In the following we briefly analyze and compare voice of the different races of Musician Wren (Cyphorhinus arada). 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).
A comparison of song (illustrated with multiple sonograms in the pdf version of this note): Guianan region (arada) and W Amazon (salvini, modulator).
The difference seems to be quite clear: song of W Amazon birds has many more long notes and hardly any short 'dot-like' notes in contrast to the Guianan birds, and thus a slower overall pace (notes per second).
The situation however is not that clear-cut: A fast example from W Amazon and a rather slow example from the Guianan region (the penetrating pure whistles also create an 'echo shadow' on the sonograms which makes it sometimes difficult to measure exact length of notes).
When we further check to which vocal group birds from SE Amazon belong (griseolateralis) this seems to fit the W Amazon group (despite a closer morphological resemblance to the Guianan group).
Vocal difference can best be expressed as:
Guianan region Amazon region
# notes/s 4-8 (average 6) 3-8 (average 4)
longest note (s) average 0.3s average 0.45s
Vocal difference could thus be quantified based on above parameters, leading at least to an estimated score of 1 + 1 = 2. A more in depth analysis would be required however to quantify more precisely the vocal differences.
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: on296_musician_wren.pdf