Conservation groups study wildlife movement at border wall in Arizona

Conservation groups have set up cameras in the San Bernardino National Wildlife Refuge in Southern Arizona to study the border wall’s effects on wildlife movement, including whether larger mammals are using the open floodgates during the monsoon to cross the border.

Sky Island Alliance and Wildlands Network are expanding their research of wildlife in the U.S.-Mexico borderlands with dozens of remote wildlife cameras installed in June along 2 miles of the border wall in the small wildlife refuge east of Douglas.

Sky Island Alliance previously started the Border Wildlife Study in March 2020 with 58 cameras from the Patagonia Mountains through the Huachucas, including one of the few areas of the Arizona border where there isn’t a border wall.

This new study looks at the San Bernardino Valley, which the groups say is an important wildlife migration corridor between the Rocky Mountains and the Sierra Madre Occidental, which was impacted by the 30-foot-tall border wall.

While the border barrier cuts off most larger wildlife from their migratory patterns, animals can still cross the border part of the year through a series of 1.7-meter-wide floodgates, which are open during the monsoon season.

The project’s cameras recorded more than 48,000 photos of more than 20 mammal species during the first month of the study. About 9% of animals that were seen near the floodgates crossed through them, including a mountain lion, bobcat and javelinas.

It’s too early in the study to determine why only 9% of the animals are using the floodgates to migrate, but one reason could be that it’s a relatively new structure that the animals are still adjusting to, says Eamon Harrity of Sky Island Alliance.

If the floodgates were open year round, it would give the animals a better opportunity to get used to using them, he said.

“If we learn large mammals can cross the border through open flood gates, we can create wildlife pathways all along the U.S.-Mexico border to help them reach vital food and water,” he said. “It’s a simple policy choice to open these flood gates and help species like mountain lions and black bears find their historic migration routes once again through the wall.”

Customs and Border Protection could not immediately respond to whether leaving the gates open year-round was a possibility.

There are also numerous small openings in the border wall in that area that are about the size of a sheet of paper. Sky Island Alliance has seen small animals such as a jackrabbit or a roadrunner use those openings but only animals so small they could probably fit between the bollards in the border barrier anyway, Harrity says.

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Larger animals such as black bears, mountain lions and jaguars typically migrated through this border region seasonally in search of mates to reproduce or for food and water. More than 90% of critical habitat for jaguars along the U.S.-Mexico border in Arizona has been intersected by the border wall.

“The most immediate effect is for the first time in the history of this continent, more or less, there’s a barrier to movement,” Harrity says. “So these wide ranging animals are suddenly cut off from what might be a seasonally available resource on either side of the border.”

A longer-term effect of disrupting annual patterns of migration may be shrinking animal populations, making them more susceptible to disease and local extinction events, he said.

This study is some of the only work being done to understand the impact the Arizona border has on wildlife and looking at the floodgates to understand their potential as wildlife corridors and wildlife crossing points, Harrity says.

When the wall was constructed in 2020, the federal government waived all environmental laws using the 2005 REAL ID Act, which among other things allows the secretary of Homeland Security to waive laws for faster border infrastructure construction.

No environmental reviews were conducted to study the border wall’s impact on wildlife at the refuge because all those laws were waived, says Michael Dax, a program director with Wildlands Network.

“Now, with this vital research underway, we can begin to understand how the border wall affects animal populations,” he said.

The study just has a couple months worth of data now, but the groups plan to monitor the wildlife in the refuge for at least three years, documenting wildlife movement through the seasons when border wall flood gates are both open and closed.

“I think the long term implications of this wall are perhaps quite severe if no actions are taken to increase the openings or the ability for animals to cross,” Harrity said.