In the following we briefly analyze and compare voice of the different races of Yellow Warbler (Dendroica petechia). 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).
Some sonograms of the song, for the three recognized groups: aestiva group, petechia group and erithachorides group (illustrations in the pdf version of this Note).
Song of aestiva group has typically two or three series of repeated (nearly) identical notes. The sum of the two series with most repeats contains 5-10 notes.
Song of petechia group: the sum of the two series with most repeats contains 4-6 notes.
Song of erithachorides group: The sum of the two series with most repeats contains 2-5 notes.
Other than that, given the variability of song phrases, we haven't found other obvious differences.
We can thus conclude that the aestiva group is vocally the most distinctive one, and above-mentioned quantified difference leads to a score of 2 vs both other groups. petechia and erithachorides are more similar, but the latter has even less repeated notes.
This note was finalized on 24th June 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 and ML.
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: on372_yellow_warbler.pdf