The Lower Rio Grande Valley NWR: Five Percent Remaining
Near Mcallen, Texas
Of all the native habitat that once lined the lower Rio Grande, only five percent survives. The rest has been converted: to citrus groves, to irrigated farmland, to suburbs and highways and maquiladora parks. What remains is fragmented into small parcels scattered along two hundred miles of river, too small and too isolated to sustain the full range of species that depend on them.
In nineteen seventy-nine, the United States Fish and Wildlife Service began a program designed to address this directly. The Lower Rio Grande Valley National Wildlife Refuge was established not as a single protected block but as a corridor project: a deliberate effort to buy land whenever it became available, piece by piece, and stitch together a connected strip of native habitat from Falcon Dam near Laredo to the Gulf Coast. Today the refuge encompasses about ninety thousand acres in four counties, though those acres are non-contiguous: land units scattered across the landscape, connected more by intention than by geography.
The biological argument for the corridor is straightforward. The Valley is where three of North America's major flyways converge, making it one of the most important stopover habitats on the continent for migratory birds. It also lies at the northern edge of several tropical species' ranges. The thorn scrub, the resacas, the riparian forest: each habitat type supports different species that require all the others to function as a system.
The refuge supports nearly five hundred bird species, three hundred butterfly species, and twelve hundred native plant species. It protects some of the last remaining habitat of the ocelot in the United States. And it is ongoing: the refuge is still acquiring land, still extending the corridor, fifty years after the first parcels were purchased. The five percent that remains is not a fixed number. The refuge is working to make it larger.
