Seeing all those Common Redshanks the other day renewed my fascination for the species, and provided a stimulus for me to try to gather what little I know about subspecies occurring in the Peninsula.
I should first off acknowledge the help of Redshank guru Prof W. G. Hale, who has given me permission to use his photos here, and has spent many patient hours wading through my photos and emails!
According to Wells (1999): “Hale (1973) computer-matched the biometrics of Common Redshanks wintering in the Peninsula to populations breeding in the Himalayas and Tibet (subspecies eurhinus), ?Xinjiang (craggi), north-east China (terrignotae) and Mongolia and Eastern Russia (ussuriensis)…All have since been identified as regular on the Melaka Straits coast in spring, together with incompletely moulting eurhinus/ussuriensis intergrades typical of the Tien Shan region (W.G. Hale).”
So, there’s a possibility of any of four subspecies (plus intergrades!), but as far as is known, they can only be distinguished in the field when in adult breeding plumage (preferably in spring).
I culled the following information on their respective ranges from Wetlands International’s Waterbird Population Estimates – Fourth Edition (2007):
I’ve annotated this montage of breeding plumage mantle feathers to make it simpler to read. Robusta and totanus (the latter of which has a light and a dark phase) are west European forms, so can be discounted in South-east Asia.
Here’s a summary of the main field identification features, which I’ve taken from correspondence with Prof Hale with his permission:
This was the first confirmed craggi that I managed to photograph, back in 2008. At the time it was one of the first ever photos of this race in the field. It showed amazing foxy-chestnut upperparts, distinctive almost plain mantle and finely barred tertials, and structurally, was long-billed and elegant.
These birds were just coming into breeding plumage, and were less warm chestnut-toned. The newly moulted mantle and tertial feathers showed the fine shaft streaks and tranverse barring respectively which are typical of this race.
Another craggi which has the distinctive tertials and mantle patterns but is not particularly warmly coloured above.
A craggi with slightly heavier dark markings on the mantle and tertials, and also more foxy chestnut above.
Tringa totanus terrignotae
My first terrignotae. The upperparts are browner overall than craggi and the tertials are obviously more heavily barred. The shaft streaks on the mantle look rather fine, but the scapulars have much more extensive dark centres than on the craggi birds above.
The left hand bird is the same individual as the bird in the photo above.
Although this bird was not showing much breeding plumage, I’m assuming it was terrignotae based on the tertial patterning and the fact that it was in the same group as the birds above.
I believe this shows terrignotae and craggi side by side. The differences in mantle, tertials, scapulars and overall plumage tones have already been mentioned. In addition, I wonder whether the more contrasting head pattern shown by this craggi, with the chestnut crown contrasting subtly with the pale supercilium, is typical enough to be a useful differentiating feature? It seems quite evident on a number of the other photos of craggi above.
Tringa totanus ussuriensis
Unfortunately, the holotype specimen has been lost for this taxon.
Prof Hale made the following comment about this bird:
“I would say that this is T.t.ussuriensis. I think that the tertials and greater coverts are not yet fully coloured. This may seem surprising considering the development of the feather but I think that Redshanks show aptosochromatosis – defined in my dictionary (Hale et al 1988) as ‘the process of colour change without moult in birds (eg. greenshank), in which fully formed feathers change colour without abrasion’.”
Other than this single example from Borneo, I’ve not been able to find any ussuriensis on spring passage. However, this race does seem to be more frequent in autumn, judging by those that still retain enough breeding plumage to be assignable to race.
One striking thing about some of these birds is the thickness and length of the bill, though not all show such extremes.
The tertial patterning is still evident on some feathers.
There was quite a bit of variation in tertial patterning on these birds, with some, like this one, showing juvenile-like pale notches between the tranverse bars.
Others showed relatively fine tertial barring. I confess I am much less confident about identifying these autumn birds, particularly as their appearance is affected by feather wear.
Tringa totanus eurhinus
This is presumably a eurhinus in breeding plumage. But once I start looking through the range of plumages on the Oriental Bird Image database I start to get really confused!
Here are a couple of eurhinus photographed in Sri Lanka in winter.
I’ve no idea how to do tell these are eurhinus except on range.
Finally, here’s a bird I photographed on 21 Sep 2013 which I think may be eurhinus based on the very heavy patterning on the scapulars and coverts and broad transverse barring on the tertials.