Won't You Be a Good Neighbor? NMSU Researchers Study Oryx
Date: Aug. 15, 1997
Editor: D'Lyn Ford (505) 646-6528, dlford@nmsu.edu
LAS CRUCES -- You've seen them grazing along the roadside between Las Cruces and Alamogordo. The oryx -- those large, straight-horned African antelope -- seem to have adapted well to their new home on the White Sands Missile Range. But how are they getting along with the neighbors? Raul Valdez plans to find out.
Valdez, a wildlife scientist with New Mexico State University's Agricultural Experiment Station, recently began a research project to find out whether the exotic oryx are competing with native New Mexican animals for food. "Exotic or introduced species are categorized as either facilitators or competitors," Valdez said. "Facilitators don't decrease the availability of resources for other species, while competitors do."
Ninety-three oryx were released on White Sands Missile Range (WSMR) between 1969 and 1977. The New Mexico Department of Game and Fish initiated the release to earn additional money for the state through trophy hunting, Valdez said. WSMR was chosen as a release site where the oryx wouldn't compete with domestic livestock, and the population could be controlled with annual hunts.
"That population has grown to an estimated 1,500 to 2,000 animals, and annual hunts do keep the population in check on the missile range," Valdez said.
The problem is that the oryx aren't confined to just the missile range. They have dispersed approximately 100 miles in all directions to private land and land managed by the U.S. Army, National Park Service, Fish and Wildlife Service, Department of Agriculture, and Bureau of Land Management. Oryx have been sighted as far south as Otero Mesa on Fort Bliss and as far north as Sevilleta Wildlife Refuge near Socorro.
As their home range increases, conflicts arise when oryx come in contact with sensitive plant and animal resources, public recreation facilities and ecological research sites, Valdez said. With their sharp horns, oryx have attacked automobiles at White Sands National Monument. These exotic animals also may compete with mule deer and pronghorn for food that can be scarce in the Chihuahuan Desert. "We know from previous studies that, in a desert environment, pronghorn eat mostly broadleaf weeds and need shrubs like mesquite for shelter," he said. "We also know that mule deer eat juniper, oak and mountain mahogany." Now Valdez needs to find out what oryx eat and if they prefer the same environments as pronghorn and mule deer.
For the study, 15 oryx, pronghorn and mule deer will be captured, fitted with radio collars, and released. The animals will be monitored at least twice a month to determine movements and territorial area. "Both pronghorn and oryx are very territorial," Valdez said.
To determine food preferences, researchers will collect and study fecal samples from areas where the animals are observed. Scientists will determine the plant species composition of the fecal material and the frequency with which different plants appear in the animals' diets.
By studying the eating habits, seasonal movements and general behavior patterns, Valdez hopes to determine whether the exotic species can coexist with the native wildlife. The study is expected to take five years to complete. "Knowledge of oryx movement patterns and herd structure is important in planning their removal from unwanted locations," he said.