It’s not just about the jaguar.
When the federal government finishes building nearly 240 miles of new border wall across much of Southern Arizona, damaging impacts on a wide range of mammals, birds, fish and insects are expected, say environmentalists, researchers and U.S. Fish and Wildlife Service officials.
Both endangered and nonendangered animals are likely to take a hit, as far west as the Sonoran Desert’s remote reaches on the Cabeza Prieta National Wildlife Refuge and as far east as the wetlands of the San Bernardino National Wildlife Refuge near the New Mexico border, they say.
Impacts are predicted to fall upon “charismatic megafauna” as visible as the endangered Sonoran pronghorn and the common black bear and mountain lion — and on obscurities such as the endangered San Bernardino springsnail and the Sonoyta mud turtle.
The concerns come as U.S. Customs and Border Protection builds 63 miles of 30-foot-high border wall in Pima and Cochise counties for $1.3 billion. It has also built 47 miles in Yuma County, and recently announced plans and obtained Defense Department funds to build the remaining miles in those counties and Santa Cruz County. The wall is being built to keep out drug smugglers and undocumented immigrants, the Trump administration has said.
These impacts will occur in an area of borderlands long recognized to be one of the most biologically diverse areas of the U.S., wildlife experts say.
Among other things, researchers from 10 U.S. and Mexican universities have said that Pima and Cochise counties are among the country’s most diverse counties. Southern Arizona’s borderlands harbor at least 878 known species, the U.S. Fish and Wildlife Service has said.
Direct impacts that experts say are likely to be or could be caused by the new wall include:
- Mammal populations could be reduced and in a few cases eliminated on either side of the border.
- Wildlife habitats will be fragmented, lost and degraded.
- Gene flow between species separated by the wall could be interrupted, potentially reducing their chances of long-term survival.
- Small animal populations could be isolated from one another.
- Some birds, including the once-endangered pygmy owls, won’t fly over the 30-foot-high barrier.
- Some birds and bats could slam into the wall and die.
- Among concerns about mammals, University of Arizona biologists and the Fish and Wildlife Service are concerned, for instance, that the wall will hurt migration of the Sonoran pronghorn, but Arizona Game & Fish says the pronghorn aren’t crossing the border much now.
- Imperiled fish and amphibians could disappear due to groundwater pumping near ponds. These include Yaqui topminnow, Yaqui catfish, Yaqui chub, beautiful shiner, Sonora chub, Chiricahua leopard frog, Tarahumara frogs, Sonoyta mud turtle and Quitobaquito pupfish.
- Monarch butterflies, whose Western population is 5% what it was in the 1990s, could be hurt by the wall disrupting foraging and egg-laying behaviors, the wildlife service said.
- The San Bernardino refuge and its surrounding valley support the highest documented diversity of bee species in the world — 550. Lighting along a new wall would “negatively alter their behavior, survival and pollinating capacity,” San Bernardino manager Bill Radke wrote to CBP.
Some of the most wide-ranging concerns about the wall’s impacts were raised nearly a year ago by U.S. Fish and Wildlife Service officials in written comments to Customs and Border Protection. The Star obtained these comments last week, from the Sierra Club, which got them through the federal Freedom of Information Act.
In those June 28 comments, a top service official, Seth Willey, wrote that up to 16 federally protected endangered and threatened species could be living in the areas impacted by the new wall sections in Pima and Cochise counties, along with seven other “at-risk” species that don’t have federal protection.
Overall, increased human presence interrupts wildlife behavior that can lead to changed movement, foraging, hunting, water access, mating and rearing young, along with changing circadian rhythm, cell and DNA repair and other physiological stress reactions, wrote Willey, acting assistant director for ecological services in the service’s Albuquerque regional office. Over time, all those impacts can affect wildlife’s fitness and ability to survive, he wrote.
Put another way, the wall threatens to bring “ecological disaster,” said Louise Misztal, director of Sky Island Alliance, a Tucson-based conservation group.
“The wildlife need to be able to move around to reach food, water and mates, and they need connected open space to survive, and the wall destroys their ability to do that,” Misztal said.
Border agency says it will be responsive
The wildlife service’s 2019 comments contained a long list of recommendations for steps the wall builders could take to limit or compensate for their impacts. The CBP says it’s willing to listen.
