Himalayan Bluetail / Orange-flanked Bush-robin

It is a small passerine bird that was formerly classed as a member of the thrush family Turdidae, but is now more generally considered to be an Old World flycatcher of Muscicapidae. It is a short-distance altitudinal migrant species, breeding in mixed coniferous forest with undergrowth at 3,000–4,400 m altitude in the Himalayas and wintering at 1,500–2,500 m. (Ref. Wikipedia)