National Geographic : 1989 Oct
NAIOAL GEOGRPHIC MAGAZINE: GEOGRAPHICA Bird Control Uses ... What Else... Birds! oronto's Lester B. Pearson Inter national Airport is using falcons to drive other birds off its runways, where they are a serious hazard. Dominic Di Carlo, a master falcon er, roams the runways with his trained falcons, routing out gulls, pigeons, Canada geese, snow buntings, and other avian hazards. Di Carlo is in radio contact with the airport control tower and can be on the spot of a bird invasion in less than ten minutes. His falcons rarely kill but are sufficiently terrifying to frighten away other birds for hours. In fact, he says, the hundreds of gulls that hang around the airport "are so wary of the falcons that now they fly away when they see my van." The falcons can't fly in heavy rain or severe wind, so falconers, including those at the Canadian Forces base at Trenton, Ontario, also use traditional bird-control methods such as firing harmless explosive devices near bird infested runways or playing tape re cordings of bird distress cries. But Di Carlo says that birds stay away longer when his falcons are used. No major airport in the United States routinely uses falcons, says Mike Harrison, wildlife biologist for the Fed eral Aviation Administration. Strict regulations -in the interest of prevent ing cruelty to animals-limit U. S. air ports to traditional measures. Tiny Step up Mountain, Big Step for Navigation The researchers used navigational satellites circling the earth. They used computers crunching vast chunks of numbers. They climbed Washington's Mount Rainier to plant. radio receivers on the summit. And when they finished, they had a new fig ure for the elevation of the mountain: Instead of rising 14,410 feet, it is actually 14,411.1 feet above sea level. PETERSIBBALD It may not seem like much, but to those who demonstrated the global positioning system that measured the elevation of Mount Rainier, the fact that the new measurement is so close to the old one indicates that the new system works. According to Stephen DeLoach, a civil engineer for the U. S. Army Engi neer Topographic Laboratories and a project consultant, the system uses a series of Defense Department satel lites "to determine exactly where you are." It will work for anyone with the necessary receiver, says DeLoach: "a soldier, a tank, a ship, an aircraft," or, fairly soon, the driver of a car. For a Male Rattlesnake, Life Is Full of Troubles Pity the male prairie rattlesnake as he slithers his way along the Conti nental Divide in Wyoming. His home territory is dry and cold-only about 95 frost-free days a year - and his favorite prey, the deer mouse, is widely dispersed and exists only in small popu lations. In midsummer, when he wants to mate, fewer than half the females in the vicinity may be receptive. David Duvall of the University of Wyoming, who has been studying these snakes with support from the National Geographic Society, believes that because of the lengthy cold sea sons females may require two or even three years to produce offspring, NGSPHOTOGRAPHERJAMES L. AMOS making many of them unavailable for mating each year. Duvall and a colleague, Michael B. King, find that both sexes spend mid May to mid-July searching for food. But after both shed their skins, males spend the remaining warm days search ing for a mate, while females continue to hunt. "Females are so widely dispersed that males compete in searching for a mate," Duvall says. "Instead of fight ing, they try to outrace each other to a receptive female. Only half find even one female each year." Those who fail to mate don't take it badly. They just go back to their dens and start over the next year. Vial of Anointing Oil Found in Israeli Cave And Zadok thepriest took an horn of oil out of the tabernacle,and anointedSolomon. I KINGS 1:39 he Bible contains many such references to the installation of kings of ancient Israel by anoint ing them with oil. An archaeological team excavating a cave at Khirbat Qumran, near the Dead Sea, recently SVEN NACKSTRAND,AGENCEFRANCE-PRESSE found a small earthen vessel filled with an oil that may have been destined for such a purpose. A copper scroll discovered in 1952 is believed to be a list of items from the Temple in Jerusalem that fearful Jews had hidden in this cave and others nearby as the Romans approached the city. In A.D. 70 the Romans destroyed the Temple. Vendyl Jones, a Texas archaeologist who joined the team from the Hebrew University of Jerusalem, said that the vial was wrapped in a nest of palm fibers. Team members first thought the flask was filled with dirt, but when they took it outside, a dark substance began to seep out. Chemical tests revealed most ofthe components used in making the oil, though one plant has not been identified. Jones says the Jews may have hidden the oil because the Romans valued it as a perfume.