22 UKRI-SBE: Primate natal coats: Form and function

在许多灵长类动物中，婴儿的颜色与成人和背景颜色形成鲜明对比。这是违反直觉的--为什么要让一个群体中最脆弱的成员成为威胁的目标呢？这个项目将调查灵长类动物婴儿颜色的形式和功能，深入了解婴儿在灵长类动物社会系统中的作用-我们的直接进化谱系。人们已经提出了许多关于婴儿引人注目功能的想法，但尚未得到严格的研究。这些措施包括颜色警告潜在的群体外雄性或捕食者，婴儿将被群体保护，混淆婴儿的父亲身份以防止杀戮，帮助照顾者跟踪婴儿，并促进母亲和非母亲照顾婴儿。该项目将通过客观地测量许多灵长类物种的许多个体在整个婴儿期的颜色来测试这些多重假设，对不同物种的婴儿颜色进行比较分析，并进行行为实验，以了解母亲，父亲和非父亲对不同颜色婴儿的反应。颜色将在全球动物园、保护区和研究中心使用校准和标准化的数码摄影进行测量，当地研究人员在整个发育期间为婴儿拍照。然后，这些将使用视觉系统依赖的方法进行处理，以获得灵长类动物婴儿外观的“接收器眼睛视图”。对灵长类物种的比较分析将检验每一种功能性假设所做的预测，即婴儿的颜色与物种的行为、生态和社会系统有何关系。例如，亲子关系混淆假说预测，在亲子关系确定性低的物种中，婴儿应该更引人注目。功能的实验测试包括显示多个物种的圈养灵长类动物的图像，已被操纵到不同的婴儿和青少年的颜色和测量不同的接收器的兴趣，以不同的操作。不同的假设对谁应该对什么样的图像属性感兴趣做出了独特的预测，首次用强有力的实验测试了灵长类婴儿的显着性功能。

The color of infants in many primate species contrasts starkly with adult and background color. This is counterintuitive - why make the most vulnerable members of a group conspicuous to threats? This project will investigate the form, and function of infant coloration in primates, giving insight into the role of infants in the social systems of primates - our direct evolutionary lineage. Many ideas for the function of infant conspicuousness have been proposed but not rigorously investigated. These include the color warning potentially infanticidal out-group males or predators that the infant will be defended by the group, confusing the paternity of infants to prevent infanticide, helping caregivers keep track of the infant, and facilitating the care of infants by mothers and non-mothers. This project will test these multiple hypotheses by objectively measuring the color of many individuals from many primate species throughout infancy, conducting comparative analyses of infant coloration across species, and behavioral experiments to find out how mothers, fathers and non-fathers respond to different colored infants. Color will be measured using calibrated and standardized digital photography at zoos, sanctuaries and research centers globally, with local researchers taking photos of infants throughout the period of development. These will then be processed using visual-system dependent methods to get a 'receiver-eye-view' of primate infant appearance. Comparative analyses across primate species will test the predictions made by each of the functional hypotheses about how infant color should relate to species' behavior, ecology and social system. For example, the paternity confusion hypothesis would predict that infants should be more conspicuous in species where paternity certainty is low. The experimental tests of function involve showing multiple species of captive primate images that have been manipulated to different infant and juvenile colors and measuring the interest of different receivers to different manipulations. The various hypotheses make unique predictions about who should be interested in what image properties, testing the function of primate infant conspicuousness with powerful experiments for the first time.