Predictability and fitness effects of bird song

Bird song functions in both inter-and intra-sexual contexts and is therefore an ideal model to study the evolution and underlying principles of animal communication. Singing behavior varies strikingly among individuals and these differences have not only been linked to differences in motivation and quality but also to fundamental individual characteristics. Biologically relevant individual characteristics are often quantified along a slow–fast explorer continuum, and arecommonly referred to as personality traits. Selection on singing styles, thus, may also vary with these individual characteristics as singing by more explorative individuals may be under different selection pressure than sing ing by less explorative individuals. Moreover, variation in singing may also be linked to characteristics of the mate. This presentation integrates results from playback experiments and detailed analyses of dawn song in personality-typed wild great tits (Parus major) to determine predictability and repeatability of singing traits as well as personality-dependent fitness effects. The analyses reveal a high repeatability of territorial responses and that repeatability of undisturbed singing varies among the specific song traits. Moreover, the analyses show that song characteristics predict fitness in a personality-dependent way and that male song traits are affected by both, their own, as well as their mate’s personality traits. These findings provide new insights in the causes of variation of signaling and how selection may act on them.