High Tech Goes Wild
Back when Katy Payne was just starting to study elephants, "high technology" meant that the bags researchers used to collect elephant droppings were made of plastic, not paper, allowing them to make it back to the research camp without springing a leak. These days, the goal of Payne's research--learning more about the elephants of central Africa--hasn't changed, but the tools have. In April, Payne and her colleagues will position 10 microphones and a videocamera around a forest clearing in the Central African Republic to record elephant sounds and behaviors as the animals congregate. By matching audio to video, the researchers hope to create an "elephant dictionary": this call means a female is in estrus, this trumpet corresponds to juveniles sparring. Then Payne, a research associate at Cornell University, and her team will Velcro 12 microphones to trees deep in a forest in Ghana. They hope to figure out the size, composition and behavior of this little-studied herd, all without having to actually find and watch the elusive animals. They hope to warn farmers when elephants approach crops--and alert wardens when they hear poachers' rifles. "The acoustic approach," says Payne, "gives us a lot more information than visual surveys."
It's almost a law of nature: the weaker a species's hold on life, the tougher it is to learn enough about it to haul it back from the brink of extinction. Pandas live in the most remote bamboo forests of China; sea turtles paddle to uncharted depths. Until recently, scientists have had to use intelligent guesswork to fill in the blanks in their knowledge: if a gray whale was sighted off Baja in January and off Alaska in June, researchers drew a line and hoped that it came close to the whale's actual migration route. Now, technology--from GPS transmitters to camcorders mounted on seals--is giving biologists virtual access to the remotest places on Earth and the animals that live there.
More than anything else, the new gizmos are pinpointing the hangouts of threatened species so that governments know where to focus conservation efforts. In the Sulu Sea, Malaysia and the Philippines protect some islands where green turtles breed. But after depositing eggs on the beach, the females swim in unprotected waters. So in 1998 biologists glued satellite transmitter tags to turtles' shells to track the endangered reptiles' whereabouts. The tags transmit a signal to a NOAA satellite, and scientists download the data. "The most devastating effect on turtles in this area is from trawlers that scoop them up in nets," says Michael Stuwe of the Smithsonian Institution. "But if we know how far from the beach the turtles go, we can try to influence the authorities to make sure patrol boats keep trawlers out."
A project in the Gulf of California uses different technology for the same goal. To find out where the threatened porpoise called the vaquita hangs out, scientists are about to begin underwater acoustic monitoring by dragging microphones off the back of a sailboat. That could give them a better fix on where gill nets, which trap and kill vaquita, should be banned.
The most advanced undersea ears belong to the U.S. Navy, which built a vast network of underwater microphones to detect Soviet submarines. A few years ago the Navy began sharing with marine biologists the sounds their microphones detected. It had long been biological dogma that whales were scarce in the open ocean, but the Navy was picking up whale songs thousands of miles from land. Christopher Clark of Cornell launched a project to "mine" the sea with high-tech acoustics. He packs microprocessors and hydrophones into an 18-inch sphere and drops it overboard. After a few weeks, Clark retrieves the "pop-up" by transmitting a signal that separates the unit from its anchor. His effort is helping Italian scientists learn where fin and sperm whales are surviving in the polluted waters of the Mediterranean.
China needs similar data to protect its pandas. Which microclimates, in the vast bamboo forests, do these endangered creatures live in? To find out, Andy Phillips of the San Diego Zoo has been teaching managers of China's panda reserves how to use the Global Positioning System of satellites to map the forests. Teams of 20 to 30 take readings with a GPS device, then record the soil type, vegetation and drainage at the spot. They match panda sightings to microclimates and plot them on a 3-D satellite-generated map.
Besides aiding conservation, technology is allowing scientists to study the behavior of animals that do their behaving out of sight. For 25 years, how and why seals dive as deep as 1,000 feet had been a mystery. To solve the puzzle, marine biologist Randall Davis of Texas A&M University worked with colleagues to develop a device that records time and depth while a camcorder mounted on a seal's head records where the animals go and what they do. The system showed that seals can sink without swimming, thus conserving oxygen and remaining underwater longer. Now Davis's team is putting its latest, hand-built, $15,000 device on the backs of Weddell seals in Antarctica. Why do the seals dive as deep as 600 feet to hunt? One reason is that they catch prey by swimming up through schools of fish, and by "silhouetting" their quarry against the ice.
In the Malay Peninsula, the way to protect elephants them seemed clear: get them away from farmers whose crops they raid. But many relocated elephants wandered back--a good way to get poached. When researchers attached satellite tags to relocated animals, they found that lone females seemed to make a beeline for home. Thanks to the satellite tracking, the researchers now know that to keep problem pachyderms from homing, they must be moved in mini-family units. If that works, then technology, so effective at nudging species toward extinction, might bring a few back.