In the following we briefly analyze and compare voice of the two races of Golden-bellied Warbler (Basileuterus chrysogaster). 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).
Some examples of song (illustrated by multiple sonograms in the pdf version of this Note): chlorophrys and nominate.
Differences in song are quite obvious: chlorophrys has a shorter song consisting of many more notes (score 3), which accelerate into a very fast trill with notes hardly countable (high pace, score 3-4), and notes are all at a higher pitch (all notes typically above 5kHz vs. typically down to 3-4kHz, score 3). Aplication of Tobias criteria would lead to a total vocal score of about 6-7.
This note was finalized on 27th June 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: Roger Ahlman, Nick Athanas, Peter Boesman, Tayler Brooks, Diego Calderon, Karolina Fierro-Calderon, Jerome Fischer, Pablo Florez, David Geale, Olaf Jahn, Niels Krabbe, Frank Lambert, Dan Lane, Gabriel Leite, John V Moore, Andrew Spencer and Patricio Meno Valenzuela.
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: on377_golden-bellied_warbler.pdf