The Gemsbok Oryx gazelle, commonly referred to as simply the “Oryx,” is a majestic large antelope that is native to southern Africa’s arid or semi-arid open grassland, scrub, open woodland, and desert. Oryx have adapted well to the extreme climates of the Kalahari semi-desert and the Namib Desert. While an Oryx’s body temperature can rise to 113 degrees Fahrenheit, a temperature that would kill most mammals, Oryx have a network of blood vessels that serve as a cooling system to keep their brain from overheating. Whereas Oryx will drink occasionally from streams or waterholes, they can also survive for days or even weeks without drinking water. Oryx get much of their water from feeding on grasses, forbs, and melons, which have also adapted for the desert climate by storing water. Because Oryx are desert-adapted, they breed year-round. Other mammals usually breed during the rainy season. The Oryx’s main predators in Africa are lions, hyenas, and wild dogs. These predators ensure that only about 10% of Oryx calves make it to their first birthday.
The experience with the African Oryx in New Mexico illustrates the problems of introducing exotic species into new ecosystems. Fewer than 100 Oryx were introduced into the White Sands Missile Range in New Mexico between 1969 and 1977 by the New Mexico Department of Game and Fish. This was done in order to create a new big game hunting opportunity in a region where few big game were available to hunt. The Oryx’s adaptations to harsh desert conditions in Africa have allowed them to be extremely successful in the arid, but less-harsh, conditions of the Chihuahuan Desert of New Mexico. In New Mexico, the Oryx have more rivers for hydration and the desert plants of the southwest, such as yucca, buffalo gourds, and tumbleweeds. Furthermore, the Oryx have no natural predators in the American Southwest, as mountain lions and coyotes have proven no match for the Oryx’s speed. Whereas it was originally estimated by scientists that the Oryx population would grow to only about 500 to 600 and remain in the Tularosa basin, by 2007 there were roughly 5,000 Oryx, and they have now spread to both the San Andreas and Sacramento Mountains.
The spread of the Oryx out of the White Sands Missile Range has caused concern to farmers, park service employees, biologists, and environmentalists because of overgrazing on farmlands and damage to the fragile desert habitat that is preserved in the White Sands National Monument. To keep the Oryx out of the White Sands National Monument, the National Park Service erected more than 60 miles of fencing. There is a consensus that the Oryx population of New Mexico needs to be greatly reduced and that Oryx should be kept within the White Sands Missile Range, although there are disagreements as to whether this should be achieved through shooting the animals, deploying contraception, or using other means. Many feel that the Oryx should have never been brought to New Mexico.
2. Which of the following conclusions can be reasonably drawn from the second paragraph?
Scientists’ predictions are not always accurate.
The greatest danger of introducing exotic animal species is the genetic pollution resulting from hybridization.
Farmers generally are against introducing exotic species into new ecosystems.
Exotic animal species are usually introduced into new locations to increase hunting opportunities.
As desert species need such great adaptations to survive to their harsh environments, they are more likely to be successfully introduced into new ecosystems.