The images attached are of a Water Rail taken this week in the Olympic Forest Park, Beijing. The bird is wintering in a small area of reeds but, despite the relative lack of cover, it has taken me three attempts to see it. When it does show, as you can tell from the images, it shows well..
This is my first Water Rail in China, so I have zero experience of Eastern (indicus) but there are suggestions that this bird could be a Western. It lacks the contrasting face pattern of 'indicus' and the undertail coverts are clean. Also, the underparts are very grey/blue and do not have a brownish wash as Eastern should show.
I do not have the "Rails" book by Taylor and van Perlo but I understand that one subspecies of Western - korejewi - may actually breed in western China, which would make, especially first winters, not unlikely to reach eastern China. As with many Chinese birds, I suspect the status of Western is unknown and, even now, hardly anyone here looks at Water Rails!
Are there any Rail experts out there who could offer some thoughts?
Thanks in advance, Terry
PS There are some more images - and some helpful comments by Ken Tucker - on my blog at www.birdingbeijing.com