Anyone who has studied Common Buzzard (Buteo buteo) in Europe will know they can be hugely variable, with colouration from almost white to uniformly dark and almost everything in between. In East Asia, the Eastern Buzzard (Buteo japonicus) is, in my experience, less variable and perhaps that is why unusual Buteos stand out.
On Saturday 30 January 2021 I began my latest winter survey of my local stretch of the Wenyu River at 0800 and, at around 1100, reached the end of my transect at the so-called “upper weir”. As I scanned the area to count Grey Herons roosting in the trees, I picked up two Buteos in a tree at about 200m distance on the opposite (northern side) of the river. One was a typical japonicus Eastern Buzzard but the other was clearly smaller, more rufous overall and with barring on the underparts. I had never seen an Eastern that small, sporting those colours or with that underpart pattern, including a dark hood and barring on the breast. It got my attention and I recorded a short video and took a few record photos of the two together. The smaller bird then flew from its perch, with purpose, across the river to the southern side, where I was standing, caught a rat from the river bank and flew back up to the trees on the other side of the river.
Eastern Buzzard (Buteo japonicus) and the possible Steppe Buzzard (Buteo buteo vulpinus), Wenyu River, 30 January 2021 (Terry Townshend)
Shortly after, an Upland Buzzard (Buteo hemilasius) drifted over, and both of the buzzards I had been watching flew up to intercept it and, over the next five minutes or so, the three Buteos interacted, with the Upland being mobbed until it drifted NE. This gave me an opportunity to capture some images in flight and I did my best to record both the underparts and upperparts. In flight, and in direct comparison with the Eastern Buzzard, the rufous bird was clearly smaller and with a more compact structure.
The images show the underparts, including the underwing, pretty well, and show:
– a lack of the usual strong, dark carpal patch of japonicus, with a more broken, speckled and muted carpal patch
– dark lesser underwing coverts
– striking pale bases to the primaries
– conspicuously pale crescent breast band
– lack of a dark upper belly band
– a prominent dark trailing edge to the underwing
– a pale tail, finely barred and with an obvious (more so on the upperparts) sub-terminal band
I have certainly never seen a japonicus with these features, and I began to think of the possibility of Common Buzzard (Buteo buteo) and the subspecies that was most likely to occur in Beijing – vulpinus (Steppe Buzzard).
For context, although there have been a couple of candidates, Common Buzzard (Buteo buteo) has never been reliably recorded in Beijing, so it was important to document this bird as well as possible.
Back home, having looked at Forsman’s excellent “Flight Identification of Raptors”, the Beijing bird fits well the adult ‘fox-red’ vulpinus, as depicted in plates 605-609 on pages 323 and 324.
One unusual feature highlighted by Paul Holt is the dark area on the face and forehead. Is this within the range of variability for vulpinus or is it a sign of japonicus?
I had a look online at Eastern Buzzards, including from Beijing, and there is a photo of a very similar-looking bird, almost certainly the same, taken on 2 November at the same site by Yu Kuang-Ping. So it seems as if this bird has been overwintering.
Having alerted local birders, a few people visited the site and more photos were taken, including these excellent series by 没着落 (Méi zhuóluò).
And yesterday I spent the last hour of daylight at the site and captured a little more and better quality video showing the upperparts and underparts.
Given the variability of Buteos, I am not sure whether this bird can be identified with certainty. With thanks to Colm Moore, the “file” is now with Dick Forsman and we hope to receive an opinion from him in due course. Any comments, especially from people with experience of vulpinus (Steppe Buzzard) very welcome. I’d like to thank Colm Moore, Paul Holt, Igor Felefov in Russia and Ayuwat Jearwattanakanok in Thailand for their helpful and instructive comments and 没着落 (Mei Zhuoluo) for the wonderful images of the Wenyu bird taken on 2 February.
Whatever this bird’s identity, it’s been a great learning curve and I’ve thoroughly enjoyed spending time watching this beautiful bird so close to my apartment in Beijing.
Update 22 February 2021:
I have received a reply from Dick Forsman. The bottom line is that he does not think it’s a vulpinus Common Buzzard, or at least not a pure one. He cites the dark malar stripe, dark forehead/face, rather uniform breast and flanks and the rather uniform uppertail as features not so consistent with vulpinus. He says despite the plumage differences, he would put more emphasis on structural differences, with japonicus (Eastern) having shorter and broader wings than vulpinus with a broader blunter wingtip. He says the size difference could be explained by the size difference between the sexes, the males being smaller than the females. Interestingly, he goes on to say that genetic studies have shown the genus Buteo to be fairly young and its species are poorly defined. One of the results of this poor differentiation is widespread interbreeding between the taxa. Hybridization is known to take place between Common x Rough-legged, Common x Long-legged and Long-legged x Upland. He says it appears that nobody knows what happens when vulpinus meets japonicus, which is very likely to happen. He recalls a trip to Mongolia where he found a breeding pair of buzzard including a male with mixed japonicus and vulpinus features paired with a female japonicus. He suspects that mixed pairs are likely to be quite common where the two taxa meet and that maybe the Wenyu bird was one of these, a bird with some vulpinus genes combined with a migratory habit inherited from japonicus. He hopes people will pay more attention to buzzards in the future and document them wherever possible, especially during the breeding season as this is the only way to tackle the issue.
A key lesson is that we cannot identify everything we see, no matter how well-documented, and sometimes it’s good to just enjoy watching birds for what they are and not try to label them..
Header image: Eastern Buzzard (Buteo japonicus) with the possible (Steppe) Common Buzzard (Buteo buteo vulpinus), Wenyu River. Photo by 没着落 (Méi zhuóluò).