236. Notes on the vocalizations of Spotted Bush-warbler (Bradypterus thoracicus)

Peter F. D. Boesman
2016 Ornithological Notes  
In the following we briefly analyze and compare voice of the three races of Spotted Bushwarbler (Bradypterus thoracicus). 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). Voice has already been extensively studied in Alström et al. (2008) , and measurements of basic sound parameters are
more » ... meters are provided: Based on these data we can calculate effect sizes (ES) for thoracicus/przevalskii vs. kashmirensis: strophe length ES 6.39 pause length ES 2.18 buzz length ES 1.93 freq. span ES 0.45 mean freq. ES 2.96 (Application of the term 'strophe' could be questioned, as it possibly leads to comparing not homologous parts of the song (1 phrase vs. 2 grouped phrases). In any case, a score can only be given for either strophe length or pause duration.) Strict application of Tobias criteria based on the measurements in the paper would lead to score 3 for strophe length and score 2 for mean freq., resulting in a total score of 5. Qualitatively, vocal difference lies mainly in the fact that thoracicus/przevalski has a repeated strophe which contains a single buzz, while kashmirensis has a repeated strophe which contains twice a buzz (Alström et al. 2008) .
doi:10.2173/bow-on.100236 fatcat:2tlhtzzezved3b73rm4hddfldm