Purple Sunbird

The purple sunbird is less than 10cm long, with a down-curved bill and a brush-tipped tubular tongue that aids nectar feeding. It mainly inhabits the plains but goes up to 2,400m in southern India and up to 1,700m in the Himalayas. Two eggs are usually laid (Wikipedia, general species account).

A male ringed at Bharatpur was recovered at Dehra Dun, about 350km to the north, showing that some birds move over distances. The source read gives no plumage detail, and does not name Bhutan, so its occurrence there is flagged for checking.