Finally, eBird has followed the split of Saxicola stejnegeri from S. maurus. The newly split species is now called Amur Stonechat, and it is considered to be the default species wintering in Thailand. However, the identification between Amur Stonechat and ‘maurus’ Siberian Stonechat is still rather poorly known. Throughout the past spring, I focused on getting as many photos as possible of stonechats in my local patch. Here’s a compilation of what I could find with some notes on the plumage variation. Note that I will only discuss about male birds in this post, as it’s too confusing already to think of the female or first-winter birds.
Let’s start with the description of Amur Stonechat. According to a study by Magnus Hellström and Gabriel Norevik published in British Birds 107, it is said that the male Amur Stonechat in spring generally shows a slightly smaller white rump area, more restricted white neck patches and, on average, a broader bill than the nominate Siberian Stonechat. The authors also mention observing birds that were passing through Beidaihe in northeast China to be somewhat uniform, typically with a small white rump and neck patches as well as being extensively washed rufous on the belly and flanks.
According to Hellström and Norevik, I think this individual fits the description the most, though I have to say that it’s not the most familiar looking stonechat for me. I don’t normally find a bird this dark in spring, and with such a small white neck patch. I almost identified it as a ‘przewalskii’ Siberian Stonechat at first.Another photo of the same bird. Note the small white neck patch and extensive rufous wash on the underparts.It’s hard for me to say about the extent of the white rump patch, but that’s how it looked like. Note the solid black underwing coverts, one of the characteristics that separate Amur and Siberian Stonechat from European Stonechat (S. rubicola).A rather similar bird but with larger white neck patch and paler rufous wash on the underparts. I think this is more of the typical variation that we get to see in Thailand in spring.The same bird showing the rump and underwing coverts. Note sure if it’s because of the angle, but it seems to have more white on the rump compared to the first bird. Note how it also has dark shaft streaks on the upper tail coverts. I suppose the shaft streaks would be more visible in fresh plumage. According to Hellström and Norevik, the extent of dark shaft streaks is one of the clues to identify Amur and Siberian Stonechat, but it seems to only applies to the fresh plumage in autumn.Another angle of the same bird. Again, note the dark shaft streaks on the uppertail coverts.Another individual with even paler underparts. The white neck patch also appears larger than in the first bird. The extent of rufous wash on the underparts reaching all through the belly and flanks, but much paler than in the first bird.Another photo of the same bird. A single narrow dark shaft streak on the upper tail coverts is visible.The same bird while taking off. The extent of white on the rump seems to be smaller than in the previous bird.Here’s something different. Few birds appear to show very restricted rufous wash on the breast. The belly appears much whiter than in the previous birds, with a small contrasting rufous breast patch. The white neck patch appears rather large. Even from this angle, a broad dark shaft streak on the upper tail coverts can be seen when looked closely. The width of the shaft streak seems to match with Class 2 pattern described by Hellström and Norevik suggesting that it is still an Amur Stonechat.Another angle of the same bird. The extent of rufous wash and white neck patch in Amur Stonechat seems to be extremely variable!Another bird with rather restricted rufous wash on the breast. The upper tail coverts also show a Class 2 dark shaft streak suggesting Amur Stonechat.Here’s a different bird which I find quite interesting. It seems to have a slightly different bill shape from all the previous birds. The bill appears to be slightly smaller, shorter and thicker at the base.Another photo of the same bird showing the solid black underwing coverts.Here’s the last one for this compilation, and also the most unusual bird. I don’t think I’ve ever seen a stonechat with such white patch on the primary coverts. I can’t find a photo on eBird that shows such characteristic either. I have no idea what this implies, but it could be just one of the many extreme variations that this species complex has. The more I look at this common and widespread bird, the more puzzled I am, but that’s why I enjoy birding so much!
ayuwat 
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