Multimodal signalling in wild and captive orangutans: redundancy versus complementarity

动物通过使用视觉、听觉、嗅觉和其他信号，在每一种感觉通道中使用多分量信号与同种和异种特异体进行交流。尽管越来越多的证据表明，人类语言进化的主要模式--非人灵长类动物的交流本质上是多模式的，但大多数研究都是孤立地关注手势或发声。然而，为什么我们活着的最亲密的亲戚应该用一种或多种方式发出信号，人们仍然知之甚少。到目前为止，我们对多模式信号传递的功能知之甚少，对社会生态环境对交际行为的进化影响也知之甚少。此外，多通道信号产生和感知的个体发生对于理解交际行为的最近和最终机制是必不可少的。然而，发展研究仅限于多模式信号知觉，而信号产生一直被忽视。鉴于越来越多的证据表明社会经验对交流发展有很大的影响，理解学习在多模式信号产生中的作用是至关重要的。拟议的项目旨在通过研究类人猿如何以及为什么在种内交流中使用不同模式的信号成分来填补这些空白。在这项研究中，我将第一次在类人猿身上系统地测试主要的相互竞争的假说(“备份信号”和“多重信息”)。我将应用多通道发育的方法来研究野生和圈养猩猩(Pongo abelii/pygmaeus)多通道交流的功能和个体发育。由于猩猩在社交能力和树种现实方面的种内差异，我可以研究社会机会和生态环境在多大程度上影响交流行为。具体地说，我将调查和比较圈养和野外两种猩猩对单峰和多峰信号的产生和反应，以便在高度不同的社会和生态环境之间进行比较(2x2比较)。此外，我将把所获得的结果与潘物种、黑猩猩和矮黑猩猩的相应数据进行比较。通过这三个方面的比较(婆罗洲-苏门答腊岛，弗里兰-动物园，蓬戈潘)，我可以研究类人猿的交流行为与其社会生态生活方式的联系程度。反过来，这可能会为人类语言作为多模式系统的一部分的进化，以及手势、面部表情和眼睛凝视等伴随语音的信号的功能提供新的见解。

Animals communicate with con- and hetero-specifics using multicomponent signals in every sensory modality, employing visual, audible, olfactory and other signals. Despite growing evidence that the communication of nonhuman primates, our main model for the evolution of language, is intrinsically multimodal, most studies have focused on gesture or vocalization in isolation. However, why our closest living relatives should signal in single or multiple modalities is still poorly understood. So far we know very little about the function of multimodal signalling, and the evolutionary implications of the socio-ecological environment acting on communicative behaviour are poorly understood. Moreover, the ontogeny of multimodal signal production and perception is essential for an understanding of the proximate and ultimate mechanisms underlying communicative acts. Developmental research is however limited to multimodal signal perception, while signal production has been neglected. Given the growing evidence for a strong impact of social experience on communicative development, it is vital to understand the role of learning for multimodal signal production.The proposed project is designed to fill these gaps by examining how and why great apes use signal components of different modalities in intra-specific communication. In this study, I will for the first time systematically test the major competing hypotheses (‘backup signals’ versus ‘multiple messages’) in great apes. I will apply a multimodal-developmental approach to investigate function and ontogeny of multimodal communication in wild and captive orangutans (Pongo abelii/pygmaeus). Due to the orangutans’ intraspecific differences in sociability and their arboreality, I can examine to which extent social opportunities and ecological environment influence communicative behaviour. Specifically, I will investigate and compare the production of and responses to unimodal and multimodal signals in both species of orangutans in captivity and in the wild, allowing for the comparison between highly different social and ecological settings (2x2 comparison). In addition, I will compare the obtained results to corresponding data from the Pan species, chimpanzees and bonobos. With this threefold comparison (Borneo-Sumatra, Freiland–Zoo, Pongo-Pan), I can examine the extent to which the communicative behavior of great apes is linked to their socio-ecological lifestyle. In turn, this might provide novel insights on the evolution of human language as part of a multimodal system and the function of speech-accompanying signals like gestures, facial expressions and eye gaze.