© Adriano Lameira  |
Puji, a wild female orangutan of 16, was observed making and hugging a leaf doll at Ketambe Research Station in Sumatra. This leaf-doll making behavior, rarely seen and sparsely mentioned in literature, may be culturally learned among wild orangutan populations. © Adriano Lameira, used with permission.
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Students of Dr. Serge Wich document novel behavior among wild Sumatran orangutans at Ketambe Research Center
Des Moines, Iowa – May 22, 2008 – The findings of two Great Ape Trust of Iowa-supported students studying wild orangutans could tell scientists more about social learning and aspects of culture among populations of Asia’s only great ape.
The students, Adriano Lameira of Portugal and Madeleine Hardus from the Netherlands are assigned to the Ketambe Research Center in Sumatra as part of their Ph.D. programs at Utrecht University in the Netherlands. They are in Iowa for a month-long visit to Great Ape Trust to review their findings with scientist Dr. Serge Wich, research co-manager of the Ketambe program since 1997.
Lameira and Hardus are to present data obtained from field studies on orangutan vocalization and feeding habits during the 22nd congress of the International Primatological Society (IPS) to be held this August in Edinburgh, Scotland.
Lameira’s research compares orangutan vocalization across populations on the islands of Sumatra and Borneo, the only places on Earth where endangered wild orangutans remain, to determine if cultural traits influence vocal behavior. Hardus is following individual orangutans and monitoring their feeding habits as part of a study to determine how orangutans cope with logging, which has destroyed much of their habitat, and whether the diet available in logged areas is sufficient to meet orangutans’ nutritional needs. For comparison purposes, Hardus collects data in both selectively logged and unlogged areas of Sumatran rain forest.
Significant for Lameira was the documentation of a novel vocalization used by a female orangutan to call her infant, which he will present publicly for the first time at the IPS symposium in Edinburgh. In her yet-to-be published research, Hardus observed and videotaped a female orangutan as she hunted and then shared a meal of a slow loris with her daughter. The finding is interesting not only because it is rare for female orangutans to share their food source with their offspring, but also because it is uncommon, though not unheard of, for orangutans to eat other vertebrates.
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Madeleine Hardus is collecting data on orangutan feeding habits as part of her work at the Ketambe Research Center in Sumatra, where wild orangutan populations have been continuously studied since 1971. Photo courtesy of Adriano Lameira.
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Wich said that though the students are focusing on different aspects of orangutan cognition and behavior, their research often intersects to reveal greater understanding of the origins of culture and language, key aspects of Great Ape Trust’s scientific research program, and how they are transferred among different populations of apes.
"It could very well be that Adriano’s research will highlight certain differences between populations in vocalization," Wich said. That’s important, he said, because "we still have a major job to do in explaining why there are differences in populations.
"If you look at behaviors in different populations," Wich continued, "there are differences that resemble differences in human culture. Are the mechanisms behind the behavioral variation between orangutan populations the same as those in human culture?"
The inquiry into various aspects of orangutan culture is marked by a sense of urgency and the need to collect the information as wild orangutans become more rare. If habitat loss and other threats against orangutans are not abated, the red apes could be the first type of great ape to become extinct in modern time. With the acute loss of forest habitat, "a lot of differences in vocalizations have probably already been lost, which makes us less aware of the richness of their culture," Wich said.
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Adriano Lameira recorded a unique vocalization used by a wild orangutan to call her infant and will present the information to the International Primatological Society in August. Photo courtesy of Madeleine Hardus.
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He compared that with the loss of dialects in language among human populations. "You lose part of what orangutans are, just like losing an indigenous culture is a loss to what it means to be human," he said.
Scientists are limited in their ability to study social learning of vocalizations in wild ape populations, Wich said, but questions can be answered among captive apes at facilities such as Great Ape Trust by recording the vocalizations of apes coming from different captive populations to see if transfers occur.
BACKGROUND INFORMATION
Great Ape Trust of Iowa is a scientific research facility in southeast Des Moines dedicated to understanding the origins and future of culture, language, tools and intelligence. When completed, Great Ape Trust will be the largest great ape facility in North America and one of the first worldwide to include all four types of great ape – bonobos, chimpanzees, gorillas and orangutans – for noninvasive interdisciplinary studies of their cognitive and communicative capabilities.
Great Ape Trust is dedicated to providing sanctuary and an honorable life for great apes, studying the intelligence of great apes, advancing conservation of great apes and providing unique educational experiences about great apes. Great Ape Trust of Iowa is a 501(c) 3 not-for-profit organization and is certified by the Association of Zoos and Aquariums (AZA). |
Great Ape Trust is certified by the Association of Zoos & Aquariums
