Ancient death and modern survival.

Ancient death and modern survival

Over the past 10,000 years, the California condor has vanished from the skies of its once large habitat in the western United States and Florida. Today, Gymnogyps californianus is near extinction, and all 27 remaining animals are living in captivity as part of a breeding program (SN: 4/25/87, p.263). This month, however, a paleontologist who studies ancient condors announced that prehistoric clues from caves in the Grand Canyon and other locations might help those who are seeking to reintroduce G. californianus to the wild.

In the most recent centuries, G. californianus populated a small area along the Pacific coast of Oregon and California, but scientists don't know when and why the condors disappeared from their inland habitats. Though some have suggested that inland G. californianus survived until quite recently, a study published in the Aug. 14 SCIENCE concludes that condors in the Grand Canyon vanished about 10,000 years ago, at the end of the Pleistocene epoch.

Steven D. Emslie of the University of Florida at Gainesville based these conclusions on radiocarbon dating of condor tissue and bones found in caves in Arizona, New Mexico and Texas. He says this is the first use of radiocarbon dating on a large series of condor fossils, and it reveals that no samples are younger than 9,500 years old.

Within the Grand Canyon cave, Emslie also found fragments of a horse, a bison, a mammoth, a camel and an elephant. This leads him to believe that G. californianus preyed on the carcasses of these larger mammals, all of which disappeared from this region at the end of the Pleistocene. If so, says Emslie, "then their [G. californianus's] disappearance from most areas at the close of the Pleistocene may be traced to a loss of food source.'

Some scientists have proposed releasing condors into the Grand Canyon as part of a recovery program, but Emslie says his findings suggest it is unlikely these birds would survive unless they were regularly supplied with supplemental food.

Meanwhile, in Ventura, Calif., Joseph Dowhan, who is coordinator of the Condor Recovery Program, told SCIENCE NEWS that none of the captive condors successfully mated during the breeding season this year, although Dowhan is sanguine about next year's season, which begins in January.