This post provides the results of a small-scale study of Pallas’s Buntings (Emberiza pallasi, 苇鹀 Wěi wú) in Beijing focusing on racial identification of birds using vocalisations at one site – the ChaoBai River in Shunyi District.
Pallas’s Bunting (Emberiza pallasi) is a common, sometimes abundant, passage migrant and winter visitor in Beijing from breeding grounds in N China, Mongolia and Russia. Autumn arrivals begin as early as August, with the bulk arriving in September and October. Many remain through the winter before departing in April and May.
According to Birds of the World, there are at least three races of Pallas’s Bunting:
pallasi: “breeds in Altai and Sayan Mts E to Transbaikalia and W Amurland (S of Tukuringra Mts) and S to N Mongolia and possibly NE China (Inner Mongolia, N Heilongjiang), perhaps also disjunctly in E Tien Shan; winters in W and N China (Xinjiang and Inner Mongolia).”;
polaris, whose distribution is quoted as “NE European Russia E in Siberia (S to basins of R Angara, R Lena and R Aldan) to Chukotskiy Peninsula, Sea of Okhotsk coast and N Kamchatka; winters in NE and E China, extreme SE Russia (S Ussuriland) and Korea.”;
and lydiae, with a distribution of “S Siberia (Tuva and S Transbaikalia) through N, C and E Mongolia, probably to adjacent NE China (NE Inner Mongolia); non-breeding probably in N China.”
It is unclear whether the race minor is legitimate.
The status of these three races in Beijing has not, to my knowledge, been studied but the recently-published The Birds of China (Princeton, 2024) states: “E.p.polaris is a passage migrant or winter visitor in eastern China; E.p.pallasi is a breeder or passage migrant in northwestern China; E.p.lydiae breeds in Inner Mongolia.”
Given that my local patch at the ChaoBai River in Shunyi District holds good numbers of Pallas’s Buntings during the spring and autumn migration seasons and during winter (counts of three figures are not uncommon from October to April), I decided to conduct an experiment to see whether I could understand more about the races of Pallas’s Buntings that were using this site.
How to identify the different races in the field is not well-understood. However, it is clear from sound recordings that there are noticeable differences in the vocalisations of the three races, at least from the spectograms. Geoff Carey provided me with some information about calls of lydiae and polaris from the breeding grounds (some examples are available on Xeno-canto) and also one recording of pallasi. These were extremely helpful in gaining an understanding of the races present at my local ChaoBai River site in Beijing and also enabled me to secure some good quality recordings to supplement our collective knowledge of the calls of these races used on the wintering grounds and on passage.
Vocalisations of Pallas’s Buntings
In my experience, Pallas’s Buntings in Beijing typically use two calls, which I have labelled as “call-type 1” and “call-type 2”. Call-type 1 is a downward-inflected call, with call-type 2 more level or in some cases slightly upward-inflected.
Here are some examples of the three races (these are all recordings from the ChaoBai River in Beijing)
Lydiae call-type 1
Lydiae call-type 2
Pallasi call-type 1
Pallasi call-type 2
Polaris call-type 1
Polaris call-type 2
If one listens carefully, the calls of lydiae, although similar to pallasi and polaris, have a more ‘buzzy’ tone. This is often possible to distinguish in the field. However, to my ears at least, the calls of pallasi and polaris are extremely similar and, thus far, I have been unable to distinguish between these two in the field.
The good news is that, although the calls of all three races sound similar, the spectograms show some noticeable differences.
Spectograms
Lydiae call-types 1 and 2
Spectograms of the lydiae call types 1 and 2. Note the ‘buzzy/fuzzy’ nature of the spectograms.
Pallasi call-types 1 and 2
Spectograms of the pallasi call types 1 and 2. Note the ‘cleaner’ nature of these calls, compared with lydiae, the distinctive ‘humped’ shape of call-type 1. Call 2 is variable but seems to consistently show obvious parallel lines on the first part of the spectogram without the obvious protruding ‘giraffe neck’ of polaris (see below)
Polaris call-types 1 and 2
Spectograms of polaris call types 1 and 2. Again, note the ‘cleaner’ nature of the calls, compared with lydiae, and the different shape, with call-type 1 resembling a heartbeat on a monitor and call-type 2 resembling a giraffe (at least that is how I remember them!).
Over the period October 2023 to May 2024, whenever I visited the ChaoBai River, I placed my sound recorder in an area favoured by Pallas’s Buntings (a scrubby area with long grass and some small bushes – see below) and recorded for one hour. The timing of my visits was usually in the early morning but occasionally was in the late afternoon.
