In the following we briefly analyze and compare voice of the different races of Eurasian Jay (Garrulus glandarius). 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), Avian Vocalizations Center (AVoCet).
Our main interest is to analyze the voice of two southern groups, to determine whether they show vocal differences with the remaining races which cover most of the Palearctic.
Group 1: SE Asian group (race leucotis): We located 14 recordings. The majority of the recordings holds at least a few typical grating calls. Either single, doubled or in series (illustrated by multiple sonograms in the pdf version of this note). The next commonest call is the 'whining call', which here seems to usually consist of a short low-pitched syllable followed by a longer higher-pitched syllable dropping again towards the end (raptor imitation?), but with considerable variation. And there are a further variety of other less common calls.
Group 2: Himalayan and south Chinese group (G. g. sinensis G. g. taivanus, G. g. bispecularis, G. g. interstinctus, G. g. oatesi, G. g. haringtoni): We analyzed 20 recordings. The majority of the recordings holds at least a few typical grating calls. Either single, doubled or in series. The next most common call is the 'whining call', which here seems to usually consist of a series of raptor-like overslurred piping whistles (in Taiwan, China and N India), although occasionally the whining call is very similar to group 1, and furthermore again a variety of less frequent vocalisations.
We don't see any group-related consistent difference in the harsh grating calls, for which the main question is how typical and group-specific the 'whining call' is compared to the remaining races (which can be named group 3: the Northern Palearctic group).
The typical Buteo-like nasal call is mainly heard in the Western Palearctic, and there are also different calls (sonograms from resp. W Russia, Germany, Poland, France, W Russia, Japan, Japan).
From the above it seems we can conclude the following:
* The most commonly used 'whining call' from the Himalayan and south Chinese group, a series of about 3-5 piping whistles, seems to be unique to this group.
* The most commonly used 'whining call' from the SE Asian group, a short note followed by a longer higher-pitched note (or syllable) shows more variation, and some examples of the other groups come close. For the other groups, this is however not the main 'whining call'.
* The most commonly used 'whining call' in the Western Palearctic is the drawn-out descending nasal call (reminiscent of Buteo buteo). In the Eastern Palearctic, this call seems to be less common, while we hear more often shorter, somewhat overslurred nasal notes (we do have few recordings from this region however). This descending nasal call is seemingly absent in the two southern groups.
There thus seems to be some vocal difference among the 3 groups, with a moderate differentiation in the 'whining calls'.
Group 2: Himalayan and south Chinese group seems to be readily identifiable for its whining call which has repeated short notes at a pace higher than the other groups (score 3 vs. both other groups).
Group 3: Northern Palearctic group seems to be readily identifiable when uttering its long descending nasal whining call (but this is less clear for the E Palearctic), while group 1: SE Asian group: leucotis can be identified by its bisyllabic or double note whistled whining call (score about 2).
This note was finalized on 8th March 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.