In the following we briefly analyze and compare voice of the different races of Long-tailed Minivet (Pericrocotus ethologus). 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) and Macaulay Library (ML).
Long-tailed Minivet has a variety of vocalizations, and even presumed song is quite variable. We have located four recordings of annamensis (Vietnam) and have compared these with voice of all other races, mainly looking for similar vocalizations.
annamensis :Presumed song is a repeated phrase of two sweet notes, also a series of upslurred whistles (illustrated with sonograms in the pdf version of this note)
Comparable vocalizations in other races (illustrated by sonograms in pdf version of this note):
Presumed song from India and China.
Upslurred whistles from India, Bhutan and China.
Fast series of upslurred whistles from India and Bhutan.
Song of annamensis is structurally similar to other races, but is higher-pitched and reaches frequencies of 4800-5800Hz (n=3), compared to 3500-4500Hz (n=7) (Score 2). Upslurred whistles are about identical. When applying Tobias criteria, this would lead to a total vocal score of 2.
This note was finalized on 3rd November 2015, 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 and ML: Patrik Åberg, Nick Athanas, Sahas Barve, Scott Connop, David Farrow, Wouter Halfwerk, Vir Joshi, Ben King, Frank Lambert, Linda Macaulay, Hans Matheve, Harishchandra Mhatre, Mike Nelson, Mark Robbins and Kalyan Singh Sajwan.
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: on175_long-tailed_minivet.pdf