August 14, 2013
Human Activity In Thailand Affects Macaque Ability To Use Stone Tools
Brett Smith for redOrbit.com - Your Universe Online
While some scientists are focused on the conservation of species, researchers from the Nanyang Technological University in Thailand have been focused on conserving species’ behavior, particularly those of the Burmese long-tailed macaque.
According to new research from NTU, published in Oryx — The International Journal of Conservation, the macaque’s use of stone tools is being threatened by human activity.
“Generally, when we think of conservation, we think of species preservation, but I think we must also be concerned with the preservation of rare and interesting behavior produced by animals’ cultures as well,” said Michael D. Gumert, a primate behavior expert at NTU. “Many animal species have unique traditions, and these traditions are fragile to disturbance. They require good conservation management of the habitats that foster these traditions.”
Burmese long-tailed macaques are a less prolific relative of the long-tailed macaques common to Southeast Asia. The Burmese macaques are found only in Myanmar and bordering areas of Thailand, and in some of these locations along the coast these monkeys use stone tools to crack hard-shelled prey, such as oysters, sea snails, and crabs.
On Piak Nam Yai Island, the research team found that human activity is altering the ecosystem and affecting the macaque’s tool use. These activities include harvesting of clams and oysters for food, the proliferation of rubber farms and the use of domestic dogs to protect the farms.
Because these macaques are forced to become more vigilant and seeing less of a food supply, they are spending less time and energy learning tool-using patterns from their elders.
“Traditions need safety and stability to properly develop, otherwise, the coasts just become a danger area that macaques must learn to avoid, rather than a stable learning ground for developing tool-use,” Gumert said.
The NTU researchers discovered that 88 percent of the more than 190 macaques on the island use stone tools on a daily basis.
“They have a fascinating lithic culture,” Gumert said. “These Burmese macaques are the only monkeys in Asia that use stone tools. Only two other primate species, out of several hundred in the world use stone tools – the chimpanzees in Africa and capuchin monkeys in South America.”
“Knowing about primate stone tool use has important implications to compare with early hominine tool use, as well as the origins of cultural behavior,” he added. “Studying traditions allow us to investigate the cultural capacity of animals.”
The NTU researchers said they hope to develop a long-term research program on the tool-using macaques in conjunction with Thailand’s Chulalongkorn University. Gumert said he also plans to set up permanent research sites around these animals for research and educational purposes.
“We should also explore into Myanmar, because we think the behavior may be more common there,” he said. “Macaque stone tool-use was first reported back in the 1880’s in the journal, Nature, by Alfred Carpenter, an English seaman. We need to get into Myanmar and see how the macaques have changed since a century ago.”
“These monkeys are extraordinary and a natural treasure to the Southeast Asian region,” he added. “I believe stone-using macaques will become a symbol of coastal preservation here, a symbol for protecting Thailand and Myanmar’s wonderful coastal ecosystems, and all that depends on them.”