Maternal effects on the development of vocal communication in wild chimpanzees.
Ontology highlight
ABSTRACT:
SUBMITTER: Brundl AC
PROVIDER: S-EPMC9550609 | biostudies-literature | 2022 Oct
REPOSITORIES: biostudies-literature
Publications
Maternal effects on the development of vocal communication in wild chimpanzees.
Bründl Aisha C AC Girard-Buttoz Cédric C Bortolato Tatiana T Samuni Liran L Grampp Mathilde M Löhrich Therese T Tkaczynski Patrick P Wittig Roman M RM Crockford Catherine C
iScience 20220919 10
Early-life experiences, such as maternal care received, influence adult social integration and survival. We examine what changes to social behavior through ontogeny lead to these lifelong effects, particularly whether early-life maternal environment impacts the development of social communication. Chimpanzees experience prolonged social communication development. Focusing on a central communicative trait, the "pant-hoot" contact call used to solicit social engagement, we collected cross-sectiona ...[more]
Similar Datasets
Project description:BackgroundPatterns of vocal communication have implications for species conservation: a change in calling behaviour can, for instance, reflect a disturbed habitat. More importantly, call rate is a parameter that allows conservation planners to convert call density into animal density, when detecting calls with a passive acoustic monitoring system (PAM).MethodsWe investigated chimpanzee (Pan troglodytes schweinfurthii) call rate during the late dry season in the Issa Valley, western Tanzania by conducting focal follows. We examined the socio-ecological factors that influence call production rate of savanna woodland chimpanzees.ResultsWe found that sex, proportion of time spent in a vegetation type, proportion of time spent travelling, time of the day, party size and swollen parous female presence had a significant effect on the call rate. Call rate differed among the different demographic classes with subadult and adult males vocalising twice as often as the subadult and adult females and three times as often as the juveniles.ApplicationsThe use of PAM and recent statistical developments to estimate animal density is promising but relies on our knowing individual call rate, often not available for many species. With the improvement in automatic call detection, we anticipate that PAM will increasingly be broadly applied to primates but also across taxa, for conservation.
| S-EPMC8532989 | biostudies-literature
Project description:AbstractAnimals have evolved a range of communicative behaviours in the presence of danger. Although the mechanisms and functions of some of these behaviours have been relatively well researched, comparatively little is known about their ontogeny, including how animals learn to inform social partners about impending danger. In adult chimpanzees, behaviours in response to dangers involve several channels, particularly alarm calls and simultaneous gaze alternations with nearby recipients. Gaze alternations may allow inexperienced individuals to learn from more experienced ones by assessing their reactions to unfamiliar objects or events, but they may also provide the basis for more advanced social referencing. Here, we were interested in the development of these two common behaviours, alarm calling and gaze alternations, in wild chimpanzees (Pan troglodytes schweinfurthii) confronted with a threat. Using a cross-sectional design, we investigated those in 8 infant and 8 juveniles by experimentally exposing them to an unfamiliar but potentially dangerous object, a large, remotely controlled, moving spider model. For alarm calling, we found a positive relation with age, starting at around 28 months, although alarm calls were not consistently emitted until after 80 months. For gaze alternations, we found no age effect, with some of the youngest infants already showing the behaviour. Although its function remains unclear in infant and juvenile chimpanzees, gaze alternations emerge early in chimpanzee development. Alarm calling may require more advanced developmental stages, such as greater perceptual abilities, categorical capacities or more sophisticated social cognition, i.e. an understanding that danger is a collective experience that requires communication.Significance statementAlarm calling and other anti-predatory behaviours have been the topic of much research but their ontogenies are still poorly described and understood. Recent studies on the behaviour of wild chimpanzees in threatening contexts have suggested sophisticated social cognitive abilities in adults. How do these behaviours develop in ontogeny? We addressed this question using a field experiment with 8 infants and 8 juveniles exposed to a novel and potentially threatening object in their natural habitat. We found that gaze alternations are present in some of the youngest individuals, potentially revealing early social awareness in chimpanzees. Age did not have an effect on the presence of gaze alternation. We also found that alarm calling was more common in older individuals, suggesting that call production and context of usage must be learnt. We discuss our results in light of developmental theories of social cognition and the role of social learning in the primate lineage.
| S-EPMC6612320 | biostudies-literature
Project description:Joint travel is a common social activity of many group-living animals, which requires some degree of coordination, sometimes through communication signals. Here, we studied the use of an acoustically distinct vocalisation in chimpanzees, the 'travel hoo', a signal given specifically in the travel context. We were interested in how this call type was produced to coordinate travel, whether it was aimed at specific individuals and how recipients responded. We found that 'travel hoos' were regularly given prior to impending departures and that silent travel initiations were less successful in recruiting than vocal initiations. Other behaviours associated with departure were unrelated to recruitment, suggesting that 'travel hoos' facilitated joint travel. Crucially, 'travel hoos' were more often produced in the presence of allies than other individuals, with high rates of recruitment success. We discuss these findings as evidence for how motivation to perform a specific social activity can lead to the production of a vocal signal that qualifies as 'intentional' according to most definitions, suggesting that a key psychological component of human language may have already been present in the common ancestor of chimpanzees and humans.
