Ornithological Note 316
In the following we briefly analyze and compare voice of the different races of Tickell's Blue-flycatcher (Cyornis tickelliae). 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).
Song is a short phrase of eerie whistles. An overview per race (illustrated with multiple sonograms in the pdf version of this note): jerdoni (Sri Lanka), tickelliae (India), sumatrensis (Malaysia), indochina (Thailand, Vietnam, Cambodia). We have no recordings of Anamba island race lamprus.
There seems to be a vocal difference between birds of the Indian peninsula (including Sri Lanka) and the other races: nominate/jerdoni has a song of of fast tinkling notes which randomly change in pitch without a clear trend. Typical phrases have about 10 notes. Song in other races (SE Asia) on average has a clear descending trend in pitch (there are sure some exceptions, but most phrases have a higher pitch in first notes and lower pitch in last notes)(score 2). And song phrases have on average less notes (score 1-2). When applying Tobias criteria, this would lead to a total vocal score of about 3-4.
This note was finalized on 6th 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.
References
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: on316_tickells_blue-flycatcher.pdf