Book contents
- The Chimpanzees of the Taï Forest
- The Chimpanzees of the Taï Forest
- Copyright page
- Dedication
- Contents
- Contributors
- Preface
- Acknowledgements
- 1 War and peace in the Taï chimpanzee forest: running a long-term chimpanzee research project
- 2 Developments in statistical methods applied over four decades of research in the Taï Chimpanzee Project
- 3 Observation protocol and long-term data collection in Taï
- 4 The Wild Chimpanzee Foundation (WCF) and the Taï Chimpanzee Project (TCP)
- 5 Insights from genetic analyses of the Taï chimpanzees
- 6 Endocrinological analyses at Taï
- 7 Chimpanzee behavioural diversity and the contribution of the Taï Chimpanzee Project
- 8 An energetic model of foraging optimization: wild chimpanzee hammer selection for nut-cracking
- 9 Demography and life history of five chimpanzee communities in Taï National Park
- 10 Adoption in the Taï chimpanzees: costs, benefits and strong social relationships
- 11 Spatial integration of unusually high numbers of immigrant females into the South Group: further support for the bisexually bonded model in Taï chimpanzees
- 12 Forty years striving to capture culture among the Taï chimpanzees
- 13 Cultural diversity of nut-cracking behaviour between two populations of wild chimpanzees (Pan troglodytes verus) in the Côte d’Ivoire
- 14 Ecological and social influences on rates of social play in immature wild chimpanzees (Pan troglodytes verus)
- 15 Long-term diet of the chimpanzees (Pan troglodytes verus) in Taï National Park: interannual variations in consumption
- 16 Why Taï mangabeys do not use tools to crack nuts like sympatric-living chimpanzees: a cognitive limitation on monkey feeding ecology
- 17 Providing research for conservation from long-term field sites
- 18 Rank changes in female chimpanzees in Taï National Park
- 19 Effects of large-scale knockouts on chimpanzee association networks
- 20 Why do the chimpanzees of the Taï Forest share meat? The value of bartering, begging and hunting
- 21 Group-specific social dynamics affect urinary oxytocin levels in Taï male chimpanzees
- 22 The chimpanzees of the Taï Forest as models for hominine microorganism ecology and evolution
- 23 Acute infectious diseases occurring in the Taï chimpanzee population: a review
- 24 Why does the chimpanzee vocal repertoire remain poorly understood and what can be done about it?
- 25 Evidence for sexual dimorphism in chimpanzee vocalizations: a comparison of male and female call production and acoustic parameters
- 26 Gestural usage and development in two chimpanzee groups of different subspecies (Pan troglodytes verus/P.t. schweinfurthii)
- 27 Spatial cognitive abilities in foraging chimpanzees
- 28 Temporal cognition in Taï chimpanzees
- Index
- References
8 - An energetic model of foraging optimization: wild chimpanzee hammer selection for nut-cracking
Published online by Cambridge University Press: 25 November 2019
- The Chimpanzees of the Taï Forest
- The Chimpanzees of the Taï Forest
- Copyright page
- Dedication
- Contents
- Contributors
- Preface
- Acknowledgements
- 1 War and peace in the Taï chimpanzee forest: running a long-term chimpanzee research project
- 2 Developments in statistical methods applied over four decades of research in the Taï Chimpanzee Project
- 3 Observation protocol and long-term data collection in Taï
- 4 The Wild Chimpanzee Foundation (WCF) and the Taï Chimpanzee Project (TCP)
- 5 Insights from genetic analyses of the Taï chimpanzees
- 6 Endocrinological analyses at Taï
- 7 Chimpanzee behavioural diversity and the contribution of the Taï Chimpanzee Project
- 8 An energetic model of foraging optimization: wild chimpanzee hammer selection for nut-cracking
- 9 Demography and life history of five chimpanzee communities in Taï National Park
- 10 Adoption in the Taï chimpanzees: costs, benefits and strong social relationships
- 11 Spatial integration of unusually high numbers of immigrant females into the South Group: further support for the bisexually bonded model in Taï chimpanzees
- 12 Forty years striving to capture culture among the Taï chimpanzees
- 13 Cultural diversity of nut-cracking behaviour between two populations of wild chimpanzees (Pan troglodytes verus) in the Côte d’Ivoire
- 14 Ecological and social influences on rates of social play in immature wild chimpanzees (Pan troglodytes verus)
- 15 Long-term diet of the chimpanzees (Pan troglodytes verus) in Taï National Park: interannual variations in consumption
- 16 Why Taï mangabeys do not use tools to crack nuts like sympatric-living chimpanzees: a cognitive limitation on monkey feeding ecology
- 17 Providing research for conservation from long-term field sites
- 18 Rank changes in female chimpanzees in Taï National Park
- 19 Effects of large-scale knockouts on chimpanzee association networks
- 20 Why do the chimpanzees of the Taï Forest share meat? The value of bartering, begging and hunting
- 21 Group-specific social dynamics affect urinary oxytocin levels in Taï male chimpanzees
- 22 The chimpanzees of the Taï Forest as models for hominine microorganism ecology and evolution
- 23 Acute infectious diseases occurring in the Taï chimpanzee population: a review
- 24 Why does the chimpanzee vocal repertoire remain poorly understood and what can be done about it?
- 25 Evidence for sexual dimorphism in chimpanzee vocalizations: a comparison of male and female call production and acoustic parameters
- 26 Gestural usage and development in two chimpanzee groups of different subspecies (Pan troglodytes verus/P.t. schweinfurthii)
- 27 Spatial cognitive abilities in foraging chimpanzees
- 28 Temporal cognition in Taï chimpanzees
- Index
- References
Summary
The chimpanzees of the Taï Forest, Côte d’Ivoire, crack highly nutritious Coula edulis nuts using anvils and hammers. While using tools to access encased food items provides obvious benefits, the energetic gain of tool-assisted foraging can be further increased by optimal selection of tools. Previous studies of animal tool selection often relied on implicit assumptions or theoretical arguments about how tool features would influence foraging efficiency, and comprehensive measures of actual efficiency are still missing. We used field observations of nut-cracking efficiency and previously published estimates of energetic costs to investigate the rate of net energy intake as a function of hammer weight and hammer material. While stones allowed for a generally more efficient performance, nut-cracking efficiency depended on an interaction of hammer weight and material. Relative performance of stones and wood varied according to the ripeness of the nuts. Chimpanzees’ tool selection tends to optimize nut-cracking in many respects. Nonetheless, we also observed a few mismatches between efficiency and selection, some of which may be explained on cognitive, motivational or cultural grounds.
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- The Chimpanzees of the Taï Forest40 Years of Research, pp. 104 - 124Publisher: Cambridge University PressPrint publication year: 2019