Biology subjects

Bande, N.

Publications and source records attributed to Bande, N..

3 recordsLinked to original sources

bioRxiv2026

Risk management strategies in social grooming among Tonkean and rhesus macaques

Group-living individuals interact constantly, maintaining cohesion, stability, and security within their social groups. However, these interactions can entail risks that individuals must manage to optimize their social navigation through complex social groups, such as those of non-human primates. Here, we investigated how macaques manage risk during social grooming by analysing its somatic modalities, including body orientation and body site being groomed. We compared two macaque species with contrasting social styles: the more despotic rhesus macaque and the more tolerant Tonkean macaque. Using dyadic analyses including species, kinship, age difference, rank difference, and male presence as predictors, we found marked species differences in grooming patterns. Tonkean macaques engaged more frequently in face-to-face grooming and less in face-to-back grooming compared to rhesus macaques. They also groomed body sites associated with high eye-contact probability, such as the head, neck, and chest, more often than rhesus macaques. Kin dyads groomed these body sites more often, particularly in rhesus macaques. These findings suggest that avoiding body sites associated with potential eye-contact may constitute a risk management strategy during grooming. Overall, our results reveal a previously overlooked dimension of primate social cognition that may shape dyadic relationships and social network structure.

animal behavior and cognition↗

bioRxiv2025

Living with urban fear: vervet monkey response to an evolutionarily new predator

Humans have facilitated contacts between prey and predator species that have originally not co-evolved, reshuffling the prey-predator arms race. How do prey cope with an evolutionarily new predation risk? We tracked three vervet monkey troops in a South-African semi-urban habitat for 14 months to study their response to domestic dogs. We show that monkeys responded to dogs with a two-pronged behaviour: they emitted alarm calls, and became more vigilant and displayed aggressive behaviours towards the dogs. While their movement highlighted risk-prone behaviour, they appeared to have mapped and planned for risk, as they reacted more strongly when risk was unexpected. The response intensity was further modulated by risk labels typically encountered in their natural environment, but not by labels uniquely associated with dogs. This highlights that vervet monkeys responded with ingrained behaviour to this evolutionarily new threat, anticipating risk based on long-term spatial memory, but failed to integrate evolutionarily new information. TeaserVervet monkeys fear domestic dogs but fail to adjust their antipredator response by discriminating evolutionarily new risk labels.

animal behavior and cognition↗

bioRxiv2025

Rule-based sequences in sooty mangabey vocal communication

Investigating how non-human animals produce call sequences provides key insights into the evolutionary origins of meaning in vocal communication, including syntax. Many species combine calls into structured sequences, often following specific rules, yet most studies focus on only a few sequences per species. This limits our understanding of their ability to combine calls and convey meaning through sequences. Our study addresses this gap by documenting the vocal sequence repertoire and underlying rules of sooty mangabeys (Cercocebus atys), a West African monkey species. We collected and analysed 1,672 recordings from two wild groups in the Tai National Park, Ivory Coast. Sooty mangabeys frequently combine calls but rely on a limited set of sequences. Within these, we identified rules of call ordering, recurrence and hierarchical structuring. Notably, they produced hierarchically structured sequences using only two call types, a previously unreported system in animal communication. Our findings suggest that sooty mangabeys use both structured and unstructured sequences, likely encoding different types of information. While context of production remains essential for determining meaning, our results highlight how a whole-repertoire approach reveals the full range of rule-based sequences and their potential for meaning expansion beyond the number of individual calls available in the repertoire.

animal behavior and cognition↗