Elephants can hear through their feet
Researcher says ability more useful to animals in wild
Patricia Yollin, San Francisco Chronicle
May 19, 2007
Once a month, Caitlin O'Connell has a date with an elephant. The Stanford research associate lives in San Diego and the pachyderm resides in Oakland, but they don't let geography interfere with their relationship. It's a question of science.
O'Connell has discovered that elephants can hear with their feet. They are specialists in seismic communication, relying upon sound waves that travel within the surface of the ground instead of through the air.
She's been working with the animals since 1992, when she went to Africa for nine months and stayed for 14 years. Donna, an Oakland Zoo resident, joined her wild counterparts as a research subject in 2002. "It's been a very interesting voyage," O'Connell said.
She'll be talking about that journey tonight at the Oakland Zoo and Wednesday at UC Davis, where she received a doctorate in ecology.
"I'm hoping this will spur a lot more study with large mammals," said the 41-year-old O'Connell, whose book, "The Elephant's Secret Sense: The Hidden Life of the Wild Herds of Africa," came out in March.
She said most study of seismic communication among animals has been limited to small rodents and insects -- a world that O'Connell, with a master's degree in entomology, knew something about before she went to Africa and stumbled upon elephants.
"It was certainly serendipity that started this whole thing," said O'Connell, who was asked, when she volunteered at Etosha National Park in Namibia 15 years ago, if she wanted to work on a three-year program on elephants.
"It took me two seconds to say yes," said O'Connell, co-director with her husband of Utopia Scientific, a nonprofit devoted to conservation.
She was supposed to find ways to keep elephants out of farmers' fields. While observing them, she started to notice certain odd things. "Normally, they would hold their big ears out like a parabola and scan back and forth," O'Connell said. "But to detect distant noise and vocalizations, they'd freeze and lean forward and put weight on their front legs. Sometimes they'd even lift up a front foot. All of them would do this at the same time -- it was too coordinated to be a coincidence." The behavior sometimes occurred when another herd approached or a ranger drove by in his vehicle.
"On a most fundamental level, the research is showing elephants have a whole modality for communicating that we haven't thought about," O'Connell said. Her findings could contribute to elephant conservation and to a better relationship between people and pachyderms.
For example, an early warning system, perhaps using the sound of elephant footfalls, could either set off an alarm for a farmer or allow the beasts to flee before encountering humans. "It's very frustrating for farmers to live with elephants," O'Connell said. "A group of elephants can come into your field and eat your whole year's supply of food in one night."
She returns to Africa for two months every summer, accompanied by Oakland Zoo General Curator Colleen Kinzley, a few zoo colleagues and some Stanford students. This year, they're leaving June 8.
They usually study about 40 bulls and 200 females in 10 family groups. "To see the consistency of the characters is really fun," O'Connell said. The cast of regulars includes Winona, a feisty young female who has two cutouts in one ear that look like a "W." "She's a benevolent dictator," O'Connell said. "Another one is Margaret Thatcher. She's much more officious and chases the others away. Nobody else can drink at the water hole when she's there with her family." By contrast, 27-year-old Donna at the Oakland Zoo is "cooperative" much of the time.
O'Connell sometimes spends several days with her, working up to five hours at a time. The researcher sits at a table 5 or 10 feet behind three targets, with a computer and wires that connect to a metal plate the elephant stands on, with a 10-pound shaker attached.
When Donna correctly detects a vibration, she gets a treat, such as an apple, banana or alfalfa cube. If she makes a mistake, she only gets a "no, no, no!" from Kinzley. Failure can make her distraught, O'Connell said, while success will prompt her to prance around, make little noises and get "real perky."
Osh, the zoo's bull elephant, is also getting involved in the experiments, though he tends to be rambunctious and is getting a concrete platform with rebar under it. "Donna is much more amenable to playing the game and not messing with everything," O'Connell said.
She said there is a world of difference between zoo elephants and those in the wild, in terms of responding to sound waves in the earth. "Donna and Osh are living off 580," she said. "They're captive elephants. They don't pay attention to vibrations because they don't have to."
O'Connell said she was met with a good deal of skepticism when she first learned that elephants listen with their feet. "People didn't believe it," she said. "It took a lot of time to get people on board. It wasn't something they'd considered with large mammals."
She said data on surface waves, and how far they travel, was scarce because seismologists filter them out when they're measuring quakes. It took many follow-up experiments to demonstrate pachyderm capabilities to dubious scientists. "People are just amazed," O'Connell said. "Even now, we don't know what the outer limit is."