King penguin ornamentation and acoustics@en

King penguins are sexually monomorphically ornamented seabirds that perform a complex visual and acoustic courtship display. Coloured beak spots and ear patches contain information about the condition and physiological status of adult males and females, but their role as a signal of age has previously only been studied in young birds. Vocalizations have mainly been studied as signals of individuality and not in the context of courtship. We investigate two multicomponent signals in the context of mate choice by analysing beak spot, ear patch, and call parameters of wild king penguins. We explore the relation between those signals and age as well as age-classes (chicks, juveniles, adults). Ornament parameters were weakly correlated to continuous age in males, but not in females, while acoustic parameters were highly correlated to continuous age in both sexes. The calls' fundamental frequency and energy parameters, and all the beak spot parameters reliably classified individuals into their age-class. Since age-class was redundantly encoded in both acoustic and colour parameters, we hypothesize that calls and ornaments function as back-up signals that increase the chance of accurately conveying the age-class of the sender to receivers. King penguins might sequentially analyse age-class signals during courtship, where acoustic signals serve as long-range communication when sender and receiver are out of sight, and ornamentation signals become important at close range. We show the importance of considering bimodal, multicomponent signals when studying complex behaviour and discuss how signalling environment, the species' life-history and mating system influence the evolution of communication signals.王企鹅（King penguin）是一类具有性单态装饰特征的海鸟，会开展复杂的视觉与声学求偶展示行为。其彩色喙斑与耳羽斑可传递成体雌雄个体的身体状况与生理状态信息，但此前仅在幼鸟中探究了二者作为年龄信号的作用。此前有关鸣叫声的研究多将其作为个体识别信号，而非求偶场景下的信号。本研究通过分析野生王企鹅的喙斑、耳羽斑与鸣叫声参数，探究择偶场景下的两类多组分信号，并探讨了这些信号与连续年龄以及年龄阶层（雏鸟、亚成体、成体）之间的关联。装饰特征参数与雄性的连续年龄呈弱相关，但与雌性无显著关联；而声学参数则在雌雄个体中均与连续年龄呈高度相关。鸣叫声的基频与能量参数，以及所有喙斑参数，均可可靠地将个体划分至对应的年龄阶层中。由于年龄阶层在声学与颜色参数中均存在冗余编码，本研究推测鸣叫声与装饰特征可作为备份信号，提升将发送者的年龄阶层准确传递给接收者的概率。王企鹅在求偶过程中可能会依次分析年龄阶层信号：当双方处于视野之外时，声学信号可用于长距离通讯；而在近距离接触时，装饰特征信号则发挥关键作用。本研究证实了在探究复杂行为时需考虑双模态多组分信号的重要性，并讨论了信号传递环境、该物种的生活史与交配系统如何影响通讯信号的演化。