Do chimpanzee food calls bias listeners toward novel items?

Social learning is beneficial in almost every domain of a social animal's life, but it is particularly important in the context of predation and foraging. In both contexts, social animals tend to produce acoustically distinct vocalizations, alarms, and food calls, which have remained somewhat of an evolutionary conundrum as they appear to be costly for the signaller. Here, we investigated the hypothesis that food calls function to direct others toward novel food items, using a playback experiment on a group of chimpanzees.

Food calls enhance visual discrimination learning in chimpanzees (Pan troglodytes verus).

Social learning is of universal importance to animal life, and communication is likely to foster it. How do animals recognize when others produce actions that lead to relevant new information? To address this, we exposed 4 chimpanzees to an arbitrary learning task, a 2-choice visual discrimination paradigm presented on a touch screen that led to food reward. In each trial, images were paired with 1 of 4 acoustic treatments: (a) relevant or (b) irrelevant chimpanzee calls ("rough grunts" to food; "pant grunts" to a dominant conspecific), (c) a mechanical noise (hammer knocking sounds) and (d) silence.

Humans and Chimpanzees Display Opposite Patterns of Diversity in Genes.

Among the many genes involved in the metabolism of therapeutic drugs, human arylamine -acetyltransferases () genes have been extensively studied, due to their medical importance both in pharmacogenetics and disease epidemiology. One member of this small gene family, , is established as the locus of the classic human acetylation polymorphism in drug metabolism. Current hypotheses hold that selective processes favoring haplotypes conferring lower activity have been operating in modern humans' recent history as an adaptation to local chemical and dietary environments.