ART, WILDLIFE, BORDER
April 2025
From Freedom To Fences:
Wild Life And The U.S.-Mexico Border Wall
Tempe, Arizona​
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A bear stands precariously on the U.S.-Mexico border wall -a stark reminder that while political lines may divide nations, they also divide ecosystems. The black bears in Arizona are crucial for the population in Sonora, Mexico, because the ones in Sonora are at great risk due to habitat loss and fragmentation. But the border wall severs their movement, Wildlands Network Borderlands Program Coordinator and zoologist Myles Traphagah explains at the SEJ 2025 Conference.
Southern Arizona zoologists from Wildland Networks, Sky Islands Alliance and Sierra Club have been monitoring wildlife in the borderlands since 2020 to try to understand what happens when nearly 70% of the Arizona-Sonora border is blocked off by a wall that’s 18 ft to 30 ft tall.
In 2022, cameras picked up a wolf that came out of the Gila River from the north that kept on pacing back and forth for three days along the border wall, but, unable to cross it, ended up going back where he came from and dying.
But that wolf isn’t the only animal severely impacted by the 760 miles of barrier separating the United States and Mexico, which almost blocks off an entire continent, those zoologists explained at the Society of Environmental Journalists’ [SEJ] 34th Annual Conference in Tempe, Arizona, on April 25.
“There are animals trying to cross as if their life depended on it,” Sierra Club researcher Erick Mesa said. “Finding them dead at the feet of the wall is common.”
The wall disrupts ancient migration corridors, threatening species like mountain lions, black bears, bighorn sheep, pronghorn, whitetail deer and mule deer, wild turkeys, desert tortoises and Mexican gray wolves, Sky Islands Alliance zoologist Eamon Harrity explained.
“All these species do not fit through the openings in the wall,” Harrity said. “Jaguars won't get through either.”
And if the United States wants to reestablish a population of jaguars, there cannot be a wall, journalist John Washington says.
The wall’s design—steel bollards spaced 4 inches apart or solid panels—prevents most animals larger than a bobcat from passing, though small 8.5-by-11-inch openings have allowed some female mountain lions to squeeze through, a feat researchers call remarkable but insufficient.
“For many species, those openings are the only way through the wall,” Harrity says. “But there’s only 19 in the entire barrier.”
At San Bernardino National Wildlife Refuge in Arizona, Wildlands Network zoologist Myles Traphagan observed many animals before the construction of the wall, but very few after.
“One skunk out of 1641 pictures,” he said. And ancient watersheds, bulldozed. “I mourn that damage, like if I had lost a loved one,” he said.
In 2021, the Sierra Club sued the Department of Homeland Security [Sierra Club vs. Biden], which secured open floodgates for two years at San Bernardino National Wildlife Refuge, few more little wildlife openings, some funds for conservation science and habitat restoration, and engagement in environmental planning before taking further wall construction actions.
However, challenges remain. The Department of Homeland Security controls wall modifications, and the new political shift could restart construction.
Recently, for instance, researchers learned that the new administration wants to build across the 27.5 mile-long San Rafael Valley, considered the last southwest U.S.-Mexico border network of wildlife connectivity.
The ‘Sky Islands,’ tall mountains in the Sonoran Desert where the San Rafael Valley lies, are one of the most biodiverse places on the planet. They are the northernmost range of the jaguar, and the place where many species’ northernmost and southernmost extents of migration range happens, the zoologists said at the conference.
“If we block this, it’s forever. We are going to lose so many species,” Harrity said. “Driven north by warming climates, species will run into a barrier that will prevent them from reaching climate refugees.”
“Catastrophic,” they all say, repeatedly.
But until the San Rafael Valley and the 63 miles of the Tohono O’odham Nation remain unwalled, there remains some hope for wildlife.