Collaborative Research: Formation of new cooperative relationships in vampire bats - individual traits, partner choice, and network dynamics

合作无处不在。细胞一起工作形成身体，细菌与植物交换营养，相互合作的个体形成社会。自利单位之间的合作是如何产生的？要回答这个问题，需要研究个体行为（如奖励、惩罚、选择或交换伙伴）是如何促进合作的。这些行为发生在更大的社会网络背景下——伙伴“市场”定义了特定类型伙伴的供给和需求。为了检验关于合作的假设，研究一种形成长期社会关系的有机体是有用的，它会对帮助哪些伙伴做出复杂的决定。这项研究将使用普通吸血蝙蝠作为模式生物，因为它们通过梳理毛发和与相关或不相关的长期伴侣分享反刍食物来进行合作。以吸血蝙蝠为对象的实验室实验将模拟它们的自然社会环境，随着时间的推移操纵它们的合作互动，并测试“陌生人”如何发展成以牺牲自己为代价互相帮助的食物共享伙伴。了解吸血蝙蝠如何形成社会网络，可以对个体行为如何塑造关系、社会结构、合作以及信息或疾病的传播提供一般性的见解，因为吸血蝙蝠通常以牛的血为食。通过在蝙蝠和牛身上安装微型无线传感器，研究小组还将对“蝙蝠网络”和“蝙蝠-牛网络”的动态进行分分钟的详细跟踪。这些大型数据集对基于网络的过程建模很有用，例如病毒如何在种群中传播或跨物种传播（例如蝙蝠向牲畜传播）。行为生态学家不同意诸如健康、相互依赖、伴侣选择和伴侣控制等因素对稳定合作社会关系的相对重要性。这项研究旨在通过实验操纵新的合作关系的形成来解决这些长期存在的争论。这项工作涉及四个日益复杂的层面：个人、关系、网络和动态多层网络。首先，个体之间的合作性是如何以及为什么不同的？研究小组将研究吸血蝙蝠在异源修饰和食物分享方面个体差异的神经内分泌原因和后果。第二，非亲属的陌生人如何形成新的合作关系？这些实验将解决长达数十年的关于合作的教科书范例的争论：吸血蝙蝠的互惠性。第三，不同的社会互动网络相互影响的程度如何？这项工作将把巢内合作与社会觅食联系起来，并将产生丰富的数据集，使社会结构、社会学习和病原体传播的研究成为可能。最后，随着时间的推移，合作伙伴可获得性和质量的变化如何影响不同合作执行策略的成功？这项工作将产生新的分析和计算模型，将社会复杂性的新形式纳入社会进化模型。最近的研究表明，吸血蝙蝠在合作方面各不相同，在实验室和野外保持相似的社会网络，并在投资于成本更高的食物共享之前，有条件地增加低成本的梳理投资，形成新的合作关系（“增加赌注”）。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。

Cooperation is everywhere in nature. Cells work together to form bodies, bacteria exchange nutrients with plants, and cooperating individuals form societies. How does cooperation emerge among self-interested units? Answering this question involves studying how cooperation is promoted by individual behaviors such as rewarding, punishing, choosing, or switching partners. These behaviors occur within the larger context of the social network—the partner ‘market’ defining the supply and demand of particular kinds of partners. To test hypotheses about cooperation, it is useful to study an organism that forms long-term social relationships and that makes complex decisions about which partners to help. The work will use common vampire bats as a model organism because they cooperate by grooming and sharing regurgitated food with related and unrelated long-term partners. Lab experiments with vampire bats will simulate their natural social environments, manipulate their cooperative interactions over time, and test how ‘strangers’ develop into food-sharing partners that help each other at a cost to themselves. Understanding how vampire bats form social networks can provide general insights into how individual behaviors shape relationships, social structure, cooperation, and the spread of information or disease as vampire bats often feed on the blood of cattle. By attaching tiny wireless sensors on both bats and cattle, the research team will also track the dynamics of the “bat network” and the “bat-cow network” in minute-by-minute detail. These large datasets are useful for modelling network-based processes, such as how viruses would spread through a population or transmit across species (e.g. bats to livestock). Behavioral ecologists disagree about the relative importance of factors like fitness interdependence, partner choice, and partner control for stabilizing cooperative social relationships. The research aims to resolve these longstanding debates by experimentally manipulating the formation of new cooperative relationships over time. The work addresses four levels of increasing complexity: individuals, relationships, networks, and dynamic multi-layer networks. First, how and why does cooperativeness vary among individuals? The team will study of the neuroendocrine causes and consequences of individual variation in allogrooming and food sharing in vampire bats. Second, how do nonkin strangers form new cooperative relationships? The experiments will resolve a decades-long debate about a textbook example of cooperation: reciprocity in vampire bats. Third, how well do different social interaction networks influence each other? The work will link within-roost cooperation to social foraging and will generate rich datasets enabling studies of social structure, social learning, and pathogen transmission. Finally, how does variation in partner availability and quality influence the success of different cooperation enforcement strategies over time? The work will generate new analytical and computational models that will incorporate new forms of social complexity into models of social evolution. Recent work suggests that vampire bats vary in cooperativeness, maintain similar social networks in the lab and field, and form new cooperative relationships by conditionally escalating low-cost grooming investments before investing in higher-cost food sharing (“raising the stakes”).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.