National Geographic : 1990 Oct
I1 A A GEOG AP MAA Z IE [OCTABE 1990l Andean Birds Test Skies for California Condor he test release of Andean condors in California may pave the way for the reintroduction of the state's native condors, now living only in captivity and totaling 40 birds. The suc cess of the program proved that zoo raised condors can survive in the wild. Between 1988 and 1990, 13 South American fledglings, raised in captiv ity in the U. S ., were released by the U. S. Fish and Wildlife Service and the Los Angeles Zoo in the 1.75-million acre Los Padres National Forest, near Santa Barbara. The vultures quickly learned to soar (right); at maturity their wingspan will reach ten feet, slightly wider than the California con dor's. The young birds found the food set out to aid their survival, and ten of them adjusted successfully. They will eventually be recaptured to augment populations in South America and to prevent crossbreeding after the Cali fornia condors are released. The hatching this year of eight Cali fornia condors has made biologists optimistic that these giants may return to the California skies by 1992. Harnessing Greenhouses to Purify Sewage hile not yet ballyhooed as a tourist attraction, a waste Streatment plant on Cape Cod is Drawing city officials from around the world to see a sunlit army of organisms turn waste into clean water. DANNBLACKWOOD "Many of the chemicals used in con ventional waste treatment actually add to the pollution of the water supply," says John Todd (below left), an environmental inventor. "My system moves sewage by gravity through a series of tanks in a greenhouse, where hundreds of species of plants and ani mals break it down naturally." In April the town of Harwich, Mas sachusetts, population 9,000, began using Dr. Todd's system to handle a third of its septage-the highly concen trated waste collected from septic tanks. The facility takes as much room as a conventional treatment plant but should operate at lower cost. In a step-by-step process, bacteria digest the organic matter and convert ammonia into nitrates on which algae and duckweed thrive. Zooplankton and snails feed on the algae, fish eat the zooplankton, and floating plants soak up the leftovers. Bulrushes, cat tails, and water hyacinths render toxins harmless by breaking them down into constituent parts. Heavy metals, such as copper and lead, are absorbed into the tissues of trees to be transplanted outside. By-products of the cleanup system can be sold, he says, including deco rative plants and minnows for bait. In Louisiana, Mississippi, Florida, and California, natural systems using aquatic plants now process sewage in man-made, open-air lagoons. Dr. Todd's greenhouse concept makes this kind of natural sewage treatment possi ble in the North as well. Glasnost Produces a Death Ray for Locusts Soviet scientist and a U. S . scien tist, friends for 15 years, are team ing up with laser weaponry to fight an old enemy of human kind, locusts. In swarms half a mile thick, the insects quickly defoliate hun dreds of square miles. Crop damage in Africa and the Middle East can reach 200 million dollars a year. Peter A. Franken of the University of Arizona was hosting Vladilen S. STEVEMCCURRY,MAGNUM Letokhov from the Institute of Spec troscopy in Moscow when they came up with a plan. "Remote sensing from high-flying U-2 aircraft can locate the locusts by their trail of defoliation," says Dr. Franken. "Far from any human settlements, we'll aim a ten-foot-wide laser beam from an airplane or helicopter, roast ing the swarm. This would be less harmful to the environment than using poisonous chemical controls." Soviet and U.S. officials have expressed enthusiasm for the plan.