Santa Ana National Wildlife Refuge is home to a small population of endangered ocelots Tom Smylie, USFWS

For the past two years, President Trump’s idea for a wall on the U.S.–Mexico border has existed as little more than a psychosocial blueprint. At his rallies and other public events, Trump riles up the crowd with bellowed promises to “build that wall,” a guaranteed applause line—or, to be honest, a scream line. And when paired with a second promise to “make Mexico pay for it,” an even larger roar of approval erupts from Trump’s fans.

But now the wall seems to be finally, er, getting off the ground. (Please pardon the pun—and if not, I’ll just pardon myself! Apparently that’s a thing now.) One sign of the wall’s passage from the abstract to the concrete: on Wednesday, the U.S. House of Representatives began debate on H.R. 3219, the “Make America Secure Appropriations Act,” which, if passed, would provide $1.6 billion for “physical barrier construction” along the border.

Another sign is what’s quietly taking place down in Texas.

At the southern tip of the Lone Star State, along the banks of the Rio Grande, the Santa Ana National Wildlife Refuge sits on little more than 2,000 acres. Among birdwatchers, it’s a bucket-list destination, widely recognized as one of the best spots in the country for seeing a wide variety of species—more than 400 of them, by some counts—in a relatively compact setting. It lies at the nexus of two migratory routes (one north to south, the other east to west), and birds flock here from all directions. The refuge also marks the northernmost range for many avian species of Central and South America.

A small and vulnerable population of endangered ocelots also takes refuge in Santa Ana. These leopardlike felines with unusual markings once roamed throughout the lower Southwest. According to the U.S. Fish and Wildlife Service, only about 50 ocelots remain on American soil, nearly all of them restricted to a tiny swath of South Texas. The cat’s survival and recovery depend on its ability to hunt and raise its cubs in a protected environment―such as the Santa Ana National Wildlife Refuge. Habitat loss and inbreeding (which is often the result of habitat loss) have already weakened the few dozen ocelots left in Texas. The best way for the population to regain its genetic diversity and increase its numbers, wildlife experts say, is through mating with ocelots in northern Mexico—via connected habitat exactly like the one found here.

President Trump is about to make that much more difficult.

Over the past six months, at the behest of the U.S. Customs and Border Protection agency (CBP), federal officials and hired contractors have been conducting preliminary work at the refuge for the construction of the first portion of the border wall. They didn’t choose this federal land at random. Ninety-five percent of the land along the Rio Grande in Texas is either state owned or privately owned; the president could start building his wall on other people’s property, but the legal process would be lengthy and complicated.

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Once news of the project leaked (thanks to an anonymous official disturbed by the secretive manner in which the process was unfolding), a spokesman for the CBP confirmed on the record that the agency had received a waiver to begin testing soil samples, a first step toward groundbreaking on the 18-foot-high barrier. The same anonymous official told a reporter from the Texas Observer that construction could begin as early as January and that it would entail clearing land, building roads, and erecting numerous surveillance stations and light towers up and down a three-mile stretch—effectively turning what many call the crown jewel of our national wildlife refuge system into a miniature military installation.

“The border wall is a bad idea from start to finish,” says Andrew Wetzler, a wildlife specialist and deputy chief program officer at NRDC. “It’s bad for people, it’s bad for local economies, and it’s bad for the wildlife that depend on intact, open space to survive. Wildlife refuges are the last places we should be chopping up with walls.”

But wait: it gets worse. Sources say that President Trump is planning to cite the REAL ID Act, a 2005 law pertaining to national security, in order to skirt an environmental impact study that would otherwise be mandatory for any project of this size and scope on federal land. And by citing this same act—which was passed when the country was still reeling from the 9/11 attacks—the Trump administration could essentially sidestep the Endangered Species Act, which would typically prohibit the destruction of habitat belonging to an endangered species like the ocelot.

In short, by starting his wall on federal land, Trump gets to avoid having to deal with private landowners and their issues. And by waving a copy of the REAL ID act around as he sets about destroying pristine wildlife habitat, he avoids having to deal with the American public, too. No friction from concerned ranchers or other stakeholders. No environmental impact studies. No public comment period.

And it’s all for a three-mile stretch that any ambulatory human could easily avoid in favor of an un-walled stretch on either side of it. All for the fragmentary symbol of a barrier.

But for an ocelot, it’s a very real barrier, indeed, one that could wall it in to extinction.

onEarth provides reporting and analysis about environmental science, policy, and culture. All opinions expressed are those of the authors and do not necessarily reflect the policies or positions of NRDC. Learn more or follow us on Facebook and Twitter.