Biology subjects

Wewhare, N.

Publications and source records attributed to Wewhare, N..

4 recordsLinked to original sources

bioRxiv2026

Sequence-level vocal convergence in common marmosets

Vocal accommodation is the process by which individuals adjust their vocalizations to resemble those of social partners. This phenomenon is widespread in social animals and can reinforce affiliation, signal group identity, and facilitate coordination. Most studies of vocal accommodation have focused on convergence in the acoustic structure of individual calls. Whether social partners also converge in how calls are arranged into sequences remains largely unknown. We examined vocal convergence during pair formation in common marmosets (Callithrix jacchus) by recording phee sequences from nine dyads composed of three males and three females before pairing and again four months after, in two audience contexts: when individuals interacted vocally with their partner or with an opposite sex stranger. We quantified similarity between individuals in call sequence-structure using transition probabilities, bigram frequencies, repeat-length distributions, and local alignment, and quantified similarity in acoustic structure using spectral parameters, MFCCs, and dynamic time warping. We found vocal convergence on a sequence level. After pair formation, partners became more similar in sequence structure when calling to strangers, whereas no change was detected in partner directed sequences. In contrast, call acoustic structure did not change in either context. Because vocal repertoires are constrained by anatomy and physiology, reorganizing existing call types into different combinations may provide a flexible route for modifying signals without altering the acoustic structure of individual calls. Our results provide evidence that social bonds can drive sequence level vocal convergence in a non-human primate, suggesting that vocal flexibility may arise not only through changes in acoustic structures but also through changes in how calls are organized over time.

animal behavior and cognition↗

bioRxiv2025

Vocal sequences of diverse parrots suggest an important role for note repetition

Sequencing and syntax in complex animal vocal signals have been studied using several mathematical analyses. Commonly, sequences of vocalizations are assumed to follow a first-order Markov process, where each state depends on the state immediately before it. However, more recent computational analyses challenge this assumption, suggesting alternative processes may be important in vocal sequences. Open-ended vocal learners such as parrots possess complex, variable vocal sequences that may be dynamically modified throughout their lives and contain information about group membership and identity. Although this makes them important systems in which to identify general patterns within vocal sequences, parrot vocalizations remain generally understudied compared to passerine birds. Here, we examined vocal sequence structure in six species of parrots (Psittaculidae). We fit various metrics of sequence structure to those generated by multiple simulated processes, including Markov, random, hidden Markov and renewal processes. Two metrics exhibited the best fit to a renewal process (where a note repeats a certain number of times before transitioning to a new note), and two others to Markov processes. Importantly, all analyses were broadly concordant across species, and multiple metrics indicated an elevated probability of note repetition. Reconciling these results, we suggest a general vocal mechanism across the highly variable vocal sequences of parrots, where both note repetition and Markov processes are important. Note repetition patterns could help communicate individual or group identity, as well as social and behavioral context. Our study thus extends a simulation-based approach using diverse metrics to comparatively examine the complex, variable vocal sequences of these open-ended vocal learners.

animal behavior and cognition↗

bioRxiv2024

Individual-specific associations between behavioral events and song notes shape budgerigar vocal sequences

Complex behavioral sequences such as courtship displays are often multimodal, and coordination between modalities is critically important. However, in learned and variable behavioral sequences such as songs, individual variability may extend to multimodal coordination. However, individual variability in complex multimodal sequences and in coordination between distinct behaviors remains underexplored. Here, we report that budgerigars, which continuously learn and modify their complex warble songs, exhibit associations between behavioral events during courtship and song notes. Some associations are unique to individuals, and others are universal across individuals. Additionally, some individuals exhibit more unique associations than others. We also find that birds warbling without courtship emit all notes with broadly similar odds ratios. The presence of individual variability opens up the possibility that social learning may modify the associations between complex sequences of behaviors, and this results in both individual variability and hierarchical differences in the links between courtship or copulatory behaviors and song.

animal behavior and cognition↗

bioRxiv2022

Higher-order dialectic variation and syntactic convergence in the complex warble song of budgerigars

Dialectic signatures in animal acoustic signals are key in identification and association with group members. Complex vocal sequences may also convey information about behavioral state, and may thus vary according to social environment. Many bird species learn and modify their complex acoustic signals throughout their lives. However, the structure and function of vocal sequences in perennial vocal learners remains understudied. Here, we examined vocal sequence variation in the warble song of budgerigars, and how these change upon contact between social groups. Budgerigars are perennial vocal learners which exhibit fission-fusion flock dynamics in the wild. We found that two captive colonies of budgerigars exhibited colony-specific differences in the syntactic structure of their vocal sequences. Individuals from the two colonies differed in the propensity to repeat certain note types, forming repetitive motifs which served as higher-order signatures of colony identity. When the two groups were brought into contact, their vocal sequences converged within months of contact, and these colony-specific repetitive patterns disappeared, with males from both erstwhile colonies now producing similar sequences with similar syntactic structure. Our data suggests that budgerigars can encode substantial information in the higher-order temporal arrangement of notes/vocal units, which is modified throughout life by social learning as groups of birds continually associate and dissociate. Our study sheds light on the importance of examining signal structure at multiple levels of organisation, and the potential for psittaciform birds as model systems to examine the influence of learning and social environment on acoustic signals.

animal behavior and cognition↗