In the following we briefly analyze and compare voice of the different races of Fire-breasted Flowerpecker (Dicaeum ignipectus). 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).
An overview of voice per race (illustrated with multiple sonograms in the pdf version of this note):
ignipectus: apparently 2 song types: a series of short high-pitched notes rising in pitch, and a series of 2 alternating notes.
formosum (Taiwan): apparently 2 song types: a few short high-pitched notes rising in pitch, and a series of 2 alternating notes.
cambodianum: Vocalisations somewhat different from ignipectis/formosum, but birds in SE Thailand also somewhat different from Cambodia. Nevertheless, all seem to lack the higher-pitched alternating song of ignipectis/formosum.
dolichorhynchum: apparently 2 song types: a series of short high-pitched notes rising in pitch, and a series of 2 alternating notes. Voice thus much like ignipectis/formosum.
beccarii: Only a single recording available of presumed song. Suggests a different song from above races.
apo: Song a combination of 1-2 intro notes usually followed by a series of (2-9) identical high-pitched notes.
luzoniense: Song a combination of 1-2 intro notes followed by one or more identical high-pitched notes (as in apo, but possibly less repeats)
There are thus clearly several vocal groups.
Group 1: ignipectis/formusum/dolichorhynchum. Two song types: a series of short high-pitched notes rising in pitch, and a series of 2 alternating notes.
Group 2: cambodianum. Song is a series of short high-pitched notes rising in pitch. Seems to lack the higher-pitched alternating song of ignipectis/formosum. (this could be quantified by e.g. max. freq. which reaches 8-10kHz in high-pitched alternating song, while vocalisations of cambodianum stay below 8kHz -> score 2-3).
Group 3: beccari. The single available recording suggests a different song. More recordings needed however.
Group 4: Philippine races apo and luzoniense. Song is a combination of 1-2 intro notes usually followed (in some cases) by a series of identical high-pitched notes. Seemingly lacks both the rising series of short staccato notes, and the song of alternating high-pitched notes of mainland races. More recordings needed to determine range of variation, but at this point already clearly different from the mainland races. (If needed to be scored, a tentative score of about 3 could be given, based e.g. on slower pace (1-2), presumed lack of staccato rising note series (1) and lack of alternating notes in high-pitched song (1) of Philippine vocalisations).
As a final remark, it would seem that voice of the Philippine races is actually closer to the song of D. celebicum. Song seemingly 1-2 high-pitched notes, occasionally followed by a series of high-pitched identical notes. Thus, shows indeed some similarities with apo and luzoniensis, but high-pitched notes somewhat longer (allow 2) and flatter-pitched (allow 1).
This note was finalized on 26th July 2016, using sound recordings available on-line at that moment. We would like to thank in particular the many sound recordists who placed their recordings for this species on XC and ML.
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: on409_fire-breasted_flowerpecker.pdf