HRRBAA: Infrasonic Communication in a Cryptic Primate

有广泛的证据表明，社会和声音的复杂性是共同进化的：当动物需要管理更长期的社会关系时，它们会有更多的叫声类型。根据这个逻辑，非常安静的L 'Hoest猴子是一种反常现象，因为尽管它们具有高度的社交性，但它们似乎只发出预期数量的10%的呼叫类型。新的初步证据反驳了之前关于这个物种只是安静的假设。相反，它的大部分交流可能集中在人类听不到的低频率上——即次声。本研究旨在制作高质量的L'Hoest猴子叫声录音，以记录次声在群体内交流中的日常使用。录音可以通过可公开访问的在线存储库传播。这些数据可以为未来的研究提供信息，研究体型相对较小的哺乳动物产生和感知这种信号的物理机制，可能形成这种交流系统的环境和社会压力，以及相关物种是否也使用次声。该项目将促进对本科生的培训和指导，包括来自STEM中代表性不足群体的个人。L 'Hoest的猴子面临着两个相互矛盾的挑战：作为体型相对较小的陆生动物，它们需要降低被猫科动物和其他食肉动物捕食的严重风险；然而，它们首选栖息地的茂密植被限制了它们与同伴的视觉接触，因此必须依靠声音信号来维持群体凝聚力。这个物种可能通过使用低频发声来适应这些压力，这些低频发声可能是捕食者听不到的。由于标准设备无法可靠地探测人类听觉范围之外的信号，因此需要专门的设备来创建声音文件作为这些信号的证据并探索其特征。这些音频文件与附近动物的同步视频和距离测量相匹配。总之，这些记录用于(1)对次声（20Hz）和近次声（20-40Hz）频率下的呼叫类型数量进行初步评估，(2)描述这些呼叫的声学特征，(3)记录与特定呼叫相关的行为背景，以及(3)确定低频信号的传输距离。本研究是对一种新型通信系统的初步评估，为今后的研究奠定了基础。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

There is widespread evidence that social and vocal complexity co-evolve: animals have larger repertoires of call types when they need to manage more long-term social relationships. By this logic, the very quiet L’Hoest’s monkeys are an anomaly because, despite being highly social, they appear to produce only 10% of the expected number of call types. New preliminary evidence contradicts previous assumptions that this species is merely quiet. Instead, most of its communication may be concentrated within such low frequencies that they are inaudible to humans – i.e., infrasound. This study is designed to produce high-quality recordings of L'Hoest's monkey calls to document routine use of infrasound for within-group communication. The recordings can be disseminated through publicly accessible, online repositories. The data can inform future studies of physical mechanisms by which relatively small-bodied mammals produce and perceive such signals, the environmental and social pressures likely to have shaped this communication system, and whether related species also use infrasound. The project will advance training and mentoring of undergraduates, including individuals from underrepresented groups in STEM.L’Hoest’s monkeys face two conflicting challenges: as relatively small-bodied, terrestrial animals, they need to reduce the severe risk of predation by felids and other carnivores; yet the dense vegetation of their preferred habitats limits their visual contact with group-mates, necessitating reliance on acoustic signals to maintain group cohesion. This species may have adapted to these pressures through the use of low-frequency vocalizations that are likely to be inaudible to predators. Specialized equipment is necessary to create sound files as evidence of these signals and to explore their characteristics, because standard equipment is unable to reliably detect signals outside the range of human hearing. These audio files are paired with simultaneous video and distance measurements to nearby animals. Together, these records are used to (1) make a preliminary assessment of the number of call types that occur in the infrasonic (20Hz) and near-infrasonic (20-40Hz) frequencies, (2) describe the acoustic characteristics of these calls, (3) document the behavioral context associated with specific calls, and (3) determine the transmission distance of low-frequency signals. This study is an initial assessment of a novel communication system and establishes a foundation for future research into this topic.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.