The thorn forests on Lower Rio Grande Valley National Wildlife Refuge in Texas provide the endangered ocelot with one of its last vestiges of habitat in the United States. Knowing that only an estimated 50 ocelots remain in the United States, refuge managers are concerned that oil- and gas-related pipelines, and roads transecting the forest give the ocelot’s dominating competitors—coyotes and bobcats—inroads to one of the species’ last footholds.
The ocelot specializes in hunting in dense, almost impenetrable vegetation where larger predators have limited access. This wild feline—twice the size of a house cat—once ranged across Texas, southern Arizona and into Louisiana and Arkansas, but now its only U.S. presence is in the southern tip of Texas.
Lower Rio Grande Valley’s thorn forest is transected by pipelines that are periodically cleared of vegetation, threatening to degrade part of the cat’s fragile habitat. As in many aspects of oil field management, the most economical practices to maintain oil and gas pipelines may be detrimental to wildlife. Oil and gas operators traditionally use herbicides to clear vegetation over pipelines, creating a 10- to 30-foot-wide corridor that reduces the risk of line damage from plant roots and allows monitoring for leaks. Now, Lower Rio Grande Valley Refuge Manager Bryan Winton is reaching out to energy companies that operate on the refuge and beyond to encourage them to mow pipeline corridors. Killing native vegetation with herbicides encourages invasive plants to infiltrate the refuge. Herbicides can also degrade water quality as heavy rains can wash them into streams or wetlands. (Read full article in PDF.)