CBP officials, who obtained waivers of many federal environmental laws to expedite the wall’s construction, say they’re already taking many steps to try to monitor, mitigate and compensate for impacts. For one, they’ve conducted hundreds of wildlife surveys along the wall’s planned route over the years.
The surveys have been done not just for the latest sections of wall, but for building the existing, much shorter vehicle and pedestrian fences along the border, past fence replacement projects, and for repair and maintenance work associated with border infrastructure, the agency said.
Environmental surveys for the latest stretch of wall construction were to begin this spring.
CBP plans to include or create openings of various sizes in the wall to allow wildlife to pass through. For small mammals and other small creatures, the openings will be about 8 inches wide, about twice the size of normal openings between the steel bollards that form the wall. For larger mammals, the openings’ size hasn’t yet been released.
CBP said it will release an environmental stewardship plan at the end of May that will sum up the wildlife surveys’ findings, analyze environmental impacts and lay out “best management practices” to try to counteract the impacts.
The agency is taking public comments until May 15 on the next 74 miles of wall construction planned. To solicit comments, it reached out to more than 1,000 groups, agencies, individuals and tribes, CBP official Paul Enriguez said in a recent court document replying to a lawsuit against wall construction. The agency has held virtual “site visit” webinars for other federal agency officials to discuss wall impacts.
While public comments won’t stop the wall projects, the CBP uses these comments to take measures to try to mitigate the impacts, CBP spokesman Matthew Dyman said.
One example is that the agency recently used comments about water flows and floods in several waterways to create appropriate wall designs, he said. The designs will allow for continued flow of surface waters across the border and minimize the potential for debris buildup or backup of water during a 100-year flood, Dyman said.
Photographing borderlands wildlife
To better gauge the wall’s impacts, the Sky Island Alliance and a second conservation group, the Wildlands Network, have set up remote cameras to compile animals’ “before and after” use of the borderlands.
They have installed dozens of cameras there in the past few months. The Sky Island cameras cover 34 miles from the Patagonia to the Huachuca mountains, across the San Rafael Valley. The Wildlands Network’s cameras cover both sides of the border, in walled and soon-to-be-walled areas near the San Bernardino National Wildlife Refuge east of Douglas and in Sonora’s Peloncillo Mountains.
Since the cameras were installed, several thousand photos have documented dozens of mammal and bird species — 32 in the Sky Island Alliance photos and “several dozen” in the Wildlands Network photos, said Myles Traphagen, a Wildlands Network biologist.
The animals documented include mountain lions, javelina, bobcats, black bears, coatimundis, several skunk species, nocturnal great blue herons, mule and white tail deer, gray foxes, numerous bird species, cottontails and jackrabbits, Gould’s wild turkeys and badgers.
And while most animals caught on these cameras are common and none so far are endangered, the placement of this wall will be “a major evolutionary experiment to see if there are large enough populations on both sides of the border to survive the wall and all the other stresses they are subject to,” said Emily Burns, lead scientist on the alliance’s camera project.
With the weather warming and drying due to long-term climate change, she said, “it will never be more important for these animals to move from habitats and move across the landscape.”
Biologists voice concerns
The fate of imperiled fish are a major concern for biologists who have examined the wall’s construction plans.
At the San Bernardino wildlife refuge near the New Mexico border, wildlife service officials and other biologists are concerned that groundwater pumping to supply the wall’s concrete will dry up a pond now housing endangered fish species Yaqui topminnow, Yaqui catfish, Yaqui chub and beautiful shiner.
Impingement of water flow in a neighboring water course known as Black Draw “from border activities and construction” could also harm the fish, the wildlife service’s 2019 comments said. Groundwater pumping is also expected to trigger extinction of the San Bernardino springsnail that occurs on in one spring on the refuge, retired wildlife service biologist Jim Rorabaugh told the Star.
Other problems that could affect protected fish, plants and other wildlife include “alteration of natural water flow, reduced water absorption and infiltration, limiting water recharge capacity, impacting wetlands or uplands with pollutants, and increasing siltation within seasonal and perennial watercourses,” wrote San Bernardino Manager Bill Radke in separate comments to the CBP last year.
Also at San Bernardino, Rorabaugh is concerned that as the wall’s concrete footer takes months to cure while under construction, it will leach toxic materials into surface waters, “likely creating toxic conditions for fish and other organisms.”
Far west in the Atascosa Mountains, Rorabaugh has similar concerns about impacts of wall construction on rare species such as the Sonora Chub, Chiricahua Leopard Frogs and Tarahumara Frogs.
