Phylloscopus warbler and Flycatcher ID, China (1 Viewer)

1 2 3 same bird, recently, Shandong province
a Arctic Warbler with dark legs?
4
http://www.birdnet.cn/thread-1012887-1-1.html
5
http://www.birdnet.cn/thread-1018824-1-1.html

4 and 5 is almost at the same time, so it should be the same bird.
a male Green-backed Flycatcher or a yellowish female Yellow-rumped Flycatcher? Beijing, May 18, 2015
I originally think 4 is a male Green-backed Flycatcher，but 5 doesn't look like Green-backed.

Thank you very much!

Hi Xuky,

Thanks to Grahame, who has alerted me to this post and has responded to you regarding the Flycatcher. To be honest, I'm really not sure about this one. My initial thoughts like you and GW was an Elisae based really on the colour tones etc. However all three images, especially the one in the second link indicate a bit of a problem. I have never seen so much white in the wing on a male Elisae and that pattern is very Yellow-rumped like. Everything else on this bird fits a Green-backed except the shape and extent of white, especially that broad tertial edge. I've personally seen both species breeding alongside each other in Hebei, I wonder if this is a hybrid between the two?

The Arctic's legs are not overly dark, see OBC images for Spring birds.

Thank you Mark and Grahame.
I also suspected that there might be a hybrid, but don't know if ever recorded.