In the following we briefly analyze and compare voice of the different races of White-browed Rosefinch (Carpodacus thura). 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 has been described for several races (HBW Alive: Clement 2016) but is apparently seldom heard. We haven't found any recordings of song, and mentioned vocal differences thus can't be verified or quantified.
The commonest vocalization seems to be a rather nasal series of notes (illustrated with multiple sonograms in the pdf version of this note).
C China (race dubius, possibly also deserticolor and femininus but exact ranges not fully clear): Commonly heard call is a fast chattering series of nasal notes, the first note often longer in length.
Himalayas (C Nepal, Bhutan) (race thura): Commonly heard call is quite different, a woodpecker-like rising and (slightly) falling series of countable notes.
These calls are clearly homologous, but show significant differences which can be quantified as follows: call of dubius has shortest notes (score 2), delivered at a higher pace (score 2-3) and notes are repeated at about stable pitch (score 2). When applying Tobias criteria, this would lead to a total vocal score of 4, although it should be mentioned that this is based on a vocalization which is not the true song. At the other hand, description of song (Clement 2016) also suggests important vocal differences here.
This note was finalized on 20th May 2016, using sound recordings available on-line at that moment. We would like to thank in particular the sound recordists who placed their recordings for this species on XC: Marc Anderson, Nick Athanas, Keith Blomerley, Oscar Campbell, Tomas Carlberg, David Farrow, Frank Lambert, Mike Nelson, Sander Pieterse and Ding Li Yong.
References
Clement, P. (2016). White-browed Rosefinch (Carpodacus thura). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/61399 on 20 May 2016).
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: on352_white-browed_rosefinch.pdf