The scientific investigation with Bonnie at the National Zoo was supported in part by a grant from the David Bohnett Foundation and complements field studies of wild orangutans, where differences have been noted in the call repertoires between populations. A strength at Great Ape Trust is the ability of its scientists to conduct simultaneous studies on both captive orangutans and wild orangutans on the Indonesian island of Sumatra at the Ketambe Research Center, where Wich is research co-manager.
"Bringing captive and field research together is an unharvested field," Wich said, "and it offers great potential to Great Ape Trust."
The research also builds on earlier investigations by ape language pioneer Dr. Sue Savage-Rumbaugh a scientist with special standing at Great Ape Trust, and others on the ability of great apes to imitate human speech. Specifically, Savage-Rumbaugh's 1991 investigation centered on whether the bonobo Kanzi, a member of the colony of bonobos now living at Great Ape Trust, might have structurally different vocalizations than bonobos in another group. In a 2004 study, Savage-Rumbaugh looked at whether Kanzi was attempting to imitate human speech.
The results of these studies did enlarge scientists' appreciation of the plasticity in primate sound and vocal learning and indicated that primates might have some plasticity to produce completely new sounds, Wich and his colleagues wrote.
The new findings reopen the door on such research.
"One of the main things we do not understand yet is the evolution of speech," Wich said.
Wich will present the findings on Dec. 18 at a scientific symposium on orangutan genetics at the University of Zrich, Switzerland.
|Contact: Al Setka|
Great Ape Trust of Iowa