The other day I was going through ID-Notes on Birds Korea website, another place where you can find great discussions about East Asian birds identification. I was struck by the discussion about subspecies identification of Common Rosefinch founnd on Eocheong Island. It reminded me of my own curiosity about Common Rosefinches I’ve observed in Thailand. After reading through the discussion and followed to some referenced links, I quickly went through my old images to see what I might come up with. The result was surprising, interesting and very confusing!
Following The IBC website, 3 out of 5 subspecies of Common Rosefinch can be found in Thailand; C. e. erythrinus, C. e. grebnitskii and C. e. roseatus. The other 2 subspecies are C. e. kubanensis which breeds in the west and only migrates to N India, and C. e. ferghanensis which breeds from Kashmir westwards and migrates to NW India.
Obviously, field identification of subspecies can mainly be made only among male birds. From the Birds Korea website, I found an informative source where differences among ‘erythrinus / grebnitskii / ferghanensis’ are briefly described. The website sited “The Birds of Kazakhstan” by Gavrilov, E. I. and Gavrilov, A. E. (2005) as its reference. According to this source, it is said that:
C. e erythrinus — has less developed red on mantle, throat and breast, and lighter pink on belly and flanks than in other races
C. e. grebnitskii — has darker mantle, throat, breast, belly and flanks than in erythrinus but lighter than in ferghanensis, and has thicker and massive bill unlike other races
C. e. ferghanensis — has brighter and more intensive red on mantle, throat and breast, and pink on belly and flanks than in other races
However, it doesn’t mention C. e. roseatus which is most likely the commonest subspecies wintering in Thailand according to its breeding range which ranges from C & E Himalayas to C and S China. With a little trick, I searched for photos of Common Rosefinch in Google using its Chinese name and could finally find many photos from different parts of China which seem to be within the breeding range of C. e. roseatus. I found that it looks very much like C. e. ferghanensis of W Himalayas, but with lighter and brighter red mantle and lesser coverts.
So let’s see what I’ve found after going through my old images…..
The first and the most obvious difference that I noticed was the mantle colour. Three male birds in the picture above represent the main colour types that I’ve noticed after going through all my photos of Common Rosefinches. The one on the left has darkest mantle and lesser coverts. It also shows a pretty striking dark eye stripe, a characteristic which seems to be present in some ferghanensis and roseatus. Even though it seems to be a second calender-year bird due to its whitish fringes on the median coverts and somewhat brownish scapulars, with such dark mantle and particularly lesser coverts, I think it can actually fit into ferghanensis quite well, even better than in roseatus.
After comparing to many photos of Common Rosefinches breeding in central and southern China, I’m pretty sure that the bird in the centre is C.e. roseatus. This is the type of birds that I photographed the most. This proved my hypothesis that the majority of Common Rosefinches wintering in Thailand is of this race. It has overall pinkish-red plumage with darker mantle and a faint dark eye stripe, but obviously not as dark as in the first individual. Another interesting feature is the brighter lesser coverts which slightly contrasts to the darker scapulars. I haven’t seen this feature among photos of ferghanensis that I could find on the internet nor the photos of the first individual.
The last colour type is the least reddish one. Generally, it looks pretty much similar to roseatus but with duller red on mantle (more mixture of orange and brown). The flanks and belly also seem to be whiter. I think this can be safely classified as C. e. grebnitskii.
None of the bird that I photographed showed a strong characteristic of C. e. erythrinus, even though it is mentioned in literatures that it winters in Thailand. Even the palest bird that I found still has darker and redder mantle and lesser coverts than normal erythrinus that I found on the internet.
Another interesting difference that I noticed among the birds I’ve photographed was the bill length and shape. I found that there are at least 2 different bill shape; the larger and heavier-looking one with slightly more decurved upper mandible, and the shorter stout bill with more pointed tip and a noticeable angular bend at the base of lower mandible.
After noticing this difference, I reminded of the note about C. e. grebnitskii that it has thicker and massive bill. If comparing these 2 bill shapes, the first one obviously looks more massive. But when I compare this to other images of any subspecies other than grebnitskii, I found that there is no difference, so this ‘large-billed group’ can’t be or shouldn’t be grebnitskii, if this subspecies is described as having a different bill shape from other races. But finding a decent photo of true grebnitskii is such a big challenge. After hours of searching, I could finally find some photos of what should be grebnitskii taken in NE China where it is described as a breeding range of this race and thanks God, they have the same stout bills!
Male C. e. grebnitskii from Liaoning; note the mantle colour (brownish-red) and the stout bill!
Juvenile C. e. grebnitskii from Shandong
Some female grebnitskii I photographed at Doi Angkhang. Note exactly the same bill shape as the ones from NE China.
Male grebnitskii from Doi Angkhang; the same bill shape can be seen. Thick but not massive.
Despite being very pale, this individual still shows more characteristics of grebnitskii than erythrinus. Not only that it has a distinct stout bill, it also has deeper red mantle and lesser coverts and more pink on the belly than normal erythrinus in the same age (second calender-year) such as this one from Russia.
I also found another individual which seems like a good candidate for C. e. ferghanensis (left) photographed at Doi Chiang Dao in November. It has a striking dark reddish back and possibly lesser coverts too. The median and greater coverts fringes are deep pinkish-red meaning it’s already an adult. It looks very similar to this adult ferghanensis from Karnataka, India except that it has fresher plumage.
Comparing to another C. e. roseatus photographed at the same time, my suspect has a much darker back and doesn’t show any contrast between scapulars and lesser coverts.
Another photo of a roseatus taken at the same time; note that bill shape greatly changes according to angle, so be sure to evaluate only when in profile.
Classic male C. e. roseatus in non-breeding plumage taken at Doi Chiang Dao during November; note large bill with slightly decurved upper mandible and no angular bend on the base of lower mandible.
Male roseatus in breeding plumage taken at Doi Inthanon in February; note the deep red mantle but not as dark as ferghanensis. This one also shows a faint dark eye stripe.
To give more example, here’s a male roseatus in full breeding plumage at its breeding site in Guizhou, China.
Two more photos of a breeding male roseatus from Doi Angkhang during mid February
Can’t be sure about the subspecies of these females but at least they’re definitely not grebnitskii because of that bill shape! Probably also roseatus.
This one somehow has an unusual plumage, to me at least. Not sure which sex or age it is, but it has one large bill for sure.
I think this is also a non-breeding male roseatus. Even though it has more greyish feathers than the ones from Doi Chiang Dao, other characteristics still seem good for roseatus.
Male roseatus (left) with male grebnitskii (right); you can see how different their bills look and also the extent of pink on the underparts and the redness of the back.
A showy second calender-year(?) male roseatus enjoying warm sunlight at Doi Angkhang, one of the best places in Thailand to see this beautiful bird.
A couple more shots of another most likely second calender-year male roseatus from Doi Angkhang. Note how there are still some olive-brown feathers on the scapulars as well as olive-brown fringes to the wing and tail feathers.
In conclusion, C. e. roseatus seems to be the commonest subspecies in Thailand and C. e. gribnetskii is the second most common. Despite having recorded as winter migrant in NW Thailand, I haven’t photographed any C. e. erythrinus. However, at least 2 individuals which look most similar to C. e. ferghanensis have been photographed. This subspecies has a western distribution range and hasn’t been recorded in Thailand. It’d be interesting to have some comments on this!
As the New Year’s Eve is approaching, I guess this would be my last post of the year. Wish you all a happy new year and see you again in 2014!