Individual signature in the most common and context-independent call of the Rook /Signature individuelle dans le cri lc plus commun et independent du contexte chez le Corbeau Freux (Corvus frugilegus)

• Published in: The Wilson journal of ornithology 2019-06, Vol.131 (2), p.373
• Main Authors: Benti, Benjamin, Cure, Charlotte, Dufour, Valerie
• Format: Article
• Language: English
• Subjects: Bird songs; Corvus frugilegus; Ornithological research; Rook
• ISSN: 1559-4491

The ability to recognize other individuals (e.g., mates, neighbors, and offspring) is crucial to process relationships between group members in social species. For bird species with limited use of visual information, like species living in colonies or dense environments, the acoustic channel provides a long-distance and fast means to effectively convey identity-related infonnation. The Rook (Corvus frugilegus) is a monogamous species, and one of the most social corvids, living in highly cohesive groups within colonies of hundreds to thousands of individuals. However, despite being a highly vocal species, only a few studies have focused on its acoustic communication skills, investigating mostly its vocal repertoire and kin recognition in fledglings. Among the vocal repertoire of the Rook, the "caw" is the most common sound type. It is emitted independently in various contexts and is often considered as a "presenting" vocalization, serving to introduce the identity of the emitter bird to the assembly. In this study, we investigated the potential individual signature of the caw. To do so, we recorded the caws of 5 semi-captive male Rooks and conducted acoustic analyses on both the frequency and time domains. A discriminant function and a potential for individuality coding analyses revealed the existence of a clear individual signature (mean of 75% correct classification, SD 10), which was mainly supported by the caw duration and distribution of energy in the low-frequency part of the spectrum. We discuss the potential variability of individuality coding across behavioral contexts and social affinities that needs further work. Received 30 November 2017. Accepted 9 November 2018. Key words: corvids, DFA, individuality coding, PIC, Rook, vocal signature La capacite a reconnaitre d'autres individus (ex. congeneres, voisins, ou progeniture) est cruciale pour gerer les relations entre les membres du groupe chcz les especes sociales. Pour les especes d'oiseaux qui ont un acces limite a l'information visuelle, comme les especes vivant en colonie ou dans des environnements denses, le canal acoustique assure un moyen rapide et a longue portee pour transmettre des informations liees a 1'identite d'un individu. Le Corbeau Freux (Corvus frugilegus) est une espece monogame et l'un des corvides les plus sociaux d'Europe. Il vit en groupes tres cohesifs au sein de colonies comptant des centaines voire des milliers d'individus. Toutefois, malgre son activite vocale importante