| S-EPMC3783376 | biostudies-literature
Project description:Cooperation and communication likely coevolved in humans. However, the evolutionary roots of this interdependence remain unclear. We address this issue by investigating the role of vocal signals in facilitating a group cooperative behavior in an ape species: hunting in wild chimpanzees. First, we show that bark vocalizations produced before hunt initiation are reliable signals of behavioral motivation, with barkers being most likely to participate in the hunt. Next, we find that barks are associated with greater hunter recruitment and more effective hunting, with shorter latencies to hunting initiation and prey capture. Our results indicate that the coevolutionary relationship between vocal communication and group-level cooperation is not unique to humans in the ape lineage and is likely to have been present in our last common ancestor with chimpanzees.
| S-EPMC9337754 | biostudies-literature
Project description:A key driver of brain evolution in primates and humans is the cognitive demands arising from managing social relationships. In primates, grooming plays a key role in maintaining these relationships, but the time that can be devoted to grooming is inherently limited. Communication may act as an additional, more time-efficient bonding mechanism to grooming, but how patterns of communication are related to patterns of sociality is still poorly understood. We used social network analysis to examine the associations between close proximity (duration of time spent within 10 m per hour spent in the same party), grooming, vocal communication, and gestural communication (duration of time and frequency of behavior per hour spent within 10 m) in wild chimpanzees. This study examined hypotheses formulated a priori and the results were not corrected for multiple testing. Chimpanzees had differentiated social relationships, with focal chimpanzees maintaining some level of proximity to almost all group members, but directing gestures at and grooming with a smaller number of preferred social partners. Pairs of chimpanzees that had high levels of close proximity had higher rates of grooming. Importantly, higher rates of gestural communication were also positively associated with levels of proximity, and specifically gestures associated with affiliation (greeting, gesture to mutually groom) were related to proximity. Synchronized low-intensity pant-hoots were also positively related to proximity in pairs of chimpanzees. Further, there were differences in the size of individual chimpanzees' proximity networks-the number of social relationships they maintained with others. Focal chimpanzees with larger proximity networks had a higher rate of both synchronized low- intensity pant-hoots and synchronized high-intensity pant-hoots. These results suggest that in addition to grooming, both gestures and synchronized vocalizations may play key roles in allowing chimpanzees to manage a large and differentiated set of social relationships. Gestures may be important in reducing the aggression arising from being in close proximity to others, allowing for proximity to be maintained for longer and facilitating grooming. Vocalizations may allow chimpanzees to communicate with a larger number of recipients than gestures and the synchronized nature of the pant-hoot calls may facilitate social bonding of more numerous social relationships. As group sizes increased through human evolution, both gestures and synchronized vocalizations may have played important roles in bonding social relationships in a more time-efficient manner than grooming.
| S-EPMC5121241 | biostudies-literature
Project description:The extent to which primates can flexibly adjust the production of gestural communication according to the presence and visual attention of the audience provides key insights into the social cognition underpinning gestural communication, such as an understanding of third party relationships. Gestures given in a mating context provide an ideal area for examining this flexibility, as frequently the interests of a male signaller, a female recipient and a rival male bystander conflict. Dominant chimpanzee males seek to monopolize matings, but subordinate males may use gestural communication flexibly to achieve matings despite their low rank. Here we show that the production of mating gestures in wild male East African chimpanzees (Pan troglodytes schweunfurthii) was influenced by a conflict of interest with females, which in turn was influenced by the presence and visual attention of rival males. When the conflict of interest was low (the rival male was present and looking away), chimpanzees used visual/ tactile gestures over auditory gestures. However, when the conflict of interest was high (the rival male was absent, or was present and looking at the signaller) chimpanzees used auditory gestures over visual/ tactile gestures. Further, the production of mating gestures was more common when the number of oestrous and non-oestrus females in the party increased, when the female was visually perceptive and when there was no wind. Females played an active role in mating behaviour, approaching for copulations more often when the number of oestrus females in the party increased and when the rival male was absent, or was present and looking away. Examining how social and ecological factors affect mating tactics in primates may thus contribute to understanding the previously unexplained reproductive success of subordinate male chimpanzees.
