Reliable long-term individual variation in wild chimpanzee technological efficiency.

Variation in the efficiency of extracting calorie-rich and nutrient-dense resources directly impacts energy expenditure and potentially has important repercussions for cultural transmission where social learning strategies are used. Assessing variation in efficiency is key to understanding the evolution of complex behavioural traits in primates. Here we examine evidence for individual-level differences beyond age- and sex-class in non-human primate extractive foraging efficiency.

Nonadjacent dependencies and sequential structure of chimpanzee action during a natural tool-use task.

Many of the complex behaviours of humans involve the production of nonadjacent dependencies between sequence elements, which in part can be generated through the hierarchical organization of sequences. To understand how these structural properties of human behaviours evolved, we can gain valuable insight from studying the sequential behaviours of nonhuman animals. Among the behaviours of nonhuman apes, tool use has been hypothesised to be a domain of behaviour which likely involves hierarchical organization, and may therefore possess nonadjacent dependencies between sequential actions.

Retraction: Short polyethylene glycol chains densely bound to soft nanotube channels for inhibition of protein aggregation.

[This retracts the article DOI: 10.1039/C6RA06793J.].