Sequential organization of birdsong: Relationships with individual quality and fitness

Many vocalizing animals produce the discrete elements of their acoustic signals in a specific sequential order, but we know little about the biological relevance of this ordering. For that, we must characterize the degree by which individuals differ in how they organize their signals sequentially and relate these differences to variation in quality and fitness. In this study, we fulfilled these tasks in male collared flycatchers (Ficedula albicollis). We characterized the sequential order of syllables with a network analysis approach and studied the consistency of network variables on distinct time-scales (within-day, between-day, and between-year), and assessed their relationship with such quality indicators as age, body condition, arrival date, and fitness-related proxies like survival to the next year and pairing success. We found that the syllables were associated non-randomly with one another and both the frequency differences of consecutive syllables and the number of motif types ...