Blocking Biodiversity: Why a "Great Wall" Might Not be Great for AZ Wildlife

Mar 16, 2017

President Donald Trump has vowed to build an impenetrable wall along the U.S.-Mexico border to keep people from coming into this country.   But there’s concern for the non-human traffic that traverses that line.  Maya Springhawk Robnett of the Arizona Science Desk reports.

In the Sonoran Desert, the loudest animal sound one might hear is the braying of a wild burro.  But like the other desert wildlife, they’re skittish of people.  On the outskirts of Yuma, Arizona, friendlier (domesticated) wild burros can be found on a farm.

Sugar, Laura Merrill's adopted wild burro
Credit Maya Springhawk Robnett

Laura Merrill adopts burros as pets.  When Merrill took one burro, Sugar, out of the pen and, Sonny, the brown one with the white legs, was left behind, Sonny started whining.  She began running back and forth along the gate, desperately looking for a way out to get to her companion.

Sonny’s behavior is indicative of the way wildlife experts say most animals treat barriers: they don’t know how to get around them.  That’s why a proposed uninterrupted wall along the U.S./Mexico border worries wildlife experts.

Near Douglas, Arizona, Kelly Glenn-Kimbro’s family has owned the ranch on the American side of the vehicular barricade for more than six decades.  Though the Glenns are Trump supporters, Glenn-Kimbro said they think this is the only barrier they need.

“We don’t want a wall.  It isn’t going to stop ten people.  We saw a funny thing at Walmart in Douglas right after Trump was elected.  My daughter and I saw a truck with Sonoran license plates, going to Mexico, with twelve ladders on it,” Glenn-Kimbro laughed, “And we were like, ‘Oh my gosh! This man’s going into business!’”

"We don't want a wall. It isn't going to stop ten people." - Kelly Glenn-Kimbro, Rancher

The Glenns are part of a ranchers’ conservationist outfit called the Malpai Borderlands Group.  23 years ago, the group was more concerned with preserving wide open spaces.  Now, Bill McDonald, the Executive Director, said they have another focus.

“I think we’re very concerned that a wall would stop natural migration corridors for a lot of these animals.  There’s a big difference between a barrier that has gaps in it that allows wildlife to go through,” McDonald gestured to the post-on-rail in front of him, “and one that doesn’t.”

Arizona Game and Fish Department officials focus on wildlife populations and don’t typically respond to individual reports of wildlife injuries.  So when an injured animal is brought in or reported on the border, they must rely on volunteers.

A Red-tailed Hawk being rehabbed at the Arizona Western College campus aviary. (Note: Vigil is not wearing the proper gloves to handle the hawk in this photo.)
Credit Maya Springhawk Robnett

Cecilia Vigil, doctor of veterinary medicine in Yuma, is one of those volunteers.

Outside a small aviary on the Arizona Western College campus, she cared for a red-tailed hawk brought in with symptoms of poisoning.  Initially, she didn’t think he’d make it.  Vigil worries more animals might not make it.

“You put those walls up and they can’t cross-pollinate,” Vigil explained. “They can’t pass those genes and mix them up.  Once you lose that biodiversity, it affects the population in very devastating ways.”

"Once you lose that biodiversity, it affects the population in very devastating ways." - Cecilia Vigil, Doctor of Veterinary Medicine, Arizona Western College

Vigil is referring to fragmentation—or the splitting of animal populations, which causes in-breeding and cuts them off from their primary food and water sources.  

Numerous endangered species could be affected by a border wall, including jaguars.  Three jaguars have been spotted in Arizona since 2015; only seven have been documented here in the last 21 years.

Bryon Strom for the Yuma Sector Border Patrol isn’t ignorant of wildlife’s plight.  He took part in the recovery program for one endangered species, the Sonoran Pronghorn Antelope.  But Strom thought the current barriers on the border aren’t a major problem for wildlife.

"The right fence is in the right place..." - U.S. Border Patrol Agent Bryon Strom

“Where there’s a will, there’s a way,” Strom said, “And where we’ve done environmental impact studies the right fence is in the right place to allow that to happen.”

37 environmental laws were waived in order to put up the existing barriers on the border, including the requirement to perform environmental impact studies.  Strom said the Border Patrol conducted its own assessments.  But Dan Millis with the Sierra Club calls them “window dressing.”

“Some watered-down environmental assessments have been written up and rubber stamped.  It’s not enough to protect the environment,” he said.

Much of the border is shaped by rivers, so sections of concrete wall have led to floods in desert areas and Millis said an uninterrupted wall would also cut off many animals’ access to water.

"Mountain lions don't throw ropes over the wall. Deer are not able to construct a ladder and go over the wall." - Dan Millis, Sierra Club

“For the Border Patrol to say that ‘where there’s a will, there’s a way,’ is really emblematic of how people respond to the wall, not wildlife.  Mountain lions don’t throw ropes over the wall.  Deer are not able to construct a ladder and go over the wall,” Millis explained.

Officials with the U.S. Border Patrol and the U.S. Game & Fish Department said they expect to have a say in theconstruction of any new barrier on the border and those same officials seemed confident it won’t be a solid, uninterrupted concrete wall.  So until it’s set in stone (or cement), the animals of the border—for the most part—remain binational citizens.

A sign on the dirt road a few miles from the Douglas, Arizona border orders: WATCH FOR ANIMALS
Credit Maya Springhawk Robnett