Science Current Events | Science News |

Border fences pose threats to wildlife on US-Mexico border, study shows

July 13, 2011

AUSTIN, Texas-Current and proposed border fences pose significant threats to wildlife populations, with those animals living in border regions along the Texas Gulf and California coasts showing some of the greatest vulnerability, a new study from The University of Texas at Austin shows.

"Our study is the first comprehensive analysis of threats to species across the entire U.S.-Mexico border," says Jesse Lasky, a graduate student in the laboratory of Tim Keitt, associate professor of integrative biology. "The scale at which these fences stretch across the landscape is large, so it's important for us to also have a large- scale view of their effects across the continent."

Among the species at risk include four species listed as threatened globally or by both the U.S. and Mexico, and another 23 with small range sizes. The animals include the Arroyo toad, the California red-legged frog and the jaguarundi.

"We were able to identify a list of animal species that are most at risk and should be prioritized and monitored for change," says Lasky. "We're hoping this helps point decision-makers towards the animals to look at first when making priorities for conservation."

Most at risk of extinction are smaller populations of wildlife that occur in more specialized habitats, the study shows. Even animals that may appear to have large ranges may live in isolated habitats within those ranges that can be heavily disturbed by border fences. Human population growth along the border also poses threats to the wildlife.

Lasky says when the ranges of these animals are separated by barriers, including border fences and roads, the animals' ability to move is limited. The isolated populations are then more vulnerable to unforeseen disturbances, such as a hurricane or fire, which can wipe out an entire population. The isolation also increases inbreeding depression, which means the animals have limited opportunities to mix their genes with others and accumulate harmful mutations.

The study analyzed the ranges of 313 non-flying mammals, reptiles and amphibians and identified three major regions where wildlife is most vulnerable: the high human population areas of coastal California and coastal Texas and the unique "sky island" Madrean archipelago habitat in southeastern Arizona.

These regions have high numbers of vulnerable species. Some species in California have barriers that block as much as 75 percent of their ranges.

"The U.S.-Mexico border spans regions of extraordinary biological diversity as well as intense human impacts," says Keitt. "Loss of biological diversity can have negative impacts on the ecosystem services that are the basis of our life-support system."

The U.S. Department of Homeland Security is waived from environmental regulations when building security infrastructure. There are about 750 miles of border fences and human migration barriers along the border.


The study, by Lasky, Keitt and coauthor Walter Jetz, an associate professor in the Department of Ecology and Evolutionary Biology at Yale University, appeared May 3 online in the journal Diversity and Distributions.

University of Texas at Austin

More Border Fences Current Events and Border Fences News Articles

The Fence and the River: Culture and Politics at the U.S.-Mexico Border

The Fence and the River: Culture and Politics at the U.S.-Mexico Border
by Claire Fox (Author)

Book annotation not available for this title.
Title: The Fence and the River
Author: Fox, Claire F./ Claire, Fox
Publisher: Univ of Minnesota Pr
Publication Date: 1999/03/01
Number of Pages: 224
Binding Type: PAPERBACK
Library of Congress: 98050312

Border Insecurity: Why Big Money, Fences, and Drones Aren't Making Us Safer

Border Insecurity: Why Big Money, Fences, and Drones Aren't Making Us Safer
by Sylvia Longmire (Author)

When confronted with the challenges of border security and illegal immigration, government officials are fond of saying that our borders have never been as safe and secure as they are now. But ranchers in the borderlands of Arizona and Texas fear for their lands, their cattle, their homes, and sometimes their lives due to the human and drug smuggling traffic that regularly crosses their property. Who is right? What does a secure border actually look like? More importantly, is a secure border a realistic goal for the United States? Border Insecurity examines all the aspects of the challenge―and thriving industry―of trying to keep terrorists, drug smugglers, and illegal immigrants from entering the United States across our land borders. It looks at on-the-ground issues and...

Borders, Fences and Walls: State of Insecurity? (Border Regions)

Borders, Fences and Walls: State of Insecurity? (Border Regions)
by Elisabeth Vallet (Editor)

Twenty years after the fall of the Berlin Wall, the question remains 'Do good fences still make good neighbours'? Since the Great Wall of China, the Antonine Wall, built in Scotland to support Hadrian's Wall, the Roman 'Limes' or the Danevirk fence, the 'wall' has been a constant in the protection of defined entities claiming sovereignty, East and West. But is the wall more than an historical relict for the management of borders? In recent years, the wall has been given renewed vigour in North America, particularly along the U.S.-Mexico border, and in Israel-Palestine. But the success of these new walls in the development of friendly and orderly relations between nations (or indeed, within nations) remains unclear. What role does the wall play in the development of security and...

