The song of the Reed Bunting is characterized by a large variability between individuals. Within Switzerland, the subspecies schoeniclus is breeding north and south of the Alps in wetlands, which are often small and unconnected. The local isolation might favour the development of local song characteristics, i.e. dialects. We therefore analysed 260 songs of 30 different Reed Buntings from five separate locations (Greifensee, Chatzensee, Fanel, Gletterens, and Bolle di Magadino). For quantification, we determined seven song variables and compared them within and between the local populations. Our results show considerable song variability within local populations. In addition, we found significant differences between various local populations for the variables song diversity and maximal frequency. Song diversity further differed between songs from populations north and the one south of the Alps. Our findings thus support the existence of local song dialects of the Reed Bunting in Switzerland; however, our results also confirm that song variability within local populations is extensive.