Biology subjects

Canteloup, C.

Publications and source records attributed to Canteloup, C..

8 recordsLinked to original sources

bioRxiv2026

Developing an accessible judgement bias task for non-human primates

Objective and efficient methods for investigating animal's mental states are important for advancing animal welfare research. Behavioural observations and physiological measures provide valuable information but may not fully capture affective states. Judgment Bias Tasks (JBTs) offer a promising method to infer affective states from animals' responses to ambiguous stimuli, as distressed individuals show more pessimistic tendencies. However, the application of JBTs outside research settings may be limited due to time-consuming training and methodological or infrastructural requirements. With the present study, we aimed to test the feasibility of a simple and accessible JBT for non-human primates and to investigate its sensitivity to affective states. Eight brown capuchins (Sapajus apella) and eleven Tonkean macaques (Macaca tonkeana) were tested under positive and negative affective conditions. Individuals were trained to discriminate between never rewarded conditioned stimuli and always rewarded ones. They were then presented with ambiguous probes they had never seen before to analyse their responses to ambiguity. The discrimination training required, on average, about 12 sessions lasting a few minutes each to successfully train every individual animal. Both species significantly discriminated between conditioned stimuli and ambiguous probes. Additionally, macaques showed a greater tendency to interact with the never rewarded condition stimuli and the probes under positive conditions during early sessions. In capuchins, however, the affective conditions presented had no significant effect, although the descriptive analysis tended to show that the latency to investigate the probes was greater in the negative condition. This study also highlights key methodological considerations, such as a decrease in ambiguity across sessions. Overall, the present results suggest that, with a few improvements, this method could be effectively implemented to assess affective states of primates under human care, supporting this tool as a valuable candidate for welfare assessment.

animal behavior and cognition↗

bioRxiv2026

Social or non-social? An exploratory approach to study inequity aversion in primates

Inequity aversion, the sensitivity to inequitable outcomes or processes, has been widely studied in nonhuman primates since 2003. Yet, findings remain debated as some could be explained by alternative mechanisms such as frustration or loss aversion, so-called individual contrasts. Previous work on nonhuman animals has restricted the definition of inequity aversion to the social domain. Here, we propose distinguishing between two different forms: a socially driven form, which depends on comparison with another individual, and an individually based form, caused by a discrepancy between ones own effort and the expected outcome. Using a task-based methodology, we manipulated both effort and the amount of reward to test for the existence of those different forms and distinguish them from individual contrasts. We presented seven Tonkean macaques (Macaca tonkeana) and three brown capuchins (Sapajus apella) with low and high effort tasks associated with low and high reward quantities. To test for the presence of individually based inequity aversion, subjects were tested alone in an individual phase. In some of the trials, they were rewarded less than they deserved for the task. To test for socially based inequity aversion, two individuals performed the same task in a social phase but, in some trials, one received a higher-value reward than the other. We recorded the latency to engage in the task as an indicator of reluctance. In the individual phase, macaques were slower to engage with inequitably rewarded tasks, a pattern consistent with an individually based expectation of equity. By contrast, capuchins were faster in this context, suggesting that their responses were more likely driven by individual contrast effects. In a context of social inequity, both species slowed engagement in tasks with inequitable rewards, suggesting an aversion to socially based inequity. These results demonstrate that such a methodology provides a means to study non-social components of inequity aversion. Future studies, conducted on larger and more diverse samples, with rigorous motivational controls and explicit tests looking at the understanding of the link between task and reward, are needed to confirm whether nonhuman primates can display inequity aversion independently of social comparison.

animal behavior and cognition↗

bioRxiv2026

Who takes the risk to forage? Testing consistent inter-individual behavioural variation in wild vervet monkeys (Chlorocebus pygerythrus)

Risk-taking behaviour permeates daily decision-making across many taxa and has significant impact on fitness outcomes. Previous research finds that individuals display consistent tendencies in their propensity to take risks, often labelled as a "Boldness-Shyness" personality trait. In this experimental study, we investigated repeatability in risk-taking behaviour in 241 wild vervet monkeys by measuring their responses to capture threat (via human-initiated darting procedure) and predation threat (via two predator models). We further examined the influence of socio-demographic, group identity and hormonal factors on risk-taking behaviour. We found that multiple behavioural responses, including the likelihood of approaching a food source under threat, were consistent across contexts. Risk-taking behaviour was influenced by age, sex, dominance rank, and hormonal profiles: juveniles, males, and higher-ranking individuals were more likely to approach food under (perceived) predation risk. Additionally, we observed significant among-group differences, suggesting that individuals within the same social group exhibit similar risk sensitivities, potentially due to social facilitation or shared environmental effects. The findings contribute to our understanding of animal personality and the ecological and social drivers underlying variation in risk-related behaviours.

animal behavior and cognition↗

bioRxiv2025

From kin to spatial proximity conspecifics: social network reorganisation in developing juvenile vervet monkeys

