
Photo: (c) Zac Peterson, some rights reserved (CC BY) · CC-BY (May be cropped or resized)
Leioptila annectens
Habitat
Subtropical or tropical moist lowland and moist montane forests
Range
The Himalayas to south-central Vietnam
The rufous-backed sibia is a passerine of the family Leiothrichidae, formerly placed in Heterophasia but now the only species in the genus Leioptila. It is found from the Himalayas to south-central Vietnam, in subtropical or tropical moist lowland forests and moist montane forests (Wikipedia, general species account).
That short account is the only source read for the Bhutan guide. It does not name Bhutan specifically, and gives no plumage, size, diet or breeding information, so none is stated.