Geraldine Ischer

Research Interest

Chimpanzee communication: understanding food calls and greeting calls of the Sonso community at Budongo, Uganda

Previous research has reported that chimpanzees produce different types of grunts during social interactions, notably ‘pant grunts’ when encountering other group members (greeting calls) and ‘rough grunts’ when finding food (food calls). A number of studies have argued that rough grunts supposedly function to inform the others about the presence of food. However, this interpretation has been challenged, also because food calls and greeting calls are acoustically very similar and are both elicited by the presence of higher-ranking group members.

In this study, I would like to test the hypothesis that chimpanzees use food calls, not to inform others about the presence of food, but as a signal of submission to avoid agonistic interactions with more competitive individuals. For this purpose, I will compare food calls and greeting calls in terms of their acoustic structure and patterns of calling.

The Budongo Conservation Field station is a well-known location for research and conservation work on chimpanzees and other species.

My main goal is to test the possibility that food call production is the result of a more egoistic than altruistic motivation and try to understand why chimpanzees alert others when in the presence of food. This study will give further information on how social factors influence daily behaviours and also contribute to the extensive study of flexible vocalisation in chimpanzees.