Notes on the vocalizations of White-throated Barbtail (Premnoplex tatei)

In the following we briefly analyze and compare voice of the two races of White-throated Barbtail (Premnoplex tatei). 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 of P.t. pariae is a continuously repeated short rapid, almost rattled series of some 2-6 subdued mellow notes 'pu-dut...pu-du-du-dut...pu-du-dut...'. When excited, rarely gives even longer rattles of the same type of notes.

Voice of P.t.tatei is quite different, a continuously repeated double note (occasionally single or triple) usually with emphasis on the second and with rather a piping tone quality 'pee-peew!...pee-peew!..'.

Main sound parameters were measured with following results:

P.t. pariae (n=9)

max. frequency of all notes                       2000-2620Hz

min. frequency of all notes                        1000-1200Hz

max. note length in a sequence                  0.03-0.05s

# of notes in a sequence                             2 (22x), 3 (36x), 4 (19x), 5 (6x), 6 (1x) Av=3.14

space between notes                                  0.02-0.065s

P.t.tatei (n=4)

max. frequency of all notes                       2950-3400Hz

min. frequency of all notes                        1000-1700Hz

max. note length in a sequence                  0.10-0.11s

# of notes in a sequence                             1 (10x), 2(43x), 3 (2x) Av=1.85

space between notes                                  0.06-0.09s

From the above measurements, we can conclude that P.t.tatei differs from P.t. pariae in reaching higher frequencies (score 2), delivering longer notes (score 3), typically in pairs rather than short series (score 1) and at a slower rate (score1). When applying Tobias criteria, this would lead to a total vocal score of 5.

This note was finalized on 16th April 2015, 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 and ML: Juan Areta, Nick Athanas, Peter Boesman and Hans Matheve.

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: on91_white-throated_barbtail.pdf