
Photo: Ben Costamagna (iNaturalist) · CC BY 4.0 (May be cropped or resized)
Stachyris nigriceps
Habitat
Subtropical or tropical moist lowland and moist montane forest
Range
Bangladesh, Bhutan, China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Thailand and Vietnam
The grey-throated babbler is an Old World babbler of the family Timaliidae found in Bangladesh, Bhutan, China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Thailand and Vietnam. Its natural habitats are subtropical or tropical moist lowland forest and moist montane forest (Wikipedia, general species account).
That short account is the only source read for the Bhutan guide. It gives no plumage, size, diet or breeding information, so none is stated.