<b>Note Repertoire and Age-sex Differences in the Vocalizations of </b><b><i>Sapajus libidinosus</i></b>

AbstractDocumenting the size and variety of a species’ vocal and note repertoires is fundamental for a better understanding of the diversity, function, and importance of primate calls. Sapajus libidinosus is widely known for its cognitive complexity, including tool use, and is therefore expected to present a large and complex acoustic repertoire. We describe the acoustic communication of S. libidinosus and test for differences in vocal parameters between contexts, sexes, and developmental stages. We also present the species’ note repertoire and its acoustic parameters. We recorded and extracted spectral and temporal parameters of 265 calls, with the sender’s sex and developmental stage, and the context of call emission. We identified 16 calls composed of eight different notes, with four calls presenting a combination of different notes. Juveniles presented calls with higher frequency and shorter duration than adults. Males presented calls with higher frequency and longer duration than females. These differences in acoustic proprieties may relate to traits, such as body size, and social roles. The use of the same note in different calls could represent an important evolutionary strategy in primates, allowing the creation of multiple calls without mechanical or neurological constraints. This understanding of note use, and its apparent combinatorial patterns, provides the foundation for future investigations of whether the underlying patterns indicate syntactic rules and whether they convey complex semantic information.<br><br>DOI: 10.1007/s10764-025-00513-2摘要：记录一个物种种群的发声与鸣唱曲目规模及多样性，是深入理解灵长类动物叫声的多样性、功能与重要性的基础。白面卷尾猴（Sapajus libidinosus）以认知复杂性闻名，其行为包括工具使用，因此被认为拥有庞大且复杂的声学曲目。本研究描述了白面卷尾猴的声学通信行为，并检验了不同情境、性别以及发育阶段下发声参数的差异。此外，本研究还呈现了该物种种群的鸣唱曲目及其声学参数。研究人员记录并提取了265次发声的频谱与时域参数，同时记录了发声个体的性别、发育阶段以及发声情境。研究共识别出16种由8种不同鸣唱单元组成的发声类型，其中4种发声类型由不同鸣唱单元组合而成。幼体的发声频率高于成体，且持续时长更短；雄性的发声频率高于雌性，且持续时长更长。这些声学特性的差异可能与体型、社会角色等特征相关。在不同发声类型中使用相同鸣唱单元，可能代表灵长类动物的一项重要进化策略，使其能够在不受机械或神经限制的前提下生成多种发声类型。对鸣唱单元使用方式及其明显组合模式的理解，为未来研究奠定了基础：即这些潜在模式是否体现句法规则，以及它们是否传递复杂的语义信息。 DOI: 10.1007/s10764-025-00513-2