Final Report Summary - CHIMPCULT (Testing the cultural hypothesis in wild chimpanzees through the use of tool use and playback field experiments)
- Summary description of the project objectives
The objectives of this project were three-folded. The applicant was to develop his research skills, by implementing a combination of novel field experiments in Uganda; to develop his academic skills by acquiring teaching and supervising experience at the University of Neuchâtel; and to develop his leadership skills and independence by creating a novel field site station in Uganda.
The general aim of this project was to develop methods to study experimentally culture in wild chimpanzees and understand how behavioural variation in chimpanzees relates to human cultures. The research objectives aimed at extending and complementing the honey-trap experiments, a field experiment originally designed by the applicant during his PhD, where chimpanzees must recover inaccessible honey from a hole drilled into a natural log (Figure 1). To do so, the applicant aimed to rely on this experiment to seed a novel behaviour in the Sonso chimpanzee community of Budongo Forest, Uganda, stick use, and study its spread through the community. The honey-trap experiment was first used to analyse the cultural knowledge of wild chimpanzees. Another aspect to be explored during this fellowship was to expand it to other communities in the vicinity of the Budongo Forest to study their cultural knowledge. Another research objective was to develop novel techniques to study the cognitive bases of culture in chimpanzee. For instance, because the honey-trap experiment originally led chimpanzees to use techniques already present in their normal repertoire (e.g. leaf-sponges), it could be argued that there was nothing cultural about them. Therefore, this second objective aimed to address this point, by designing a new methodology to study novel behaviours in the community. Finally, a third research objective was to expend the study of culture from the physical to the social world, by studying in details some low-pitched vocalisations, named ‘hoos’, and their use in the community, through observational and experimental techniques. In particular, the use of ‘resting’ and ‘travel’ hoos was to be studied systematically, to offer potential inter-site comparisons.
The training objectives at the University of Neuchâtel involved two aspects for the applicant. First, he was to acquire new knowledge of particular softwares used in vocal communication to develop his analytical skills. Second, he was to take over teaching and supervision duties in order to specifically enhance this aspect of his curriculum, which had not been particularly developed during his PhD. To this effect, the applicant was to assist his host in teaching, as well as develop his own lectures. Finally, the applicant was to take several master students and help co-supervise PhD students. The final training objective was to establish a field site in Uganda. This involved to make contact with local authorities and to start a project, beginning with hiring local staff and starting surveys to localise chimpanzee communities in a forest that had not been subjected to research so far.
- Description of the work performed since the beginning of the project
Over the course of two field seasons spread between 2014 and 2015, the applicant has conducted a total of 75 experimental trials with the Sonso community (18 individuals tested, average number of trials/per individual: 4.2 range: 1-13), which has led two individuals to display stick use during one experimental trial (Figure 1). Ecological surveys have also been conducted in the neighbouring communities of Sonso: the Kamira community (North-West) and the Waibira community (North-East). The work has aimed to document the ecological differences between the Sonso core area and the other communities’ core areas to determine whether the absence of stick use in Sonso may result from the environmental settings. Some experimental work was conducted in Kamira but no chimpanzee was willing to engage with the honey-trap apparatus. In Sonso, the applicant has also developed a field protocol to study the hoo vocalisations of chimpanzees and implemented several field experiments in collaboration with other researchers at the Budongo Conservation Field Station. The honey-trap experiments have also been conducted in a satellite forest of Budongo, the Bulindi Forest, where observational data have confirmed the presence of stick use. During the second year of the project, the work efforts have been focussed on the Bugoma Forest, where the applicant has started the habituation of a chimpanzee community, a major project for the future of his academic career.
At Neuchâtel, the applicant has been actively engaged in teaching and has participated to the teaching of several classes (Physiology, Statistics, Scientific Writing). The applicant has also taken five master students in supervision, two in the field, two at the Basel Zoo and one conducting work with children in collaboration with the Humanities Faculty at the University of Neuchâtel. Additionally, the applicant has developed collaboration with the Basel Zoo to study its captive ape populations.