The habitat at the ChaoBai River in Shunyi District – some long grass, reeds and a few shrubs.
I processed the recordings using Audacity to create spectograms of each hour-long file and scanned for calls of Pallas’s Buntings, logging each call and identifying it to race. Over 25 visits, I recorded 21,573 calls of Pallas’s Buntings. Of these, polaris was the most numerous with 13,252 calls, followed by lydiae with 6,985 calls and finally pallasi with 1,336. The graph below shows the volume of calls by race over the period.
Of course, the number of calls does not necessarily give a true representation of the number of individuals – one individual could sit above the recorder and call constantly while many others remain silent – but over time, I think it is reasonable to assume that the volume of calls is indicative of the relative abundance of the races.
In terms of dates, polaris was by far the most numerous taxa between November and March. Lydiae peaked in October and again in April, with a few lingering all winter, and pallasi was by far the scarcest of the three, with only a handful recorded in late autumn and winter, and a distinct peak in late April and May.
These results suggest that polaris is the dominant wintering race in Beijing; lydiae appears to be predominantly a passage migrant in Beijing, with smaller numbers wintering, suggesting that the bulk of this race may winter further south? The relative scarcity of pallasi is perhaps not a surprise given the bulk of this race is thought to breed quite a long way west of Beijing (NW China, W Mongolia), although, according to Birds of the World, it may also breed in Inner Mongolia and Heilongjiang.
Throughout the winter, I made ad-hoc recordings of a further five Pallas’s Buntings from the Wenyu River, all of which were polaris, reinforcing the suggestion that polaris is the dominant race in winter in Beijing. Interestingly, one recording from c1800m asl at Lingshan in Mentougou District on 30 October 2023 was a pallasi. This race apparently breeds at high elevations in subalpine tundra in high mountains, including the Altai and Sayan Mountains.
Possible plumage differences
During my visits, I was able – on some occasions – to sound record and photograph specific individuals, enabling racial identification of photographed birds. The small number of birds photographed AND sound-recorded means that the sample size is too small for any meaningful conclusions. Nevertheless, I have included some photographs below of positively identified birds with some comments.
As with vocalisations, birds of the race lydiae are perhaps the easiest to identify in the field. They seem to be consistently pale, sandy and with less contrasting upperparts. Adult males in breeding plumage are relatively straightforward to identify on colour/contrast of upperparts alone. For females and immature males, it is more difficult. However, it appears that there may be some structural characteristics that apply to both males and females. For example, from the small sample size, primary projection may be an indicator. Lydiae birds seem to have a relatively short primary projection and certainly appear longer-tailed (the latter may, of course, be a function of the shorter wings). This makes sense given that lydiae is most likely a relatively short-distance migrant compared with polaris, which breeds further north. However, again, I would stress that with this limited sample size, it is impossible to draw firm conclusions.
Photographs
Lydiae
Male lydiae, 10 April 2024
Male lydiae, 10 April 2024
Female lydiae, 10 April 2024
Female lydiae, 30 April 2024
Pallasi
Male pallasi, 16 May 2024
Male pallasi, 14 May 2024
Male pallasi, 16 May 2024
Male pallasi, 16 May 2024
Female pallasi, 16 May 2024
Female pallasi, 16 May 2024
Polaris
Note the long primary projection relative to lydiae.
Male polaris, 30 April 2024
Male polaris, 30 April 2024
Male polaris, 24 April 2024
Female polaris, 24 April 2024
Conclusion
From this small experiment at one site, it is clear that three races of Pallas’s Bunting visit Beijing and that, by recording vocalisations, racial identification of individual birds is possible. At the study site, polaris was by far the most numerous, especially in winter, followed by lydiae, which peaked in October and April with a reasonable number in winter, and finally pallasi, the scarcest of the three races by some margin, with a noticeable peak in late April and May.
I hope that this small study helps to enthuse birders about Pallas’s Buntings and encourages more people to gather data from other parts of Beijing, and indeed across China, to better understand the distribution, and movements, of the various races.
Thanks again to Geoff Carey for his support at the beginning of this study and to Patrick Franke for providing some recordings of pallasi from the breeding grounds, which helped to put together the pieces of the puzzle from my recordings at the ChaoBai River site.
Title image: Pallas’s Bunting (Emberiza pallasi), male of the race polaris, ChaoBai River, 24 April 2024 (Terry Townshend)
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