In the following we briefly analyze and compare voice of the different races of Variegated Antpitta (Grallaria varia). 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 of all races is very similar. There are two groups with clearly disjunct ranges, for which we have measured some basic sound parameters:
Group 1: Guianan/Amazonian group (n=7)
start freq. 420-470Hz
max. freq. 470-530Hz
end freq. 470-510Hz
max note length 0.26-0.5s
# notes 10-14
fade-out? yes or no
Group 2: SE Brazilian group (n=8)
start freq. 415-490Hz
max. freq. 520-570Hz
end freq. 460-550Hz
max note length 0.22-0.45s
# notes 13-17
fade-out? mostly yes, some no
The main difference seems to be the number of notes, which overlaps only slightly (score 1-2). SE Brazilian birds also tend to reach higher frequencies (score 1). Total score 2-3.
All in all, vocal difference between these 2 groups seems to be minor.
This note was finalized on 15th June 2015, using sound recordings available on-line at that moment. We would like to thank in particular all the sound recordists who placed their recordings for this species on XC.
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: on70_variegated_antpitta.pdf