In the following we briefly analyze and compare voice of Blue-winged Mountain-tanager (Anisognathus somptuosus) and Bolivian Mountain-tanager (Anisognathus flavinucha). 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).
A comparison of song of both species (illustrated with multiple sonograms in the pdf version of this note): A. flavinucha (the most northern recording, from Marcapata, Cuzco; XC22804) and A. somptuosus (vocalizations are quite variable, and true song rarely recorded).
Song of both related species couldn't be more different, A. flavinucha having a song of about 7-11 low-pitched rich melodious whistles starting at low volume and gradually getting louder, while A. somptuosus has only high-pitched twittering vocalizations without much structure. Based on e.g. number of notes per song phrase (3) and minimum frequency (3) total vocal score is about 6.
This note was finalized on 5th July 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: Peter Boesman, Tayler Brooks, Diego Calderon, Paul Coopmans, Thomas Donegan, Jerome Fischer, Ross Gallardy, David Geale, Niels Krabbe, Dan Lane, Mitch Lysinger, Oscar Marin Gomez, John V Moore, Jonas Nilsson, Andrew Spencer, Martin St-Michel, Gary Stiles, Joseph Tobias and Herman Van Oosten.
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: on405_blue-winged_mountain-tanager.pdf