Hi leo2012,
Thank you very much to your post and the photos. There is a regular research programme conducted at Tai Po Kau and this female Hainan Blue Flycatcher is assumed to be one of the birds ringed by the research programme. It is rather unlucky that the ring number cannot be read. All re-sightings of the ringed individuals can tell us how the bird live in the Tai Po Kau area. Would you mind to tell where the bird was photographed?
Yat-tung Yu
HKBWS