlands region. At the time of publication, 2,556 scientists from 43 countries had endorsed the article, and the number continues to grow. Scientists are invited to join as signatories here.

“Nature Divided, Scientists United” outlines three major ways border wall infrastructure and security measures threaten biodiversity by waiving environmental laws, eliminating and fragmenting animal and plant populations and habitat, and devaluing binational conservation investments and scientific research. Lead author Dr. Rob Peters and his colleagues identified five Borderlands Conservation Hotspots, representing top-priority areas of high biological diversity and binational investment in conservation directly threatened by border wall construction. The Borderlands Conservation Hotspots are described in detail in the 2018 report ‘In the Shadow of the Wall’ by Defenders of Wildlife.

The scientists’ message is being published in the same week the U.S. House of Representatives Appropriations Committee meets to advance its appropriations bill for the Department of Homeland Security. The proposed spending bill for FY 2019 includes $5 billion in funding for 200 miles of new border wall construction and associated technology. The House bill allows for construction anywhere along the border, including Santa Ana National Wildlife Refuge, a crucial wildlife habitat corridor.

In the BioScience article, scientists directly ask Congress and the Department of Homeland Security, in relation to construction of the border wall and national security operations, to:

  • Adhere to all U.S. environmental laws, including the Endangered Species Act and National Environmental Protection Act;
  • Undergo rigorous pre-planning and pre-implementation surveys to identify species, habitats and ecological resources at risk of impact;
  • Mitigate any environmental harm, especially in places with high ecological sensitivity; and
  • Facilitate scientific research in the borderlands, to complement and assist environmental evaluation and mitigation efforts.

Dr. Rob Peters, lead author of the article and Senior Representative in the Southwest Program for Defenders of Wildlife, issued this statement:

“No matter whether a wall or a fence, barriers at the border are impeding wildlife movement. What matters is whether the barrier is passable, and from a jaguar’s point of view, the border fence is just as unpassable as a wall.”

Dr. Jennie Miller, senior author of the article and Senior Scientist for Defenders of Wildlife, issued this statement:

“The scientists have spoken: a wall will irreparably change ecosystems in some of North America’s most biodiverse regions. If border walls and barriers are completed, wildlife like the Mexican gray wolf, jaguar, ocelot, and the Endangered Species Act-candidate ferruginous pygmy-owl could have their populations bisected. Scientists stand united, and we implore the Department of Homeland Security and Congress to conserve the ecological, economic, political, and cultural value of the U.S.-Mexico borderlands."

Jamie Rappaport Clark, CEO and President for Defenders of Wildlife, issued this statement:

“An overwhelming number of scientists have spoken – building additional border wall will threaten biodiversity and undermine decades of binational work to protect the region and wildlife along the U.S.-Mexico border. Nearly 700 miles of walls and other barriers have already been constructed on the border. Additional border wall would further bisect border communities and destroy wildlife habitat. The damage from additional border wall construction will be permanent and irreversible. Building more walls will only bring more devastation.”

Dr. Rodolfo Dirzo, Professor in the Department of Biology at Stanford University, issued this statement:

“It is precisely at these challenging times of social and political turmoil, driven by selfishness and lack of solidarity among countries (and sectors of society within countries), when unity among all members of society around the critical issues of maintaining the planet’s life support systems matters the most. The plan to erect a wall to divide the unique biological and cultural continuity existing in the Mexico-USA borderlands goes precisely in the opposite direction—and sets a terrible example. We urgently need voices of unity and solidarity that, by informing society (including politicians), help to prevent the negative impacts of one of the currently most pervasive drivers of biological and cultural diversity loss—fragmentation of habitats and societies. I only hope the voice of science expressed in “Nature Divided, Scientists United” will be listened by the relevant decision makers of the USA.”

Dr. Rurik List, Professor at the Área de Investigación en Biología de la Conservación in the Universidad Autónoma Metropolitana, issued these statements:

“Since the end of the last glacial period ten thousand years ago, animals have moved unhindered back and forth across the landscape of North America, from Canada to Mexico, shaping the ecosystems we know today. If the wall is completed, this barrier will become the mightiest one yet to divide the continent from coast to coast, completely halting the necessary animal flow of non-flying vertebrates to maintain the populations of many species in a vast region of North America.”

“A century of conservation efforts has brought back from the brink of extinction one of America’s most notable symbols, the plains bison. The wall will stop the movement of one of the few free-ranging bison herds in North America, and the one that moves between the grasslands of Chihuahua and New Mexico.”

Gerardo Ceballos, Professor, Instituto de Ecologia, Universidad Nacional Autonoma de Mexico, issued this statement:

“The U.S.-Mexico border is a region with amazing landscapes and impressive biological diversity, including a mixture of temperate and tropical species. If the border wall that already exists is completed along the whole U.S.-Mexico border, it will be the only human made barrier that divides a whole continent! Inflicting the massive damage that the wall will cause on the species that live in the border region is clearly both biologically and morally wrong.”

Defenders of Wildlife is dedicated to the protection of all native animals and plants in their natural communities. With over 1.8 million members and activists, Defenders of Wildlife is a leading advocate for innovative solutions to safeguard our wildlife heritage for generations to come. For more information, visit and follow us on Twitter @Defenders.

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