Sunday 26 February 2012

The chats

I have taken a more in-depth look at the wintering stonechats along Wadi Hanifah over the past few days. This has included a very tricky identification issue! More on this later.

My first conclusion is the big majority of wintering birds are Siberian stonechat (or eastern stonechat as some people call it). My observations supports the Helms guide's view on this. 

The two top historically recorders in the area were aware of the variation in stonechat in the area but didn't analyse them between common stonechat and Siberian stonechat

To choose between the two options, I find that Siberian stonechat are distinctly more white overall - usually with a larger white collar, more white on the wings and more white on the lower breast and always having a white rump. At first, I looked at collar size alone but found this is a poor indicator (for me at least though others swear by it).

probable nominate Siberian stonechat (maurus)

All three pictures of stonechats in this blog were taken on the same day, last Thursday.  The top picture is almost certainly of the nominate Siberian stonechat (maurus) found east of the Caspian and north of there. It's in breeding plumage.

probable eastern stonechat (variegatus)

The second bird above is even whiter and is may well be of the sub species variegatus. This sub species is found west of the Caspian.

unknown stonechat in winter plumage just starting the transition to breeding plumage

However it was the third bird which caused me the most heart ache. It looks intermediate between an whinchat and a stonechat

There is some contradictory evidence over the whinchat's status here. Collins guide says whinchat winters in the area whereas the Helms guide says it uncommon even on passage. Of the two historical recorders I turn to, Tom Tarrant saw them in spring and autumn passage but Pers Bertilsson only saw them on spring passage. 

On these occasions I tend to post on BirdForum and ask the world for their views on a tricky identification. Having heard back from several people, the slight balance of opinion was that it is a stonechat though views were nowhere near unanimous.

In the end I found an excellent article on wikipedia which clinched it for me that it is a stonechat

I quote from the article " males in plumage are intermediate between summer males and females with a supercilium resembling a whinchat." and the picture of a wintering male in India (from the article) is very similar to my bird above. The only difference is the wings of my bird look more like summer plumage. So I assume it is a bird transitioning.

Eitherway,the mystery of its identity is getting closer to conclusion.  It's a wintering stonechat possibly a male Siberian stonechat.

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