19 October 2015
Increasingly researchers are using particles of plants trapped in dental calculus to reconstruct the food choice of past populations. Plant microremains in dental calculus have been used to identify plant use by hominins such as Neanderthals and Australopithecus sediba. This information on plant use has been eye opening because often there is no alternative means to identify plant use- a major part of diets.
Unfortunately inferring plant use from dental calculus is challenging because few studies have attempted to correlate dental calculus data to dietary records. Studies have confirmed that the microremains in dental calculus are food traces, but little work has been conducted to assess how representative this information is. Without these details, dental calculus studies provide data that are difficult to contextualize.
A new study stemming from collaboration between the Plant Group and the Institute’s Department of Primatology published in Scientific Reports presents the first characterization of the dietary record in dental calculus. The study used chimpanzee
dental calculus from closely studied wild chimpanzees from the Taï Forest (Côte d’Ivoire) to show plant microremains can accumulate in dental calculus as long-lived dietary markers. These chimpanzees have been closely monitored for decades as part of the Taï Chimpanzee Project, a Max Planck funded project since 1997. Detailed dietary records stretching back to 1991 allowed researchers for the first time to match microremain data to quantitative long-term diet dietary history.
The study, one of the first to confirm that the dental calculus record can provide a substantial picture of diet found that the representativeness varies according to the type of evidence. More robust phytoliths documented diet superiorly than more fragile starch grains. Some of these foods teach us something new about chimpanzees. For example, the presence of Coula nut starches in the dental calculus of some individuals demonstrated the presence of nut cracking- a trait characteristic of West African chimpanzee culture. “What we can learn from this finding,” states Robert Power, author of the paper, “is that dental calculus is probably more useful but also a more complicated reservoir of diet than previously thought.”
Robert C Power, Domingo C Salazar-García, Roman M Wittig, Martin Freiberg, Amanda G Henry. 2015. Dental calculus evidence of Taï Forest Chimpanzee plant consumption and life history. Scientific Reports | 5:15161 | DOI: 10.1038/srep15161