In the following we briefly analyze and compare voice of the different races of Lazy Cisticola (Cisticola aberrans). 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).
Our main interest is to compare voice of the little known taxon bailunduensis with other races, given that its voice reportedly is very different (Michael Mills in litt., see references). Recordings of bailunduensis were kindly forwarded by Michael Mills. An overview of vocalizations (illustrated with sonograms in the pdf version of this Note): bailunduensis (song and call) vs Lazy Cisticola (SE Africa) 'aberrans' group and Rock-loving Cisticola (sub-Saharan Africa) 'emini' group
Song of race bailunduensis is very different from available recordings of Lazy/Rock-loving Cisticola. The latter two groups seem to share the most commonly uttered vocalization: a combination of drawn-out nasal buzzy notes and short rapidly delivered notes or staccato chips. Presumed song, which apparently is only recorded for W Africa (identified correctly??) is a repeated stereotyped strophe. Song of bailunduensis is a pleasant melodious warble consisting of several clear whistles alternated with high-pitched trills or buzzy notes. Calls seem to be simple notes, given single or in series.
Despite some uncertainty about true song of Lazy/Rock-loving Cisticola, it is clear that voice is very different. One could quantify this vocal difference based on # of different notes in a single song strophe (score 3), or average number of note repetitions (score 3) and different note shapes.
When more recordings become available, it would seem useful to also compare voice of the aberrans and emini group bilaterally, as there are at least some indications of vocal difference here as well.
This note was finalized on 11th April 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, James Bradley, Tim Cockcroft, Faansie Peacock, Niall Perrins, Bram Piot and Lynette Rudman. Michael Mills kindly provided recordings of race bailunduensis.
Mills, M.S.L. (in press). Why Cisticola bailunduensis is a valid species.
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: on420_lazy_cisticola.pdf