Navigating social relationships is a primary determinant of fitness in group-living animals and thus the transition of individuals from infancy to fully fledged group members is marked by concomitant changes in interactions. This developmental trajectory is particularly relevant in primates, where individuals must navigate a social landscape composed of different types of relationships and interactions while gaining independence from their mothers. Yet, little is currently known about how different layers of sociality, like proximity and grooming interactions, co-develop during the sensitive juvenile phase. Here, we harness multilayer network analysis on observations from 18 wild vervet juveniles (4-36 months of age) from two social groups to dissect the maturation of the juvenile social network. We quantify developmental trajectories across three complementary scales: maternal dyadic interactions, individual network centrality, and global network topology. We find that social maturation is defined not by simple network expansion, but by structural reorganisation. Specifically, juveniles shed their early bias toward mothers and kin, replacing these primary bonds by social interactions aligning with spatial proximity. This restructuring is further modulated by socio-demographic traits. Higher maternal rank confers access to influential partners, while females are more central than males in grooming networks, foreshadowing adult social roles. By charting the reorganisation of multiple social layers, this study unravels the processes underpinning the juvenile transition to independence in primates.

animal behavior and cognition↗

bioRxiv2024

When monkeys meet an ANYmal robot in the wild

Animal-robot interaction studies have been of increasing interest in research, but most of these studies have involved robots interacting with insects, birds, and frogs in laboratory settings. To date, only two studies used non-human primates and no behavioral study has tested the social integration of a robot in a group of wild primates. To fill this gap, we studied the interactions between the quadruped ANYmal robot and a group of 37 wild vervet monkeys in South Africa. The ANYmal robot is a remote-controlled sheep-sized robot with an open box of food on its back. We gradually introduced the robot to the monkeys following five different steps over 6 days for a total exposition time of about 10h. The monkeys habituated to the robot very quickly with six individuals eating the food in the robots box from the second day. A few individuals, mostly juveniles, emitted alarm calls towards the robot. In total, seven individuals, high rankers, spent time near the robot and 21 monkeys approached the robot from a greater distance. High rankers displayed significantly more vigilant and self-centered behaviors and they, with females and juveniles, ate more food in the robots box compared to low rankers, males, and adults conversely. This study offers exciting perspectives on the phenomena of social acceptance of machines in mammalian societies and the automation of field data collection.

animal behavior and cognition↗

bioRxiv2023

Social dynamics of vervet monkeys are dependent upon group identity.

Traditions are widespread across the animal realm. Here, we investigated inter-group variability of social dynamics in wild vervet monkeys (Chlorocebus pygerythrus). We analysed 84 704 social behavioural interactions involving 247 individuals collected over nine years in three neighbouring groups of wild vervet monkeys. We found that, in one group - Ankhase - individuals had a higher propensity to be affiliative (i.e., sociality) and grooming interactions were more reciprocal. Despite yearly fluctuations in sociality, differences between groups remained stable over time. Moreover, our statistical model predictions confirmed that these findings were maintained for similar sex ratios, age distributions and group sizes. Strikingly, our results suggested that dispersing males adapted their sociality to the sociality of the group they integrated with. As a whole, our study sheds light on the existence of stable social dynamics dependent upon group identity in wild vervet monkeys and suggests that at least part of this variability is socially mediated. Graphical Abstract HighlightsO_LIThe sociality of vervet monkeys groups differs consistently across a nine years study despite similar genetic and ecological environments. C_LIO_LIDispersing males adapt their sociality according to the group they integrate with. C_LIO_LIIn the most social group, grooming interactions were more reciprocal. C_LI

animal behavior and cognition↗

bioRxiv2021

Role of immigrants and muzzle contacts in the uptake of a novel food by wild vervet monkeys

The entry into and uptake of information in social groups is critical for behavioural adaptation by long-lived species in rapidly changing environments. We exposed five groups of wild vervet monkeys to a novel food to investigate innovation of processing and consuming it. We report that immigrant males innovated in two groups, and an infant innovated in one group. In two other groups, immigrant males imported the innovation from their previous groups. We compared uptake between groups with respect to the initial innovator to examine the extent to which dispersing males could introduce an innovation into groups. Uptake of the novel food was faster in groups where immigrant males ate first rather than the infant. Younger individuals were more likely overall, and faster, to subsequently acquire the novel food. We also investigated the role of muzzle contact behaviour in information seeking around the novel food. Muzzle contacts decreased in frequency over repeated exposures to the novel food. Muzzle contacts were initiated the most by naive individuals, high rankers and juveniles; and were targeted most towards knowledgeable individuals and high rankers, and the least towards infants. We highlight the potential importance of dispersers in rapidly exploiting novel resources among populations.

animal behavior and cognition↗

bioRxiv2020

Processing of novel food reveal payoff and rank-biased social learning in a wild primate

Social learning - learning from others - is the basis for behavioural traditions. Different social learning strategies (SLS), where individuals biasedly learn behaviours based on their content or who demonstrates them, may increase an individuals fitness and generate behavioural traditions. While SLS have been mostly studied in isolation, their interaction and the interplay between individual and social learning is less understood. We performed a field-based open diffusion experiment in a wild primate. We provided two groups of vervet monkeys with a novel food, unshelled peanuts, and documented how three different peanut opening techniques spread within the groups. We analysed data using hierarchical Bayesian dynamic learning models that explore the integration of multiple SLS with individual learning. We i) report evidence of social learning compared to strictly individual learning, ii) show that vervets preferentially socially learn the technique that yields the highest observed payoff and iii) also bias attention toward individuals of higher rank. This shows that behavioural preferences can arise when individuals integrate social information about the efficiency of a behaviour alongside cues related to the rank of a demonstrator. When these preferences converge to the same behaviour in a group, they may result in stable behavioural traditions.

animal behavior and cognition↗