Sequential organization, development, and senescence of stone-tool use across wild chimpanzee lifetimes
<p>Many behaviours of animals are comprised of individual units (such as actions, calls, or gestures), which are performed over space and time. These sequential behaviours can span vast temporospatial scales, and include the fast-paced movements of a fly’s limbs when grooming its body, as well...
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| Drugi avtorji: | |
| Format: | Thesis |
| Jezik: | English |
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2023
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| Teme: |
| _version_ | 1826313436215115776 |
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| author | Howard-Spink, E |
| author2 | Biro, D |
| author_facet | Biro, D Howard-Spink, E |
| author_sort | Howard-Spink, E |
| collection | OXFORD |
| description | <p>Many behaviours of animals are comprised of individual units (such as actions, calls, or gestures), which are performed over space and time. These sequential behaviours can span vast temporospatial scales, and include the fast-paced movements of a fly’s limbs when grooming its body, as well as the vast migrations of elephants with the turnover of seasons. To produce a sequential behaviour, animals are faced with making an extended number of decisions surrounding which behavioural units to elicit in relation to all others in the sequence. Thus, understanding how animals organize sequential behaviours offers a unique and valuable window into understanding their cognitive processes. Research into the organization of sequential behaviours often focuses on those which are considered to be in some way ‘complex’; such as the highly flexible combinations of notes in birdsong, or the elaborate sequences of actions performed by humans during the production and use of highly technical tools. Among animals, humans are believed to possess a suite of particularly complex sequential behaviours, including language; musical abilities; and as mentioned, tool production and use. Nonhuman animal (henceforth animal) models serve as valuable systems for understanding the environmental contexts that select for the evolution of complexity within specific sequential behaviours; and of all animals, nonhuman primates (henceforth primates) offer a unique model for understanding the evolution of human behaviours, especially great-apes, given the likely homologous origins of behavioural similarities with humans. Thus, how great-apes organize, acquire, and retain sequential behaviours throughout their lives is a key question for understanding their cognition, and the evolutionary processes that shaped our own.</p>
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<p>This thesis explores how wild West-African chimpanzees (Pan troglodytes verus) organize their actions during one of their most complex tool-use behaviours: the cracking of hard-shelled nuts using hammer and anvil stones (nut cracking). The data for this thesis are collected from a small population of chimpanzees living in the forests surrounding the village of Bossou, Guinea. The chimpanzees at Bossou have been studied for many decades, and perform a wide range of tool-use behaviours. Of these tool-use behaviours, nut cracking has been studied for over 30 years at Bossou through the use of an outdoor laboratory: a natural clearing in the forest where researchers deposit piles of nuts, and a selection of stone tools. Chimpanzees are free to visit the outdoor lab as part of their daily ranging behaviours, and when present, spontaneously engage in nut cracking, which is recorded by researchers using video cameras. Following the decades of data collection at Bossou, videos of chimpanzees engaging in nut cracking at the outdoor laboratory have been organized into a longitudinal video archive (the Bossou Archive). This data-rich video archive presents a unique opportunity to characterize the sequential behaviours of chimpanzees during tool-use, and allows for the behaviours of individual chimpanzees to be studied longitudinally, across extended periods of their lives.</p>
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<p>This thesis interrogates three key questions: how do chimpanzees organize actions during their stone tool- use behaviours? How do chimpanzees acquire the repertoire of actions which allows for efficient stone-tool use? And finally, how do stone-tool use behaviours of chimpanzees change as they experience progressive old-age? In chapter 2, I coded over 8000 individual actions performed by chimpanzees during nut cracking, and draw upon the mutual information (MI) between actions in sequences to evidence that chimpanzees most likely structure sequences of actions hierarchically during tool-use behaviours, and produce nonadjacent dependencies between elements (a key property of human sequential action and language). In chapter 3, I developed upon this finding by programming a bespoke dictionary-based compression algorithm, which identified a number of candidate subroutines (shorter subsequences of actions) which are likely associated with this hierarchical organization. In chapter 4, I investigated how the repertoires of actions used by chimpanzees develops between one and eight years of age, and compared this developmental trajectory with the behaviours of adults, using over 24,000 coded actions. This chapter suggests that chimpanzees first explore many possible solutions to nut cracking, and once the skill is successfully acquired, refine their strategies across many years through pruning the action repertoire. In chapter 5, I investigated how the nut cracking behaviours of wild chimpanzees change as they experience progressive old-age, and report that tool-use behaviours of chimpanzees are subject to senescence, but, much like in humans, the extent and rate of senescence varies between individuals.</p>
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<p>Ultimately, this thesis describes the structure of nut cracking behaviours of wild chimpanzees at an exceptional granularity, and traces how these behaviours change across individual lifetimes. Additionally, this thesis employs a number of highly computational methods for the study of sequential organization in animals, and provides several methodological considerations for further research in this field. The results of this thesis directly feed into a number of existing hypotheses surrounding the evolution of complex behaviours of humans, including early hominin stone-tool use; linguistic syntax, as well as processes of social learning, and the evolution of human culture.</p> |
| first_indexed | 2024-09-25T04:12:59Z |
| format | Thesis |
| id | oxford-uuid:f031dbd2-d7c6-431d-87b8-4ab94ab10b49 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-09-25T04:12:59Z |
| publishDate | 2023 |
| record_format | dspace |
