We empirically tested Hemelrijk's agent-based model, in which dyadic agonistic interaction between primate-group subjects determines their spatial distribution and whether or not the dominant subject has a central position with respect to the other subjects. We studied a group of captive red-capped mangabeys that met the optimal conditions for testing this model. We analyzed the spatial distribution of the subjects in relation to their rank in the dominance hierarchy and the results confirmed the validity of this model. In accordance with (...) Hemelrijk's model, the group studied showed an ambiguity-reducing strategy that led to non-central spatial positioning on the part of the dominant subject, thus confirming the model indirectly. Nevertheless, for the model to be confirmed directly, the group has to adopt a risk-sensitive strategy so that observers can study whether dominant subjects develop spatial centrality. Our study also demonstrated that agent-based models are a good tool for the study of certain complex behaviors observed in primates because these explanatory models can help formulate suggestive hypotheses for exploring new lines of research in primatology. Keywords: Dominance-hierarchy rank; spatial distribution; Cercocebus torquatus ; agent-based models. (shrink)

We empirically tested Hemelrijk’s agent-based model, in which dyadic agonistic interaction between primate-group subjects determines their spatial distribution and whether or not the dominant subject has a central position with respect to the other subjects. We studied a group of captive red-capped mangabeys that met the optimal conditions for testing this model. We analyzed the spatial distribution of the subjects in relation to their rank in the dominance hierarchy and the results confirmed the validity of this model. In accordance with (...) Hemelrijk’s model, the group studied showed an ambiguity-reducing strategy that led to non-central spatial positioning on the part of the dominant subject, thus confirming the model indirectly. Nevertheless, for the model to be confirmed directly, the group has to adopt a risk-sensitive strategy so that observers can study whether dominant subjects develop spatial centrality. Our study also demonstrated that agent-based models are a good tool for the study of certain complex behaviors observed in primates because these explanatory models can help formulate suggestive hypotheses for exploring new lines of research in primatology. Keywords: Dominance-hierarchy rank; spatial distribution;Cercocebus torquatus; agent-based models. (shrink)

We empirically tested Hemelrijk’s agent-based model, in which dyadic agonistic interaction between primate-group subjects determines their spatial distribution and whether or not the dominant subject has a central position with respect to the other subjects. We studied a group of captive red-capped mangabeys that met the optimal conditions for testing this model. We analyzed the spatial distribution of the subjects in relation to their rank in the dominance hierarchy and the results confirmed the validity of this model. In accordance with (...) Hemelrijk’s model, the group studied showed an ambiguity-reducing strategy that led to non-central spatial positioning on the part of the dominant subject, thus confirming the model indirectly. Nevertheless, for the model to be confirmed directly, the group has to adopt a risk-sensitive strategy so that observers can study whether dominant subjects develop spatial centrality. Our study also demonstrated that agent-based models are a good tool for the study of certain complex behaviors observed in primates because these explanatory models can help formulate suggestive hypotheses for exploring new lines of research in primatology. Keywords: Dominance-hierarchy rank; spatial distribution; Cercocebus torquatus; agent-based models. (shrink)

Taking a detour to reach a goal is intelligent behavior based on making inferences. The main purpose of the present research is to show how such apparently complex behavior can emerge from basic mechanisms such as contextual categorisation and goal attribution when perceiving people. We presentacacia (Action by Contextually Automated Categorising Interactive Agents), a computer model implemented using StarLogo software, grounded in the principles of Artificial Life (Al), capable of simulating the behavior of a group of agents with a goal (...) (for instance, to find a treasure in a treasure hunt ) in an environment where obstacles mask the goal site. The results of the simulations show that agents reach the goal the fastest when they follow each other and take detours. We argue that these results indicate that intelligent adaptive behavior is based on the contextual categorisation of environmental constrainst (that is, obstacles and other agents). (shrink)

Individuals’ spatial position is affected by social factors. The majority of studies correlating spatial position and social factors have used methods with drawbacks. A more complete method was developed by Dolado & Beltran (2011) in captive animals. The present study aimed to apply a modified version of this method in two semi-free-ranging macaque groups. The proposed method divides group’s surroundings into different subareas, selecting different points in each subarea and calculating the coordinates of these points. We filmed each group and (...) analyzed the videos using an activated time transition recording to determine the individuals’ coordinates. With these data, we calculated spatial variables, allowing us to obtain groups’ spatial patterns. The current method improves on previous procedures and could be applied to larger study areas and groups than the method of Dolado & Beltran (2011), thus representing a viable option for studying spatial distribution patterns in semi-free-ranging macaque groups. (shrink)