| S-EPMC4633128 | biostudies-literature
Project description:The adoption of unrelated orphaned infants is something chimpanzees and humans have in common. Providing parental care has fitness implications for both the adopter and orphan, and cases of adoption have thus been cited as evidence for a shared origin of an altruistic behaviour. We provide new data on adoptions in the free-living Sonso chimpanzee community in Uganda, together with an analysis of published data from other long-term field sites. As a default pattern, we find that orphan chimpanzees do not become adopted by adult group members but wherever possible associate with each other, usually as maternal sibling pairs. This occurs even if both partners are still immature, with older individuals effectively becoming 'child household heads'. Adoption of orphans by unrelated individuals does occur but usually only if no maternal siblings or other relatives are present and only after significant delays. In conclusion, following the loss of their mother, orphaned chimpanzees preferentially associate along pre-existing social bonds, which are typically strongest amongst maternal siblings.
| S-EPMC4118915 | biostudies-literature
Project description:AbstractWe describe the individual and combined use of vocalizations and gestures in wild chimpanzees. The rate of gesturing peaked in infancy and, with the exception of the alpha male, decreased again in older age groups, while vocal signals showed the opposite pattern. Although gesture-vocal combinations were relatively rare, they were consistently found in all age groups, especially during affiliative and agonistic interactions. Within behavioural contexts rank (excluding alpha-rank) had no effect on the rate of male chimpanzees' use of vocal or gestural signals and only a small effect on their use of combination signals. The alpha male was an outlier, however, both as a prolific user of gestures and recipient of high levels of vocal and gesture-vocal signals. Persistence in signal use varied with signal type: chimpanzees persisted in use of gestures and gesture-vocal combinations after failure, but where their vocal signals failed they tended to add gestural signals to produce gesture-vocal combinations. Overall, chimpanzees employed signals with a sensitivity to the public/private nature of information, by adjusting their use of signal types according to social context and by taking into account potential out-of-sight audiences. We discuss these findings in relation to the various socio-ecological challenges that chimpanzees are exposed to in their natural forest habitats and the current discussion of multimodal communication in great apes.Significance statementAll animal communication combines different types of signals, including vocalizations, facial expressions, and gestures. However, the study of primate communication has typically focused on the use of signal types in isolation. As a result, we know little on how primates use the full repertoire of signals available to them. Here we present a systematic study on the individual and combined use of gestures and vocalizations in wild chimpanzees. We find that gesturing peaks in infancy and decreases in older age, while vocal signals show the opposite distribution, and patterns of persistence after failure suggest that gestural and vocal signals may encode different types of information. Overall, chimpanzees employed signals with a sensitivity to the public/private nature of information, by adjusting their use of signal types according to social context and by taking into account potential out-of-sight audiences.
| S-EPMC5446553 | biostudies-literature
Project description:A key challenge for primates is coordinating behaviour with conspecifics in large, complex social groups. Gestures play a key role in this process and chimpanzees show considerable flexibility communicating through single gestures, sequences of gestures interspersed with periods of response waiting (persistence), and rapid sequences where gestures are made in quick succession, too rapid for the response waiting to have occurred. The previous studies examined behavioural reactions to single gestures and sequences, but whether this complexity is associated with more complex sociality at the level of the dyad partner and the group as a whole is not well understood. We used social network analysis to examine how the production of single gestures and sequences of gestures was related to the duration of time spent in proximity and individual differences in proximity in wild East African chimpanzees (Pan troglodytes schweinfurthii). Pairs of chimpanzees that spent a longer duration of time in proximity had higher rates of persistence sequences, but not a higher rate of single gestures or rapid sequences. The duration of time spent in proximity was also related to the rate of responding to gestures, and response to gesture by activity change. These results suggest that communicative persistence and the type of response to gestures may play an important role in regulating social interactions in primate societies.
| S-EPMC6689904 | biostudies-other
Project description:Maternal cannibalism has been reported in several animal taxa, prompting speculations that the behavior may be part of an evolved strategy. In chimpanzees, however, maternal cannibalism has been conspicuously absent, despite high levels of infant mortality and reports of non-maternal cannibalism. The typical response of chimpanzee mothers is to abandon their deceased infant, sometimes after prolonged periods of carrying and grooming the corpse. Here, we report two anomalous observations of maternal cannibalism in communities of wild chimpanzees in Uganda and Ivory Coast and discuss the evolutionary implications. Both infants likely died under different circumstances; one apparently as a result of premature birth, the other possibly as a result of infanticide. In both cases, the mothers consumed parts of the corpse and participated in meat sharing with other group members. Neither female presented any apparent signs of ill health before or after the events. We concluded that, in both cases, cannibalizing the infant was unlikely due to health-related issues by the mothers. We discuss these observations against a background of chimpanzee mothers consistently refraining from maternal cannibalism, despite ample opportunities and nutritional advantages. We conclude that maternal cannibalism is extremely rare in this primate, likely due to early and strong mother-offspring bond formation, which may have been profoundly disrupted in the current cases.
| S-EPMC7080684 | biostudies-literature