January 24, 2013
by Bob Ortega
PHOENIX -- The land where the antelope play, where Arizona meets Mexico, has been divided in recent years by taller and longer border fences.
They are meant to keep out or slow undocumented migrants and drug smugglers coming north from Mexico, but environmentalists say they're also helping drive two southeastern Arizona pronghorn antelope herds to the brink of dying out.
Environmentalists say the inability of the pronghorn — and other wildlife — to range freely across southern Arizona and northern Mexico has contributed to dramatic declines in the population of what are known as the San Rafael and Sonoita herds. From 122 animals identified in a 2005 count, the herds' numbers fell to 26 in a survey last year, according to the Arizona Game and Fish Department.
The San Rafael herd is down to an estimated eight animals, and the Sonoita herd is down to an estimated 18.
While the number of animals spotted can depend on weather conditions and other factors, Game and Fish doesn't consider either herd sustainable, and the agency plans to capture and transplant enough animals from the Chino Valley area, north of Prescott, to reinvigorate them.
But there are questions about whether the transplants will work if border fences and other pressures on the herds go unchanged.
Dan Millis, borderlands program coordinator for the Sierra Club, said he suspects not. However, John Millican, a project manager with the Arizona Antelope Foundation, said he thinks the border fence may actually have protected the few pronghorn that are left from being shot by poachers in northern Mexico.
Millican and Millis agree that better studies would help make the fence's impact clear.
Pronghorn (Antilocapra americana) aren't really antelope, which are found only in Africa and Asia. However, they're commonly called pronghorn antelope because they resemble true antelope in behavior and appearance. The pronghorn is the only surviving species of the antilocapridae family. They're considered the second-fastest land animal in the world, after the cheetah, with a top speed of more than 60 mph.
Environmental reviews skipped
After the Sept. 11, 2001, attacks, the Bush administration launched a massive expansion of the border wall and the Border Patrol. In 2006, Congress adopted the Secure Fence Act, and the Department of Homeland Security began contracting to build or reinforce fences in key areas along the U.S.-Mexican border, including in Arizona. Between the budget years 2008 and 2011, Customs and Border Protection spent $1.2 billion to build nearly 300 miles of fencing and roads along the U.S.-Mexican border, including areas around the Huachuca Mountains where the two pronghorn herds live.
To get that fencing up quickly, the Bush administration issued waivers of environmental- and endangered-species-protection laws and scrapped the environmental-impact studies and reviews that normally would have been required.
"We wish we had more scientific studies to point to," Millis said, "but the Department of Homeland Security has a poor environmental record. Borderwide, there's been very little funding for studies and habitat restoration and little of the due diligence that needs to be done."
Customs and Border Protection signed an agreement in 2009 with the Department of the Interior to fund up to $50 million in studies and projects along the border. The following year, the agencies launched $6.8 million in studies and projects along the Southwestern border. These included building a fish barrier in the San Bernardino National Wildlife Refuge, restoring habitat for long-nosed bats in Organ Pipe Cactus National Monument, and surveying and monitoring jaguars in southern Arizona.
Customs officials couldn't immediately identify further spending on border mitigation efforts.
Several studies that have been completed — on species such as the desert bighorn sheep in California and the cactus ferruginous pygmy owl — show that the habitats the animals need to thrive have been further fragmented. The chief causes are habitat loss due to development, habitat change from invasive plant species, the fences, the new roads along the fences and the increased Border Patrol presence.
Customs and Border Protection declined to discuss mitigation efforts in southeastern Arizona, but pointed, in a written statement, to the recovery efforts for the Sonoran pronghorn as “an example of our commitment.” The statement added that the agency “is fully engaged in efforts that consider the environment as we work to secure our nation’s border.”
Game and Fish tried twice — unsuccessfully — last winter to capture pronghorn near Chino Valley, using a quarter-mile-wide V-shaped trap leading to a corral, Paxon said. Officials decided against using a helicopter with a net gun because the mortality rate for the animals can run to 20 percent, vs. 3 to 4 percent using the corral traps, he said.
The captures have been postponed until next year, said Amber Munig, big-game supervisor for Game and Fish. Because the herd there spends much of its time on federal lands, the delay gives Game and Fish time to do a survey and gain permission from the federal Bureau of Land Management.
Munig said their goal is to transplant enough animals to boost the San Rafael and Sonoita herds up to at least 50 pronghorn each.
Munig said that while she couldn’t speak to the impact of the border fence, “We are looking at habitat issues and fragmentation in that area within Arizona.” The department has been working for years with other state and federal agencies, the Arizona Antelope Foundation and local ranchers to restore habitat in the areas used by the two herds, removing invasive species such as cheatgrass and juniper that squeeze out the native plants the pronghorn eat, she said.
Millican, who worked for 30 years for Game and Fish before joining the antelope foundation, said tackling another kind of fencing also has been key to connecting the fragmented areas where the pronghorn live. Arizona’s range lands are crisscrossed with barbed wire, old and new. That’s an issue for pronghorn, which shy from roads and, though fast, are not good jumpers, Millican said.
“Even when they’re really pressured, they prefer to go under a fence,” he said. But the lowest strand of older fencing, typically 6 to 8 inches off the ground, doesn’t give them enough clearance. So a major focus is working with landowners to replace the lowest strand of barbed wire with smooth wire 16 to 18 inches off the ground, which will keep livestock in but let the pronghorn through.
Millican agrees with the Sierra Club’s Millis that the border fence causes issues with other species moving back and forth. For the pronghorn, though, he said, “We have protections in the U.S.; there aren’t a lot of protections on the Mexican side.”
He said he’s confident that with proper habitat management on the U.S. side, the border fence won’t stop the herds from thriving again.
Millis, meanwhile, argues that other agencies and groups shy away from criticizing the Department of Homeland Security because “people don’t want to mess around with security issues.”
But he said there’s no question that the border walls harm the environment, “and now Arizonans are stuck with the costs of cleaning up the mess.”