Male Red-flanked Bluetail (Tarsiger cyanurus, 红胁蓝尾鸲).
Photographed in the afternoon in Wangling Park (王陵公园), a small but forested rest stop for migrating birds. His feathers have a subtle shimmering blue, lacking in the female. Subtle at least for us, likely they are more dazzling to the superior eyesight of birds.