- Description of the main results achieved
By the end of the field work, two chimpanzees have used a stick or a twig in the experiment, independently from each other, showing that the honey-trap experiment is a valid protocol to seed a novel behaviour in a wild chimpanzee community. However, none of the two individuals has displayed the behaviour again in subsequent trials and the stick use behaviour has not been seeded in the Sonso community so far. Nevertheless individuals from the younger generation (<10 years old) have displayed interest in the experiment and the stick, suggesting that more exposures will eventually lead to additional stick use trials from the chimpanzees, and the potential spread of the behaviour. Over the course of the two years, the applicant has also engaged in two modelling analyses of the tool use data collected in Sonso to contribute data to the current debate on chimpanzee culture. One analysis aimed to model the spread of a novel behaviour, moss-sponging, in the Sonso community and found evidence of social learning for the diffusion of this behaviour. The second modelling analysis aimed to analyse how ecological parameters can predict tool use in wild chimpanzees. This analysis showed that chimpanzees were more likely to engage in the experiment when they had experienced ecological stress. Finally, the applicant has summarised the theoretical implications of his findings in an open-access article aiming to isolate the main differences between chimpanzees and humans.
- Expected final results and their potential impact
These results are likely to have an important impact on current research in the field of primatology and human evolution. For instance, the first modelling study published Open Access in the top tier journal PLOS Biology has contributed to advance the debate significantly and got much media coverage outside of academia. The second modelling study may also have an important impact on the field. The results found are in line with the theoretical insights developed by the applicant and his colleagues, suggesting new ways to address the question of the uniqueness of humans among primates.
From an academic point of view, this fellowship has brought the applicant closer to full independency. During this project, the applicant has successfully managed his own team, consisting of Master students and field assistants. During the second year of the project, the Bugoma Conservation and Research Project (BCRP) was officially launched. The applicant has therefore reached his goal of developing a field site and starting a new habituation project, which will allow him to reach full independency by the time the chimpanzees are fully habituated. The applicant has also developed his network in the ERA, where he has been invited to give talks to present his research. This was also the occasion to launch new collaborative projects. Finally, the applicant has been awarded a grant from the Swiss National Science Foundation to continue his work at the University of Geneva.
The objectives of this project were three-folded. The applicant was to develop his research skills, by implementing a combination of novel field experiments in Uganda; to develop his academic skills by acquiring teaching and supervising experience at the University of Neuchâtel; and to develop his leadership skills and independence by creating a novel field site station in Uganda.
The general aim of this project was to develop methods to study experimentally culture in wild chimpanzees and understand how behavioural variation in chimpanzees relates to human cultures. The research objectives aimed at extending and complementing the honey-trap experiments, a field experiment originally designed by the applicant during his PhD, where chimpanzees must recover inaccessible honey from a hole drilled into a natural log (Figure 1). To do so, the applicant aimed to rely on this experiment to seed a novel behaviour in the Sonso chimpanzee community of Budongo Forest, Uganda, stick use, and study its spread through the community. The honey-trap experiment was first used to analyse the cultural knowledge of wild chimpanzees. Another aspect to be explored during this fellowship was to expand it to other communities in the vicinity of the Budongo Forest to study their cultural knowledge. Another research objective was to develop novel techniques to study the cognitive bases of culture in chimpanzee. For instance, because the honey-trap experiment originally led chimpanzees to use techniques already present in their normal repertoire (e.g. leaf-sponges), it could be argued that there was nothing cultural about them. Therefore, this second objective aimed to address this point, by designing a new methodology to study novel behaviours in the community. Finally, a third research objective was to expend the study of culture from the physical to the social world, by studying in details some low-pitched vocalisations, named ‘hoos’, and their use in the community, through observational and experimental techniques. In particular, the use of ‘resting’ and ‘travel’ hoos was to be studied systematically, to offer potential inter-site comparisons.
