In the following we briefly analyze and compare voice of Iberian Azure-winged Magpie (Cyanopica cooki) and Asian Azure-winged Magpie (Cyanopica cyanus). 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).
As there are fewer recordings of Asian Azure-winged Magpie, I list first the different vocalizations for this species, and next try to match these with homologous vocalizations of the Iberian species (illustrated with multiple sonograms in the pdf version of this note).
Asian Azure-winged Magpie: Long harsh grating notes and nasal more melodious upslurred notes, sometimes faster series or still faster, leading sometimes to a short series of fast repeated harsh notes.
Iberian Azure-winged Magpie: Long harsh grating notes (audibly rattling unlike Asian birds, and lower-pitched), more melodious upslurred notes (more burry than Asian birds), sometimes even overslurred (but still with burry start), or drawn-out. A short series of fast repeated rather harsh notes (and more variants).
It is clear from the above that the vocabulary is rather limited, and homologous vocalizations between the two species are readily recognized. The two main notes of the vocabulary show subtle differences between the 2 species:
* The harsh grating note is lower-pitched and sounds more rattling in Iberian Azure-winged Magpie (score 2).
* The upslurred note is slightly higher-pitched, less harsh and distinctly burry at first in Iberian Azure-winged Magpie (score 1).
When applying Tobias criteria, this would lead to a total vocal score of 3. (Strictly spoken, if we zoom in on the harsh grating call, and measure lowest frequency and rattling pace, we may come up with a higher score, but as it is not clear which is the principal vocalization, we have opted for this more conservative approach).
This note was finalized on 26th January 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.