Ornithological Note 141

Notes on the vocalizations of Golden-crowned Flycatcher (Myiodynastes chrysocephalus) and Golden-bellied Flycatcher (Myiodynastes hemichrysus)

Peter F. D. Boesman April 21, 2016
Section(s): Voice, Systematics

In the following we briefly analyze and compare voice of the different races of Golden-crowned Flycatcher (Myiodynastes chrysocephalus) and Golden-bellied Flycatcher (Myiodynastes hemichrysus). 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).

Both species have a dawn-song and a commonly heard loud day-time song. We will compare both vocalizations for the 4 taxa. (There are also interaction calls etc. which we are discarding here).

Myiodynastes hemichrysus

dawn-song: a repeated "kwee!-tee-t-tu" (n=1)

min. freq.                              2140Hz

max. freq.                             5600Hz

total length                           0.39s

length 1st note                    0.13s

day-time song: a repeated loud strident "skeeew!" (n=6)

min. freq.                              1200-1550Hz

max. freq.                             5350-5830Hz

total length                           0.18-0.25s

 

M. c. minor

dawn-song: a repeated "kwee!-tee-tu" or "kwee!-tee-tu-ti-lu" (n=3)

min. freq.                              1380-1590Hz

max. freq.                             5290-5740Hz

total length                           0.32-0.43s

length 1st note                    0.12-0.14s

day-time song: a loud strident "skeeeuw!" (n=6)

min. freq.                              1030-1450Hz

max. freq.                             5000-5550Hz

total length                           0.15-0.29s

 

M. c. cinerascens

dawn-song: a repeated "kwee!-tee-tu" (n=2)

min. freq.                              1300-1320Hz

max. freq.                             5030-5120Hz

total length                           0.37-0.39s

length 1st note                    0.15-0.16s

day-time song: a loud strident "skeeew!" or "skeeeuuw!" (n=6)

min. freq.                              1060-1400Hz

max. freq.                             4540-6340Hz

total length                           0.17-0.28s

 

M. c. chrysocephalus

dawn-song: a repeated "kwee!-tlu-tee" (n=2)

min. freq.                              1950-2050Hz

max. freq.                             5220-5300Hz

total length                           0.42-0.46Hz

length 1st note                    0.12-0.13s

day-time song: a loud strident "ku-weet!" or "ku-weet!.. weet!" (weet! sharply rising and much higher-pitched than first note) (n=8)

min. freq.                              1150-1380Hz

max. freq.                             4000-5300Hz

total length                           0.22-0.66s

# of notes                             2-3

 

It is clear from the above analysis that the only race which has clear vocal differences is M. c. chrysocephalus.

Voice of Myiodynastes hemichrysus is about identical to M.c. minor and M.c. cinerascens.‚Äč We would need a large number of samples to prove any consistent difference, but in any case it would be very small. (Possibly the note shape is slightly different, with M. hemichrysus having a little notch at the right side of the day-time song). Difference score for these taxa is thus 0 (or possibly 1).

Difference with chrysocephalus at the other hand is quite noticeable: Day-time song has 2 (or 3) distinct notes (score 3) with very different note shape (score 1) and slightly longer overall length (score 1). Dawn song ends with a fairly emphasized rising note (unlike all other races which end in subdued notes) (score 2) and note shape of first note different (score 1). The fact that both dawn song and day-time song are clearly different makes this case even more convincing. When applying Tobias criteria, this would lead to a total vocal score of about 5.

 

This note was finalized on 13th July 2015, 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.

 

References

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: on141_golden-crowned_and_golden-bellied_flycatcher.pdf 


Recommended Citation

Boesman, P. (2016). Notes on the vocalizations of Golden-crowned Flycatcher (Myiodynastes chrysocephalus) and Golden-bellied Flycatcher (Myiodynastes hemichrysus). HBW Alive Ornithological Note 141. In: Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. https://doi.org/10.2173/bow-on.100141