The training objectives at the University of Neuchâtel involved two aspects for the applicant. First, he was to acquire new knowledge of particular softwares used in vocal communication to develop his analytical skills. Second, he was to take over teaching and supervision duties in order to specifically enhance this aspect of his curriculum, which had not been particularly developed during his PhD. To this effect, the applicant was to assist his host in teaching, as well as develop his own lectures. Finally, the applicant was to take several master students and help co-supervise PhD students. The final training objective was to establish a field site in Uganda. This involved to make contact with local authorities and to start a project, beginning with hiring local staff and starting surveys to localise chimpanzee communities in a forest that had not been subjected to research so far.
- Description of the work performed since the beginning of the project
Over the course of two field seasons spread between 2014 and 2015, the applicant has conducted a total of 75 experimental trials with the Sonso community (18 individuals tested, average number of trials/per individual: 4.2 range: 1-13), which has led two individuals to display stick use during one experimental trial (Figure 1). Ecological surveys have also been conducted in the neighbouring communities of Sonso: the Kamira community (North-West) and the Waibira community (North-East). The work has aimed to document the ecological differences between the Sonso core area and the other communities’ core areas to determine whether the absence of stick use in Sonso may result from the environmental settings. Some experimental work was conducted in Kamira but no chimpanzee was willing to engage with the honey-trap apparatus. In Sonso, the applicant has also developed a field protocol to study the hoo vocalisations of chimpanzees and implemented several field experiments in collaboration with other researchers at the Budongo Conservation Field Station. The honey-trap experiments have also been conducted in a satellite forest of Budongo, the Bulindi Forest, where observational data have confirmed the presence of stick use. During the second year of the project, the work efforts have been focussed on the Bugoma Forest, where the applicant has started the habituation of a chimpanzee community, a major project for the future of his academic career.
At Neuchâtel, the applicant has been actively engaged in teaching and has participated to the teaching of several classes (Physiology, Statistics, Scientific Writing). The applicant has also taken five master students in supervision, two in the field, two at the Basel Zoo and one conducting work with children in collaboration with the Humanities Faculty at the University of Neuchâtel. Additionally, the applicant has developed collaboration with the Basel Zoo to study its captive ape populations.
- Description of the main results achieved
By the end of the field work, two chimpanzees have used a stick or a twig in the experiment, independently from each other, showing that the honey-trap experiment is a valid protocol to seed a novel behaviour in a wild chimpanzee community. However, none of the two individuals has displayed the behaviour again in subsequent trials and the stick use behaviour has not been seeded in the Sonso community so far. Nevertheless individuals from the younger generation (<10 years old) have displayed interest in the experiment and the stick, suggesting that more exposures will eventually lead to additional stick use trials from the chimpanzees, and the potential spread of the behaviour. Over the course of the two years, the applicant has also engaged in two modelling analyses of the tool use data collected in Sonso to contribute data to the current debate on chimpanzee culture. One analysis aimed to model the spread of a novel behaviour, moss-sponging, in the Sonso community and found evidence of social learning for the diffusion of this behaviour. The second modelling analysis aimed to analyse how ecological parameters can predict tool use in wild chimpanzees. This analysis showed that chimpanzees were more likely to engage in the experiment when they had experienced ecological stress. Finally, the applicant has summarised the theoretical implications of his findings in an open-access article aiming to isolate the main differences between chimpanzees and humans.
- Expected final results and their potential impact
These results are likely to have an important impact on current research in the field of primatology and human evolution. For instance, the first modelling study published Open Access in the top tier journal PLOS Biology has contributed to advance the debate significantly and got much media coverage outside of academia. The second modelling study may also have an important impact on the field. The results found are in line with the theoretical insights developed by the applicant and his colleagues, suggesting new ways to address the question of the uniqueness of humans among primates.
From an academic point of view, this fellowship has brought the applicant closer to full independency. During this project, the applicant has successfully managed his own team, consisting of Master students and field assistants. During the second year of the project, the Bugoma Conservation and Research Project (BCRP) was officially launched. The applicant has therefore reached his goal of developing a field site and starting a new habituation project, which will allow him to reach full independency by the time the chimpanzees are fully habituated. The applicant has also developed his network in the ERA, where he has been invited to give talks to present his research. This was also the occasion to launch new collaborative projects. Finally, the applicant has been awarded a grant from the Swiss National Science Foundation to continue his work at the University of Geneva.