Gambel's quail are among the most striking of West Texas birds. They're richly patterned in gray, brown and white. And the male is crowned with an impressive black top-knot.
Their habitat in our region is limited. But while other quail species have declined, Gambel's populations are strong.
Gambel's quail are found mostly in the Sonoran Desert of Arizona and Mexico. But their range extends across the Southwest, from California to the the Big Bend of Texas.
They prefer areas that are lush by Southwestern standards – from foothills canyons to desert draws and arroyos. Even in extended drought, these areas can sustain woody brush and green forbs – flowering, herbaceous plants.
They are a game bird, and hunting Gambel's quail is good business in West Texas. Historically there hasn't been much information on their range. Mike Sullins, a Texas Parks and Wildlife biologist, conducted a pioneering study in the late 1990s.
Sullins found Gambel's in the rough draws around the Sierra Diablo, near Van Horn and Sierra Blanca, and in agricultural fields in Dell City. And what was the favored habitat for Gambel's? It was along a narrow band – the Rio Grande and its floodplain.
Annaliese Scoggin is a Texas Parks and Wildlife biologist who works with Sullins.
“In West Texas, Gambel's quail are typically found in two habitat types,” Scoggin said, “one being the river corridor, along the Rio Grande, and the other the inter-mountain basin-bolson formations, where they're typically found in the deeper gravelly washes, with more brush cover. The majority of the Gambel's population is found along the Rio Grande.”
The brush is critical to every element of the Gambel's life. It provides cover from predators. Like all quail, those predators include mammals, snakes and raptors.
But in the lowest elevations of the Big Bend, hawks and rattlers aren't the only hazards. In summer, daytime temperatures along the Rio Grande regularly rise above 110 degrees. Access to shade becomes a matter of life and death.
“Research has shown that quail are pretty sensitive to high temperatures that they experience during the heat of the day, especially on hot, open ground,” Scoggin said. “So the thermal cover provided by the heavy brush is really important, especially when you're talking about the river corridor in West Texas. You always hear the weather reports, where it's 80s in the mountains and 90s in the flats, and 110 on the river. That brush becomes really important to provide the thermal cover and shade to protect the birds during the heat of the day.”
Sullins focused on the Gambel's diet. He found that more than a third of that diet were seeds of forbs.
Sullins' findings confirmed earlier studies on the bird in New Mexico. The single largest food item for Gambel's was Russian thistle. That's an invasive plant – one most of us know by another name.
“In both the past studies in New Mexico and Mike Sullins' study in West Texas, they found that Russian thistle was one of the primary food items,” Scoggin said. “That's what everybody calls tumbleweed, of course. It's nice to know that there's at least one good use of tumbleweed, as a food source for the Gambel's quail, even though it's a nuisance for farmers and other folks.”
Gambel's chicks hatch in May and June. They're “precocial” – meaning they're mobile and they feed themselves from birth.
“They're entirely dependent on insects for their food source for the first few weeks,” Scoggin said. “But they're really opportunistic. They take whatever they come across, whether it's beetles, grasshoppers, termites, ants. Whatever they find on the ground that's available in large numbers is what they're typically dining on. If we have a lot of dry weather, and the insect numbers aren't there, we're going to have very low chick survival, no matter what conditions the the habitat's in.”
Since the 1980s, bobwhite and scaled quail populations have declined steadily. But not the Gambel's quail. Their numbers have held steady. And their range is growing.
In winter 2014, the El Carmen Land and Conservation Company transported more than 200 quail from Candelaria, Texas to a property just east of Big Bend National Park. And the birds have flourished there.
The Rio Grande plays many roles for West Texans – an international border, a boating destination, water for drinking and irrigation. But for the region's Gambel's quail, it's irreplaceable. The river and its banks are home.