title: Travel fosters tool use in wild chimpanzees.
abstract: Ecological variation influences the appearance and maintenance of tool use in animals, either due to necessity or opportunity, but little is known about the relative importance of these two factors. Here, we combined long-term behavioural data on feeding and travelling with six years of field experiments in a wild chimpanzee community. In the experiments, subjects engaged with natural logs, which contained energetically valuable honey that was only accessible through tool use. Engagement with the experiment was highest after periods of low fruit availability involving more travel between food patches, while instances of actual tool-using were significantly influenced by prior travel effort only. Additionally, combining data from the main chimpanzee study communities across Africa supported this result, insofar as groups with larger travel efforts had larger tool repertoires. Travel thus appears to foster tool use in wild chimpanzees and may also have been a driving force in early hominin technological evolution.
authors.affiliation: Department of Comparative Cognition, University of Neuchâtel, Neuchâtel, Switzerland.|Budongo Conservation Field Station, Masindi, Uganda.|Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland.
authors.forename: Thibaud
authors.identifier: 0000-0002-6766-3947
authors.initials: T
authors.lastname: Gruber
authors.affiliation: Department of Comparative Cognition, University of Neuchâtel, Neuchâtel, Switzerland.|Budongo Conservation Field Station, Masindi, Uganda.|School of Psychology and Neuroscience, University of St Andrews, St Andrews, United Kingdom.
authors.forename: Klaus
authors.initials: K
authors.lastname: Zuberbühler
authors.affiliation: Department of Comparative Cognition, University of Neuchâtel, Neuchâtel, Switzerland.
authors.forename: Christof
authors.identifier: 0000-0002-0236-1219
authors.initials: C
authors.lastname: Neumann
mesh_terms: D000349:Africa; D000818:Animals; D001522:Behavior, Animal; D004781:Environmental Exposure; D005247:Feeding Behavior; D002679:Pan troglodytes; D014195:Travel
keywords: chimpanzee; ecology; tool use; travel costs