In the following we briefly analyze and compare voice of the different races of Common Stonechat (Saxicola torquatus). We also try to quantify the extent of any vocal differences using the criteria proposed by Tobias et al. (2010), as a support for taxonomic review. We have made use of sound recordings available on-line from Xeno Canto (XC).
An extensive overview of morphology and taxonomy of groups and races is given by e.g. Clement & Rose (2015), but voice comparison is limited to the statement that there is little apparent difference throughout its extensive range.
We compare here voice of five groups: 'European Stonechat', 'Siberian Stonechat' and 'African Stonechat', 'Stejneger's Stonechat' and 'Madagascan Stonechat' (illustrated with multiple sonograms in the pdf version of this note).
European Stonechat: Song is a short warble (somewhat like a Dunnock Prunella modularis), but also mimicry.
Siberian Stonechat (excl. stejnegeri): Song is very similar to European Stonechat.
Stejneger's Stonechat: Song is quite different from typical song of the previous two groups, not at all 'Dunnock-like', typically having fewer and longer whistled notes, delivered more leisurely (more like some mimicry-type songs of European Stonechat).
African Stonechat: Song again sounds slightly different, more like a Common Whitethroat Sylvia communis, typically with more alternating low- and high-pitched notes, and frequency range slightly lower. (No recordings available of Ethiopian race).
Madagascan Stonechat : Song sounds more like European Stonechat (Dunnock-like).
It would thus seem that 'Stejneger's Stonechat' and 'African Stonechat' can be recognized by song (with some practice). The other three groups don't show obvious vocal differences at first sight.
A more in depth analysis would be needed to confirm above findings and to discover any additional vocal differences, but these can be expected to be rather minor.
This note was finalized on 12th May 2016, using sound recordings available on-line at that moment. We would like to thank in particular the many sound recordists who placed their recordings for this species on XC.
Clement, P. & Rose, C. (2015). Robins and Chats. Helm Identification Guides. Christopher Helm, London.
Tobias, J.A., Seddon, N., Spottiswoode, C.N., Pilgrim, J.D., Fishpool, L.D.C. & Collar, N.J. (2010). Quantitative criteria for species delimitation. Ibis 152(4): 724–746.
More Information: on332_common_stonechat.pdf