National Geographic : 2006 Sep
A boojum gracefully bows toward the desert floor, as if to offer its flowers back to the earth. Millions of these strange succulents dot central Baja California, living from rain to rain, as have the inhabitants of the Sonoran Desert for millennia. fences and other barriers, especially highways, discourage the shy pronghorn from migrating in search of what water and forage remain. "We had a sample of nine pronghorn wear ing radio collars in 2001 and 2002," says Curt McCasland, Cabeza Prieta's assistant refuge man ager. "Nearly every one died. One female spent the last few days of her life right next to High way 85"-a busy route through Organ Pipe Monument. "It had rained on the other side, but she wouldn't cross." If McCasland, refuge biol ogist Michael Coffeen, and others hadn't kept packing coolers of water into the wilderness for the staggering animals to find, perhaps none would have survived. The aid efforts didn't stop there. With support from private wildlife orga nizations, staff from the refuge and Arizona Game & Fish Department fenced a square mile of Cabeza Prieta range, added water, and brought in pronghorns from both Mexico and Arizona to breed in captivity. Today, the U.S. population is back up to 60 plus, including 14 adults and their offspring in an enclosure. In the first light of day, Allen Zufelt of the game department climbs a nearby hill and locates the animals with a telescope, focusing on a doe with twin fawns, the buck that fathered the young, and other captives until he is satisfied that all are healthy. The next step in his daily routine is to walk the four-mile perimeter to be sure no openings have appeared in the woven wire fence or the electric fence in place around that. A double layer of security was called for to keep out coyotes, bobcats, and mountain lions and discourage illegal border-crossers from breaking through. "We get thousands of undocumented aliens a year coming through the refuge and Organ Pipe," Zufelt tells me. The people smugglers, labeled coyotes, and the drug smugglers, or narcotraficantes,have built up networks with lookouts, satellite phones, night-vision goggles, and modified high-speed vehicles that have cut tracks all through previ ously remote terrain. Some days, my naturalist treks have led me to more improvised shelters 148 NATIONAL GEOGRAPHIC . SEPTEMBER 2006 and abandoned gear-not to mention Border Patrol squads and Black Hawk helicopters than wildlife. It's like being in the midst of a guerrilla conflict. Watching smoke rise from wildfires to the north, Zufelt calls it a sign of what some con sider the most serious yet overlooked modern threat to the ecosystem: hardy grasses and weedy herbs from the Sahara and deserts in the Mediterranean and Asia. A few, like buffel grass, were introduced as livestock forage. Forming a ground cover dense enough to fuel roaring blazes in an ecosystem never subject to wildfire before, the invaders could eventually replace slower growing, woody plants-in other words, the very cactuses and small trees that define the Sonoran Desert. Pronghorn mothers and fawns have joined in a nursery band just across the fence. The does move away in an effortless trot when they catch our scent. We catch theirs as the white rump hairs puff out in warning, releasing an almondy aroma from special glands. Zufelt points to a Harris's hawk nest with young atop a saguaro. "A pair of foxes dug into the pen," he recalls. "Half a dozen pronghorn bunched up and start ed chasing the foxes. One fox busy looking over its shoulder at a doe ran near this saguaro and was whacked on the side by an adult hawk defending the nest. That fox must have been thinking, Man, I've got to get outta here." R ain has once again refreshed the arroyo pools. Except for a Gila woodpecker in flight, nothingstirs on the sun-stunned mountainsidesabove. Yet rain didfall, and more is predicted.Mirages dance over the valley, making it seem that the green plants shimmeringbelow are merely an illusion. And yet rainfell. It always will, sooner or later.And thousands of years of wild invention will come into play to extract the most from every drop. D Visitor Alert A geotourism map with tips on Sonoran nature and culture is due early in 2007. See nationalgeographic.com/travel/sustainable.