Paradise Lost

In September 2006 Congress responded to national outrage about our grossly porous southern border by voting in The Secure Fence Act. The law mandates the Department of Homeland Security (DHS) to construct 854 miles of double-layered fence along 35 percent of our southern border, from San Diego, California, to Brownsville, Texas, complete with roads, clearings, stadium-style lighting, sensors, cameras, and radar—a 21st century Maginot Line designed to repel the invading army of illegals. The Congressional Research Service reports that building the fence and maintaining it for 20 years will cost $49 billion. But there are other, greater costs.

Part of that “something” are the wild animals that depend on the Rio Grande for water and on the thin habitat corridors that thread through these borderlands for food, cover, and genetic viability. Although 95 percent of the valley is cropland, it is still one of the most biologically diverse areas in our nation.

Four climatic zones converge here. The temperate zone brings in species not seen farther south—northern mockingbirds and sugar hackberry, for example. The Chihuahuan Desert supplies species not seen to the east, such as thorny plants, cactus wrens, and pyrrhuoxias. The Gulf Coast contributes shorebirds and wading birds, and the subtropics provide species that don’t occur to the north, such as brown jays, red-crowned parrots, green parakeets, hook-billed kites, and clay-colored robins. The U.S. Fish and Wildlife Service has identified 11 distinct habitats in the valley. One reason they meet in south Texas is that there are no barriers for hundreds of miles. But that may be about to change.

My first stop was the 557-acre Sabal Palm Audubon Center, tucked against the Rio Grande in Brownsville. The center, a Global Important Bird Area, is visited annually by about 10,000 people who pump $6.9 million into one of the nation’s poorest communities. Each year Audubon educational programs bring nature to about 3,000 children who otherwise wouldn’t encounter it.

The center is part of an intense, 30-year cooperative effort by the Fish and Wildlife Service, Audubon Texas, Frontera Audubon, the Sierra Club, The Nature Conservancy, Friends of the Wildlife Corridor, the Texas Parks and Wildlife Department, Pronatura Noreste (a Mexican NGO), and the Mexican states of Nuevo Leon and Tamaulipas to set up a linear system of wildlife corridors to the river and between countries.

Thirty feet from the center’s parking lot I began seeing birds you won’t find anywhere much north of here. Pheasantlike plain chachalacas dipped and bobbed along branches and pathways, drowning out human conversation with their raucous calls. Green jays flashed their spectacular plumage. Couch’s kingbirds hawked insects. And hidden in the dense foliage of willows, mesquite, and acacias, kiskadees shouted their names. The center’s manager, Jimmy Paz, led me through a lush understory of such natives as Turk’s cap, coral bean, castor bean, David’s milkberry, and Barbados cherry growing beneath a canopy of huisache, guamuchil, great lead trees, and Texas ebony. We found buff-bellied hummingbirds, white-tipped doves, ladder-backed woodpeckers, a gray hawk, a Swainson’s hawk, a pair of white-tailed kites, and Altamira orioles.

The esteros—oxbow ponds discarded like empty wine bottles by the reeling river—held coots, pintails, blue-winged teal, mottled ducks, and least grebes so tiny they looked like windowsill gewgaws. Red-eared sliders glistened on floating logs, and solitary sandpipers and northern water thrushes patrolled mudflats. Gray-crowned yellowthroats had been extirpated in the United States, but three years ago they showed up again, and now they nest here. Yellow-green vireos, almost extirpated, now nest here, too. Surviving in this oasis of native habitat is America’s largest remaining stand of sabal palms, trees that, before the riverboat industry razed them for wharf pilings, cloaked the valley and gave the river its first name, Rio de las Palmas. Ocelots and jaguarundis have been seen here, and Paz has found jaguar tracks.

Ocelots, the only one of these critically endangered species for which there is decent data, are probably the most abundant of the three. They used to range through Texas and into Arkansas and Louisiana; now the U.S. population, confined to a thin band along the river, is thought to number no more than 100. By cutting off gene flow and thereby causing inbreeding, the fence will almost certainly eliminate all three cats north of the border, reducing our nation’s native cat species by half. Local cougars and bobcats will suffer grievously but survive. Canada lynx, found only in our northern states, will, of course, be unaffected—unless Congress decides to seal off the Canadian border, too.

Paz shrugged when I asked him where the fence would go. “They won’t tell us, but we think just north of our property,” he said. Later Audubon Texas executive director Anne Brown added this: “One of our huge frustrations has been lack of consultation and lack of any formal process to voice our concerns. That affects how we do our planning and budgeting. From what we’ve heard, we’ll have to close. We can’t figure a way to keep it open, because we’ll be cut off from the rest of the United States. Will we be insured? Will we receive city services? We can’t let Ernie [the caretaker] live here anymore.” The sanctuary and its unique plants and wildlife will be taken from the American people, and what survives will be, for all intents and purposes, ceded to Mexico.

A mile east of the Sabal Palm Audubon Center is The Nature Conservancy’s 1,034-acre Southmost Preserve, part of the same system of wildlife corridors. Here TNC’s Max Pons and Sonia Najera showed me some of the valley’s last Montezuma cypress. The preserve also sustains the nation’s second largest stand of sabal palms. Because the seed-filled fruit is relished by coyotes, the resourceful Pons propagates these trees by collecting coyote scats and planting the seeds he extracts from them.