14 research outputs found
Food cleaning in gorillas: Social learning is a possibility but not a necessity
Food cleaning is widespread in the animal kingdom, and a recent report confirmed that (amongst other behaviours) wild western lowland gorillas also show food cleaning. The authors of this report conclude that this behaviour, based on its distribution patterns, constitutes a potential candidate for culture. While different conceptualisations of culture exist, some more and some less reliant on behavioural form copying, all of them assign a special role to social learning processes in explaining potentially cultural behaviours. Here we report the results of an experiment that tested to what extent food cleaning behaviour in a group of captive Western lowland gorillas (Gorilla gorilla gorilla) relies on social learning processes. Subjects were provided with clean and dirty apples. When they were provided with dirty apples, all subjects showed evidence of food cleaning in at least 75% of trials. Preferred cleaning techniques differed between individuals, four out of five of subjects expressed a behaviour analogous to that reported in wild conspecifics. Given this occurrence of food cleaning in a culturally unconnected population of gorillas, we conclude that social learning is unlikely to play a central role in the emergence of the food cleaning behavioural form in Western lowland gorillas; instead, placing a greater emphasis on individual learning of food cleaning’s behavioural form
Intentional communication between wild bonnet macaques and humans
Comparative studies of nonhuman communication systems could provide insights into the origins and
evolution of a distinct dimension of human language: intentionality. Recent studies have provided
evidence for intentional communication in diferent species but generally in captive settings. We report
here a novel behaviour of food requesting from humans displayed by wild bonnet macaques Macaca
radiata, an Old World cercopithecine primate, in the Bandipur National Park of southern India. Using
both natural observations and feld experiments, we examined four diferent behavioural components—
coo-calls, hand-extension gesture, orientation, and monitoring behaviour—of food requesting for their
conformity with the established criteria of intentional communication. Our results suggest that food
requesting by bonnet macaques is potentially an intentionally produced behavioural strategy as all
the food requesting behaviours except coo-calls qualify the criteria for intentionality. We comment on
plausible hypotheses for the origin and spread of this novel behavioural strategy in the study macaque
population and speculate that the cognitive precursors for language production may be manifest in the
usage of combination of signals of diferent modalities in communication, which could have emerged in
simians earlier than in the anthropoid ape