Fruits of Enlightenment: Foraging Cognition in large-brained Rainforest Primates

Karline R. L. Janmaat

Department of Primatology, Max Planck Institute for Evolutionary Anthropology

Despite appealing support for theories that argue that social complexity is the main force driving primate brain size evolution, it is still unclear how great apes, were able to afford the evolution of larger and more expensive brains than sympatric species (Byrne 1997). Recent studies suggest that the costs of evolutionary brain enlargement were overcome by a permanent increase in net energy intake, renewing interest in the role of ecological complexity in primate brain size evolution (Navarrete et al 2011). As relatively larger-brained primates, like great apes, show less seasonality in their net energy intake than smaller-brained species, larger brains are proposed to provide a “cognitive behavioral flexibility” that facilitates the consumption of nutritious foods during food scarce periods (cognitive buffer hypothesis; van Woerden et al. 2012).  To date it remains unclear what this cognitive flexibility entails. In this presentation I will provide evidence for a variety of cognitive skills that larger-brained non-human primates can use to gain first access to newly ripened energy-rich fruit in a competitive and complex rain forest environment.

Recent publications:

Janmaat, K., Polansky, L., Ban, S. D., & Boesch, C. (2014). Wild chimpanzees plan their breakfast time, type, and location. Proceedings of the National Academy of Sciences of the United States of America, 111(46), 16343-16348.

Janmaat, K. R. L., Ban, S. D., & Boesch, C. (2013). Taï chimpanzees use botanical skills to discover fruit: What we can learn from their mistakes. Animal Cognition, 16(6), 851-860.

Janmaat, K., Ban, S. D., & Boesch, C. (2013). Chimpanzees use long-term spatial memory to monitor large fruit trees and remember feeding experiences across seasons. Animal Behaviour, 86(6), 1183-1205.