The Fence: National Security, Public Safety, and Illegal Immigration along the U.S.âMexico Border

The Fence: National Security, Public Safety, and Illegal Immigration along the U.S.–Mexico Border
by Robert Lee Maril (Author)

To the American public it’s a 2,000-mile-long project to keep illegal immigrants, narcotics, and terrorists on the other side of the U.S.–Mexico border. In the deserts of Arizona, it’s a “virtual fence” of high-tech electronic sensors, cameras, and radar. In some border stretches it’s a huge concrete-and-steel wall; in others it’s a series of solitary posts designed to stop drug runners; in still others it’s rusted barbed-wire cattle fences. For two-thirds of the international boundary it’s nonexistent. Just what is this entity known as “the fence”? And more important, is it working? Through first-person interviews with defense contractors, border residents, American military, Minutemen, county officials, Customs and Border Protection agents, environmental...

Far Beyond The Border Fence

Far Beyond The Border Fence
by George Alan Kelly

Far Beyond the Border Fence is a contemporary novel which brings the Mexican Border/Drug conflict into the 21st century. The owner of the VMR ranch, located in southern Arizona, on the Border, discovers that two of the ranche's prize quarter horses are missing and that his southern fence, leading into Mexico, has been cut. What follows will require a gallant effort, not only to retrieve his beloved horses and to rescue members of his family, but also to face an international plan to destroy twin American/Mexican cities.

The Third Nation: Life along the southern border fence

The Third Nation: Life along the southern border fence
by Mr. Richard P Rosenthal (Author)

A short history of how our southernmost border came into being. The "fence" now separating the nations of Mexico and the United States and how we might best resolve the issues this border presents to both nations.

Border Collies (Complete Pet Owner's Manual)

Border Collies (Complete Pet Owner's Manual)
by Michael DeVine (Author)

This energetic, intelligent working dog attained AKC recognition only in recent decades. Although an outdoors dog, it also makes a good family pet. This book is a brand-new title in Barron's extensive line of Complete Pet Owner's Manuals. They advise current and soon-to-be pet owners on the care of dogs and cats of virtually all recognized breeds, as well as on birds, reptiles, amphibians, fish, small mammals, and even exotic creatures like tarantulas and sugar gliders. The information in each book is authoritative but the language is non-technical and easy for every pet owner to understand. Every title in this series is individually written from first page to last by a breeder, trainer, veterinarian, or other animal specialist. All Complete Pet Owner's Manuals are filled with...

Border Games: Policing the U.S.-Mexico Divide (Cornell Studies in Political Economy)

Border Games: Policing the U.S.-Mexico Divide (Cornell Studies in Political Economy)
by Peter Andreas (Author)

The U.S.-Mexico border is the busiest in the world, the longest and most dramatic meeting point of a rich and poor country, and the site of intense confrontation between law enforcement and law evasion. Border control has changed in recent years from a low-maintenance and politically marginal activity to an intensive campaign focusing on drugs and migrant labor. Yet the unprecedented buildup of border policing has taken place in an era otherwise defined by the opening of the border, most notably through NAFTA. This contrast creates a borderless economy with a barricaded border.In the updated and expanded second edition of his essential book on policing the U.S.-Mexico border, Peter Andreas places the continued sharp escalation of border policing in the context of a transformed...

Fence Style: Surround Yourself With Charm & Elegance

Fence Style: Surround Yourself With Charm & Elegance
by James Harper (Author), Margie Roe (Author)

Good fences make good neighbors--and these beautiful styles will win the admiration of everyone in the neighborhood. Whether it's rustic, formal, or simply a charming old-fashioned white picket fence, it says volumes about the kind of living space you've established. Here's how to build one from scratch, choose a good ready-made version from a store, or decorate an existing fence so it's a landmark once again. A gallery introduces a range of types, from the kind found in a simple cottage garden to something fancy and elaborate. Use this as a springboard for selecting your own fence. Then get to work! The general information on construction covers tools, lumber, coatings, stains, paints, varnishes, and hardware, as well as specifics for building fences out of pickets, twigs, and lattices....

Out on Foot: Nightly Patrols and Ghostly Tales of a U.S. Border Patrol Agent

Out on Foot: Nightly Patrols and Ghostly Tales of a U.S. Border Patrol Agent
by Rocky Elmore (Author)

When Rocky Elmore joined the United States Border Patrol, he knew it would be a journey fraught with danger. But little did he know that the very real trails he walked night after night would soon lead him into surreal encounters from a different dimension. This was never more evident than when the ghost of a recently fallen fellow agent began to appear on top of the cliff from which he died. It marked the beginning of the end to one of the most bizarre series of events in the history of the U.S. Border Patrol. This collection of true stories provides a rare look into law enforcement that includes not only the routine nightly patrols of the USBP but also actual paranormal activity as it happened to the agents in the field. Readers will go on nightly patrols with the agents of the...

© 2015