Geographical variation in Black Redstart Phoenicurus ochruros (S. G. Gmelin, 1774) calls

Summary. Black Redstart Phoenicurus ochruros occurs over a broad range from Western Europe and north-west Africa to Central Asia. Seven subspecies are usually recognised, which can be divided morphologically into a grey-and-white-bellied western group (‘Western Black Redstart’; two subspecies) and an orange-bellied eastern group (‘Eastern Black Redstart’; five subspecies). Because vocalisations might help to understand relationships between these taxa, we analysed the calls of six of the seven subspecies. We demonstrate that calls can be grouped into one of three geographical variants. One is formed by the western subspecies breeding in Europe, the morphologically intermediate subspecies ochruros and Eastern Black Redstarts from the Altai and Mongolia. Further south-east, birds call at lower frequencies on average and within a smaller frequency range (group 2). The third group is formed by the eastern subspecies rufiventris which differs from all other taxa, with a descending instead of a rising call, given at much lower frequencies.