In California Gulch there north of the border, endangered Sonora Chub live only in a small tinaja, a pool formed in a rocky hollow, and perennial pools at the border that Rorabaugh fears will be dried up by wall construction. The frogs live in neighboring Sycamore Canyon although not at the border, but Rorabaugh said he’s concerned that toxic leachates from concrete used in wall construction could still hurt them.
Endangered turtle’s future at stake
Still farther west at the Quitobaquito pond at Organ Pipe National Monument, University of Arizona biologist Michael Bogan said he’s concerned that groundwater pumping for the wall in that area could dry up waters that now house the endangered Sonoyta Mud Turtle, which lives only there and in the Rio Sonoyta just south of the border.
The CBP has agreed not to pump groundwater closer than five miles from the pond. Two University of Arizona hydrologists have said that even more remote pumping farther away could lower its water level.
Today, only about 140 mud turtles or so live in Quitobaquito, while the Rio Sonoyta population has dropped greatly from 1,000 a few years ago, he said.. Another water-dweller facing the same plight is the endangered Quitobaquito pupfish, which also lives only in the pond and the Rio Sonoyta, the wildlife service letter said.
“Any additional straws in the aquifer are just another problem,” said Bogan, an assistant aquatic ecology professor. “The turtles are barely hanging on now.”
A secondary problem is that once the wall is finished, the turtle populations can’t cross the border and interbreed, Bogan said.
“If there is no genetic mixing in between the two, each population is weaker,” he said.
Questions about borderlands breeding
These questions about borderlands breeding apply to mammals too, biologists and environmentalists said.
Besides the jaguar, they’ve expressed major concerns about the wall’s impacts on the endangered ocelot, of which five have been photographed in the U.S. since 2010. The black bear is abundant in the U.S., but much less so in Sonora, stirring concerns among that a wall could reduce the Mexican population even as he and others worry that it will cut ocelot populations on this side of the border.
There’s also the endangered Sonoran pronghorn, which lives in Cabeza Prieta National Wildlife Refuge and in northern Sonora’s El Pinacate y Gran Desierto Biosphere Reserve in northern Sonora. The populations are fairly isolated from one another by a major Mexican highway near the border. Since the Arizona Game and Fish Department started radio collaring them in 1980, only one collared pronghorn has been documented to cross, said Arizona Game and Fish Department Assistant Director Jim DeVos.
But using remote cameras, UA PhD candidate Miguel Angel Gragaeda has documented several pronghorn living in Sonora north of the highway, as close as a half-mile south of the border. That means that they likely have crossed into Arizona, he said. He is currently trying to get the Mexican government’s transportation agency to install an overpass along the highway to let pronghorns cross.
While DeVos’ agency doesn’t see the wall as a major concern for pronghorns, Gragaeda and the wildlife service do. Replacing a much shorter vehicle barrier at the border there with a 30-foot fence will restrict pronghorn movements and range, and “move them in the direction of being entirely dependent” human-assisted border crossings, the wildlife service’s June 2019 comments said.
“I think we should keep these types of areas open for wildlife,” Gragaeda said. “This corridor is crucial for the management and conservation of this endangered species.”.
Bees and butterflies
In his comments on the wall, San Bernardino refuge manager Radke noted that the refuge and the surrounding San Bernardino Valley support the highest documented diversity of bee species in the world — 550. If lighting is built along the new wall, that will “negatively alter their behavior, survival and pollinating capacity,” he wrote.
Monarch butterflies, whose western population is 5 percent of that of the 1990s, could also be hurt by the wall, the wildlife service said. Now being considered for federal protection as threatened, they often winter in southern Arizona instead of their usual wintering rounds on the California coast and Mexican evergreen groves.
In this area, the monarch typically feeds and lays its eggs in native plants standing lower than 30 feet high, meaning that a border barrier could interrupt its foraging and egg laying, the service said.
Other native butterflies living in the border area are smaller than the monarchs, live there year-round, have less developed wing muscles and tend to fly low, avoiding heights over 15 feet, the service said. Those that rarely fly more than 10 feet high, “are particularly vulnerable to isolation and impediments to connectivity” with other butterflies across the border, the service wrote.
In wildlife service official Willey comments last year to CBP, he concluded on a positive note, however, saying, “We appreciate your efforts to engage landowners and managers, and we are ready to work together to minimize the projects’ potential impacts.”