Primate archaeology: old science gets new members
Archaeology, the study of ancient cultures and their artifacts, has always been confined to the technology of humans and direct human ancestors. However, a new study recently published in the journal Nature examines the benefits of expanding the field of archaeology to include non-human primates.
Until a half-century ago, humans were thought to be the only species capable of making or using tools. The foresight, imagination, and dexterity required for tool use and construction were thought to be absent from the non-human primates. That all changed in 1960 when Jane Goodall observed wild chimpanzees modifying sticks in order to extract termites from mounds. Now, not only are chimps and humans the only apes known to use tools, but gorillas and orangutans as well. Even monkey species such as the bearded capuchin and the long-tailed macaque have been reported to habitually use stones as tools in the wild.
The long-tailed macaque is one of the most recent primates that has been identified as a tool-user. Photo by: Rhett A. Butler.
A “tool” is an object that is used for a specific task. Some examples of tools used by non-human primates include branches that have been modified by gorillas for use as postural supports, stones used as hammers and anvils by chimps to crack nuts, and stones used by capuchins to dig for tubers and process vegetation such as cactus.
Other species of mammals and birds are also known to use tools. Sea otters use stones to open shellfish, New Caledonian crows modify sticks to probe for insects in the the ground, and bottlenose dolphins have been observed using sponges to protect their snouts when probing ocean sediments for spiny fish.
By extending the field of archaeology to include non-human primates, researchers hope that collaboration between primatologists and anthropologists will be encouraged and result in a more thorough understanding of primate evolution. They believe that artifacts found at sites that are occupied by certain species known to be tool-users would be invaluable as behavioral cross-references when analyzing the stone tools left by extinct hominids. Certain patterns of wear on stone tools have long puzzled paleoanthropologists; perhaps the causes of such wear could be revealed by observing tool-use among extant primates.
Primate archaeology could also be a boon to primatology in general. In recent years, the number of primate species observed using tools in the wild has increased greatly. A focus on trace evidence for technology among non-human primates is very likely to lead to many more discoveries of tool-use in species which, like the bearded capuchin ten years ago, were never before thought capable.
Citation: Michael Haslam, Adriana Hernandez-Aguilar, Victoria Ling, Susana Carvalho, Ignacio de la Torre,
April DeStefano, Andrew Du, Bruce Hardy, Jack Harris, Linda Marchant, Tetsuro Matsuzawa,
William McGrew, Julio Mercader, Rafael Mora, Michael Petraglia, Helene Roche, Elisabetta Visalberghi
& Rebecca Warren. 2009. Primate Archaeology. Nature. DOI: 10.1038/nature08188
Male chimps use meat to seduce
(04/07/2009) Male chimpanzees who share meat with females over a long period of time have a better chance of mating, according to a new study published in PLoS ONE. Studying chimps in Tai National Park, Côte d’Ivoire, researchers from the Mac Planck Institute for Evolutionary Anthropology observed that female chimps have sex more frequently with males who have shared meat with them at least once as opposed to males who never share.
Dedicated rock-throwing chimp proves longterm planning
(03/10/2009) Biologists have suspected for a long time that animals other than humans are capable of making plans for future events, but it has proven difficult to show conclusively. However, a new study in Current Biology claims the first unambiguous evidence of an animal premeditating. Mathias Osvath of Lund University in Sweden has spent a decade observing a male chimpanzee in a zoo collecting stones, making them into concrete discs, and then throwing them at zoo visitors.
First photos of face-to-face mating by gorillas in the wild
(02/12/2008) Scientists have taken the first photos of face-to-face copulation by wild gorillas. The images were captured in Nouabalé-Ndoki National Park in the Republic of Congo.