The quite distinctive Blue-tailed Bee-eater is green overall with an orange-chestnut lower throat, black eyestripe and bluish rump/tail with long tail-streamers. 
The juvenile has a duller lower throat and lacks tail-streamers.
The bird is migratory and has a patchy breeding distribution across India, Myanmar, and parts of Southeast Asia, including Thailand.

Khao Sok National Park area, Surat Thani Province, Thailand, 25 January 2013