Biology subjects

Wegdell, F.

Publications and source records attributed to Wegdell, F..

4 recordsLinked to original sources

bioRxiv2025

Great Ape Childhoods: Development of infant bonobos (Pan paniscus) and chimpanzees (Pan troglodytes schweinfurthii) in the wild

Human development is marked by extended immaturity, necessitating extended care throughout infancy and childhood, facilitating advanced cognitive, social, and cultural skill acquisition. Parallels of extended development are also present in our closest living relatives, bonobos (Pan paniscus) and chimpanzees (Pan troglodytes). The Self-Domestication Hypothesis (SDH) suggests that human uniqueness stems from selection against aggression. Bonobos are also considered self-domesticated, exhibiting lower aggression and greater social tolerance, which are linked to delayed development and prolonged maternal dependence compared to chimpanzees. However, systematic, quantitative comparisons of the two species developmental patterns are limited and conflicting. This study addressed this gap by examining behavioural development in bonobo and chimpanzee infants aged 0-5.5 years living in two populations (Kokolopori community, Kokolopori Bonobo Reserve, DRC, N=21; Ngogo community, Kibale National Park, Uganda, N=22) in their natural environments. We specifically focused on (i) general behaviours (travel, feeding, grooming), and (ii) spatial independence. By systematically comparing developmental data and using consistent methods, we tested whether bonobo development aligns with SDH predictions. Our results showed similar developmental trajectories, with no species differences concerning ventral riding, nipple contact, or grooming. However, we found species differences regarding travel and proximity patterns, with chimpanzees exhibiting prolonged dorsal riding, bonobos travelling independently more often and maintaining greater distances from their mothers. Age, sibling presence, and maternal parity influenced behavioural patterns, but no sex differences were observed. These findings challenge assumptions of slower bonobo maturation, and highlight the importance of systematic, collaborative research on primate behavioural diversity in natural environments.

animal behavior and cognition↗

bioRxiv2025

An updated vocal repertoire of wild adult bonobos (Pan paniscus )

While research over the last 20 years has shed important light on the vocal behaviour of our closest living relatives, bonobos and chimpanzees, a quantitative description of their full vocal repertoire is absent. Such data are critical for a holistic understanding of a species communication system and unpacking how these systems compare more broadly with other primate and non-primate species. Here we make key progress by providing the first quantitative Pan vocal repertoire, specifically for wild bonobos. Using data comprising over 1500 calls from 53 adult individuals collected over 33 months, we employ machine-learning-based random forest analyses and describe 11 acoustically distinguishable call types. We discuss issues associated with resolving vocal repertoires from wild data in great apes and highlight potential future approaches to further capture the complexity of the bonobo vocal system.

animal behavior and cognition↗

bioRxiv2020

Behavioural diversity of bonobo prey preference as a potential cultural trait

The importance of cultural processes to behavioural diversity, especially in our closest living relatives, is central for revealing the evolutionary origins of human culture. Whereas potential cultural traits are extensively investigated in chimpanzees, our other closest living relative, the bonobo, is often overlooked as a candidate model. Further, a prominent critique to many examples of proposed animal cultures is premature exclusions of environmental confounds known to shape behavioural phenotypes. We addressed these gaps by investigating variation in prey preference expression between neighbouring bonobo groups that associate and share largely overlapping home ranges. We find specific group preference for duiker or anomalure hunting that are otherwise unexplained by variation in spatial usage of hunt locations, seasonality or sizes of hunting parties. Our findings demonstrate that group-specific behaviours emerge independently of the local ecology, indicating that hunting techniques in bonobos may be culturally transmitted. We suggest that the tolerant intergroup relations of bonobos offer an ideal context to explore drivers of behavioural phenotypes, the essential investigations for phylogenetic constructs of the evolutionary origins of culture.Competing Interest StatementThe authors have declared no competing interest.View Full Text

animal behavior and cognition↗

bioRxiv2020

Vocal convergence in the multi-level society of Guinea baboons

The extent to which nonhuman primate vocalizations are amenable to modification through experience is relevant for understanding the substrate from which human speech evolved. We examined the vocal behaviour of Guinea baboons, Papio papio, ranging in the Niokolo Koba National Park in Senegal. Guinea baboons live in a multi-level society, with units nested within parties nested within gangs. We investigated whether the acoustic structure of grunts of 27 male baboons of two gangs varied with party/gang membership and genetic relatedness. Males in this species are philopatric, resulting in increased male relatedness within gangs and parties. Grunts from members were more similar within than across social levels (N = 351 dyads for comparison within and between gangs, and N = 169 dyads within and between parties), but the effect sizes were small. Yet, acoustic similarity did not correlate with genetic relatedness, suggesting that higher amounts of social interactions rather than genetic relatedness promote the observed vocal convergence. We consider this convergence a result of sensory-motor integration and suggest this to be an implicit form of vocal learning shared with humans, in contrast to the goal-directed and intentional explicit form of vocal learning unique to human speech acquisition.

animal behavior and cognition↗