| spelling | oxford-uuid:f031dbd2-d7c6-431d-87b8-4ab94ab10b492024-07-04T15:00:36ZSequential organization, development, and senescence of stone-tool use across wild chimpanzee lifetimesThesishttp://purl.org/coar/resource_type/c_db06uuid:f031dbd2-d7c6-431d-87b8-4ab94ab10b49Tool use in animalsHuman evolutionAnimal cultureChimpanzeesAnimal behaviorEnglishHyrax Deposit2023Howard-Spink, EBiro, DGruber, TGuilford, TTownsend, S<p>Many behaviours of animals are comprised of individual units (such as actions, calls, or gestures), which are performed over space and time. These sequential behaviours can span vast temporospatial scales, and include the fast-paced movements of a fly’s limbs when grooming its body, as well as the vast migrations of elephants with the turnover of seasons. To produce a sequential behaviour, animals are faced with making an extended number of decisions surrounding which behavioural units to elicit in relation to all others in the sequence. Thus, understanding how animals organize sequential behaviours offers a unique and valuable window into understanding their cognitive processes. Research into the organization of sequential behaviours often focuses on those which are considered to be in some way ‘complex’; such as the highly flexible combinations of notes in birdsong, or the elaborate sequences of actions performed by humans during the production and use of highly technical tools. Among animals, humans are believed to possess a suite of particularly complex sequential behaviours, including language; musical abilities; and as mentioned, tool production and use. Nonhuman animal (henceforth animal) models serve as valuable systems for understanding the environmental contexts that select for the evolution of complexity within specific sequential behaviours; and of all animals, nonhuman primates (henceforth primates) offer a unique model for understanding the evolution of human behaviours, especially great-apes, given the likely homologous origins of behavioural similarities with humans. Thus, how great-apes organize, acquire, and retain sequential behaviours throughout their lives is a key question for understanding their cognition, and the evolutionary processes that shaped our own.</p> <br> <p>This thesis explores how wild West-African chimpanzees (Pan troglodytes verus) organize their actions during one of their most complex tool-use behaviours: the cracking of hard-shelled nuts using hammer and anvil stones (nut cracking). The data for this thesis are collected from a small population of chimpanzees living in the forests surrounding the village of Bossou, Guinea. The chimpanzees at Bossou have been studied for many decades, and perform a wide range of tool-use behaviours. Of these tool-use behaviours, nut cracking has been studied for over 30 years at Bossou through the use of an outdoor laboratory: a natural clearing in the forest where researchers deposit piles of nuts, and a selection of stone tools. Chimpanzees are free to visit the outdoor lab as part of their daily ranging behaviours, and when present, spontaneously engage in nut cracking, which is recorded by researchers using video cameras. Following the decades of data collection at Bossou, videos of chimpanzees engaging in nut cracking at the outdoor laboratory have been organized into a longitudinal video archive (the Bossou Archive). This data-rich video archive presents a unique opportunity to characterize the sequential behaviours of chimpanzees during tool-use, and allows for the behaviours of individual chimpanzees to be studied longitudinally, across extended periods of their lives.</p> <br> <p>This thesis interrogates three key questions: how do chimpanzees organize actions during their stone tool- use behaviours? How do chimpanzees acquire the repertoire of actions which allows for efficient stone-tool use? And finally, how do stone-tool use behaviours of chimpanzees change as they experience progressive old-age? In chapter 2, I coded over 8000 individual actions performed by chimpanzees during nut cracking, and draw upon the mutual information (MI) between actions in sequences to evidence that chimpanzees most likely structure sequences of actions hierarchically during tool-use behaviours, and produce nonadjacent dependencies between elements (a key property of human sequential action and language). In chapter 3, I developed upon this finding by programming a bespoke dictionary-based compression algorithm, which identified a number of candidate subroutines (shorter subsequences of actions) which are likely associated with this hierarchical organization. In chapter 4, I investigated how the repertoires of actions used by chimpanzees develops between one and eight years of age, and compared this developmental trajectory with the behaviours of adults, using over 24,000 coded actions. This chapter suggests that chimpanzees first explore many possible solutions to nut cracking, and once the skill is successfully acquired, refine their strategies across many years through pruning the action repertoire. In chapter 5, I investigated how the nut cracking behaviours of wild chimpanzees change as they experience progressive old-age, and report that tool-use behaviours of chimpanzees are subject to senescence, but, much like in humans, the extent and rate of senescence varies between individuals.</p> <br> <p>Ultimately, this thesis describes the structure of nut cracking behaviours of wild chimpanzees at an exceptional granularity, and traces how these behaviours change across individual lifetimes. Additionally, this thesis employs a number of highly computational methods for the study of sequential organization in animals, and provides several methodological considerations for further research in this field. The results of this thesis directly feed into a number of existing hypotheses surrounding the evolution of complex behaviours of humans, including early hominin stone-tool use; linguistic syntax, as well as processes of social learning, and the evolution of human culture.</p> |
| spellingShingle | Tool use in animals Human evolution Animal culture Chimpanzees Animal behavior Howard-Spink, E Sequential organization, development, and senescence of stone-tool use across wild chimpanzee lifetimes |
| title | Sequential organization, development, and senescence of stone-tool use across wild chimpanzee lifetimes |
| title_full | Sequential organization, development, and senescence of stone-tool use across wild chimpanzee lifetimes |
| title_fullStr | Sequential organization, development, and senescence of stone-tool use across wild chimpanzee lifetimes |
| title_full_unstemmed | Sequential organization, development, and senescence of stone-tool use across wild chimpanzee lifetimes |
| title_short | Sequential organization, development, and senescence of stone-tool use across wild chimpanzee lifetimes |
| title_sort | sequential organization development and senescence of stone tool use across wild chimpanzee lifetimes |
| topic | Tool use in animals Human evolution Animal culture Chimpanzees Animal behavior |
| work_keys_str_mv | AT howardspinke sequentialorganizationdevelopmentandsenescenceofstonetooluseacrosswildchimpanzeelifetimes |