Golden-green grasses bent by the wind ripple to a dusky horizon rimmed with mountains. Beneath a brilliant blue Mexican sky, cattle chew placidly as vaqueros on horseback patrol nearby. It’s an idyllic scene, but it stands in sharp contrast to the struggle being waged to conserve the grassland beneath their feet—one of the most endangered habitats on earth.
These are the Chihuahuan grasslands, found scattered throughout the 175,000 square miles of the Chihuahuan Desert. Bits of grassland are found in extreme southeastern Arizona, southern New Mexico, and western Texas. But by far the largest portion lies in Mexico. The Chihuahuan grasslands are a shadow of what they once were, eroded by conversion to agricultural use and the creeping desert. All this has led to alarmingly steep declines among the approximately 30 species of birds that winter there.
“Migratory birds from Canada and the United States depend on Chihuahuan Desert grasslands during the nonbreeding season, which lasts up to 10 months,” says Arvind Panjabi, international program director for Bird Conservancy of the Rockies (formerly Rocky Mountain Bird Observatory). “These are the birds that nest in the Great Plains—sparrows, longspurs, and buntings. Sprague’s Pipit, Baird’s Sparrow, and Chestnut-collared Longspur are three grassland birds that are most sensitive to habitat loss on their wintering grounds.” The grasses provide food for the birds and protection from predators.
“The more diverse your wildlife the healthier your ranch and your ecosystem”
The destruction began when humans brought in cattle almost 500 years ago, which led to overgrazing as vast herds of these nonnative ungulates ate the grasses down to bare earth. Without the grasses, an aggressive front line of mesquite, creosote bush, and other tenacious scrub moves in. It’s called “desertification.” Without the grasses, cattle cannot survive either, so the ranchers hit rock bottom.
“I realized I was destroying an ecosystem,” says Mexican rancher Jesús Almeida. But Almeida and a group of other progressive ranchers are breaking with tradition. The Bird Conservancy of the Rockies is working with them on a different grazing strategy that not only preserves grasslands and wildlife, but also makes their businesses more profitable.
“The key is establishing a short-duration rotational grazing system,” explains Panjabi. Instead of letting cattle graze in the same pasture until all the grass is gone, some ranchers are now using small pastures for as little as a day or two and then moving the cattle to a new area. “This means that, on average, each pasture is only grazed for 8 to 10 days out of the year. The grasses get to rest,” Panjabi says. “In many respects, we’re trying to mimic the historic grazing patterns of the bison.”
Almeida says the grass cover on his ranch in the Mexican state of Chihuahua has increased by 60 to 80 percent. But is it working for the birds? It’s too early to tell because altered grazing and proactive scrub eradication have only been going on for a couple of years. The Bird Conservancy of the Rockies does have monitoring programs in place to see if bird populations rebound.