Olfactory cognition of social relationships in primates

嗅觉是进化上最古老的动物感觉之一，在许多哺乳动物的社会认知和交流中发挥着关键作用。嗅觉对社会生活的重要性在进化上更古老的灵长类动物中也得到了很好的证实，比如狐猴和懒猴。然而，卡特拉灵长类动物(东半球的猴子和类人猿)由于强烈的视觉定向，历来被认为对嗅觉的依赖很少。虽然这个概念越来越被认为是过时的，但它导致了在这些分类群中嗅觉研究的稀缺。这一点至关重要，因为卡特龙被认为是社会关系最复杂的灵长类动物。管理这些关系带来了相当大的认知挑战，需要动物获得关于相同细节的社会知识，并随着时间的推移跟踪自己和他人的社会互动。由于嗅觉线索可以提供其他感官领域(暂时)缺乏的社会信息，或者提高其他感官线索的精确度和可靠性，它们可能对管理这些复杂的关系做出重大贡献。尽管如此，卡他灵长类动物对社会属性和关系的识别主要是在视觉和听觉领域进行的研究。关于嗅觉在卡他类社会认知中的作用的研究严重缺乏，这在我们对灵长类交流和社会复杂性进化的理解上造成了很大的差距。因此，这项拟议的项目将评估巴巴里猕猴(Macaca Sylvanus)对社会关系的嗅觉认知。巴巴里猕猴是一种东半球猴子，拥有复杂的社会关系，已知可以通过视觉和听觉线索识别个人属性和社会关系。我们将采用一种强大的综合方法，将分析巴巴里猕猴气味的化学成分与同种气味的实验呈现相结合。为此，我们将使用最先进的非侵入性采样方案、高灵敏的气相色谱-质谱分析和公认的认知测试范例。特别是，我们将确定在生活在自然主义社会环境中的两个习惯性、半自由放养的种群中，可以从巴巴里猕猴的气味中获得哪些基本的(身份、亲属关系、等级)和派生的(第三方、群体组成)社会信息。通过将气味成分中包含的信息与猴子利用嗅觉线索识别个体属性和社会关系联系起来，该项目将大大有助于理解管理社会关系的嗅觉机制和认知基础，以及灵长类沟通和社会复杂性的进化。

The sense of smell is among the evolutionarily oldest of the animal senses and plays a pivotal role in social cognition and communication in numerous mammals. The importance of olfaction for social life is also well-established in evolutionarily older primate taxa such as lemurs and lorises. Catarrhine primates (Old World monkeys and apes), however, have historically been assumed to rely little on the sense of smell due to their strong visual orientation. Although this notion is increasingly considered outdated, it has resulted in a scarcity of olfactory studies in these taxa. This is vital insofar as catarrhines are considered to be the primates with the most complex social relationships. Managing these relationships poses considerable cognitive challenges, requiring animals to obtain social knowledge about conspecifics and to track their own and others' social interactions over time. As olfactory cues can provide social information that is (temporarily) absent in other sensory domains or enhance the precision and reliability of other sensory cues, they could contribute significantly to managing these intricate relationships. Even so, the recognition of social attributes and relationships in catarrhine primates has been studied primarily in the visual and auditory domain. This severe paucity of studies on the role of olfaction in catarrhine social cognition poses a significant gap in our understanding of primate communication and the evolution of social complexity. The proposed project will therefore assess olfactory cognition of social relationships in Barbary macaques (Macaca sylvanus), an Old World monkey with sophisticated social relationships known to recognize individual attributes and social relationships using visual and auditory cues. We will employ a powerful, integrative approach that combines analysing the chemical composition of Barbary macaque scents with experimental presentations of conspecific scents. To do so, we will use state-of-the art, non-invasive sampling protocols, highly sensitive gas chromatography-mass spectrometry analysis and well-established cognitive test paradigms. In particular, we will determine which basic (identity, kinship, rank) and derived (third-party, group composition) social information can be obtained from the scents of Barbary macaques in two habituated, semi-free ranging populations living in naturalistic social settings. By relating the information contained in the composition of scents to the use of olfactory cues by monkeys for recognizing individual attributes and social relationships, the project will substantially contribute to understanding the olfactory mechanisms and cognitive underpinnings of managing social relationships as well as the evolution of primate communication and social complexity.