Chimpanzee dentistry

Tool use for corpse cleaning in chimpanzees

For the first time, chimpanzees have been observed using tools to clean the corpse of a deceased group member. A female chimpanzee sat down at the dead body of a young male, selected a firm stem of grass, and started to intently remove debris from his teeth. This report contributes novel behaviour to the chimpanzee’s ethogram, and highlights how crucial information for reconstructing the evolutionary origins of human mortuary practices may be missed by refraining from developing adequate observation techniques to capture non-human animals’ death responses.

Cathedrals, symphony orchestras, and iPhones: The cultural basis of modern technology

The distinctions drawn by Vaesen are plausible when we are comparing chimpanzees and human beings somewhere between the middle Paleolithic and the Neolithic. But since then new kinds of organization have vastly outstripped these neurological differences to account for the enormous advancement of human technology – from cuneiform to the iPhone – leaving our remarkable evolutionary cousins far behind.

The first case of dental flossing by a Japanese macaque (Macaca fuscata): implications for the determinants of behavioral innovation and the constraints on social transmission

We report the first case of dental flossing behavior by a Japanese macaque. We used cross-sectional data to assess the presence of this novel tool-use behavior at the group-level. Although this behavior was performed frequently by a central middle-ranking middle-aged female during her grooming interactions, and appeared at least four years ago, it remained idiosyncratic to its innovator, and until now has not spread to other group members. We examined the factors that may have favored this innovation, including the environmental context, the individual characteristics of the innovator, and the structural and functional aspects of the behavior. Group size, kinship, and dominance are socio-demographic factors that are likely to limit the opportunities for any group member to observe the innovator, and thus constrain the diffusion of this potential candidate as a new behavioral tradition. This is one of the rare studies to document the spontaneous appearance of tool-use behavior in primates under natural conditions. Identifying the determinants of innovations and the constraints on their diffusion within social groups of non-human primates is of special interest to understanding cultural evolution.

Tool use in a group of captive chimpanzees I. Escape

A group of 4 female and 3 male adolescent wild-born chimpanzees was observed for 7 months in an outdoor enclosure. Use of tools aimed at escaping from this enclosure is decribed, the two main techniques being the use of poles as ladders and sticks as pitons.