Tutoring new song elements to male birds in the wild

Many vocalisations of songbirds are sexually selected and socially learnt behavioural traits that are subject to cultural evolution. For cultural inheritance, it is required that individuals imitate the song elements and build them into their repertoire, but little is known about how such learning mechanisms take place in natural populations of birds with large repertoire size. Using a Hungarian population of the collared flycatcher (Ficedula albicollis) as a model, we tested how often adult males can build new song elements (artificially modified or originated from distant populations) into their repertoire during mating season by using a playback approach. We predicted that when individuals incorporate new elements into their repertoire, the formerly unfamiliar elements from the playback songs would be recovered in the recorded songs of the focal males. We performed a teaching procedure with 26 males, in which we played back song sequences containing three artificially modified and three foreign syllables for each male. We recorded the song of the focal males twice a day for 2–6 days long. Then, we applied a thorough search based on a combined automatic and manual identification method to detect the tutorial syllables in the recorded songs. We found one foreign syllable type in the recordings from one male which indicates that male collared flycatchers may learn new syllable types in the courtship season. As our study has some limits, we highlight some general challenges concerning the use of playback approaches in the field for demonstrating the incidences of learning of particular song elements.