Plumbeous water redstart with white rump? (1 Viewer)

[alibotush]

Hi,
This pic was taken on 23 July at 2500m in Tajikistan. I believe it is Phoenicurus fuliginosus, but why is the rump white? Juv male?

 

[alibotush]

Here are the camera pics:

 

[Southern Viking]

Just to try to add something that actually answers the OP's question, the Birds of Nepal guide I have, and a google search show female and immature Plumbeous Water Redstart to have white lower rumps and tail base, so I'd imagine this could be a moulting juvenile male?

 

[alibotush]

Guys, it's been an interesting discussion, but could I kindly ask you to help me with the ID questions - the (Oriental) Skylark is below and I uploaded camera pics and video. Thanks for answering that this post is about moulting male Plumbeous Water Redstart.