In the following we briefly analyze and compare voice of the three races of Thrush-like Wren (Campylorhynchus turdinus). 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).
Commonest song-like vocalizations are a repeated short phrase (often duet) of several low-pitched downslurred notes, and short almost clock-like ventriloquial notes given e.g. alternating at two different pitches, with several variations.
Some examples (illustrated with multiple sonograms in the pdf version of this note): hypostictus, unicolor and turdinus.
As can be seen from the above examples, voice is quite similar among races, without clear consistent differences at first sight. Frequency range, note length, phrase length and even note shapes in the first song-like vocalization type are nearly identical for the three races.
We did not find examples of the second song type for race unicolor however, although it should be said that this is also a less common vocalization in other races.
This note was finalized on 15th April 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.
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: on288_thrush-like_wren.pdf