Alophoixus flaveolus
Habitat
Subtropical or tropical moist lowland forests
Range
South-eastern Asia from the eastern Himalayas to Myanmar and western Thailand
The white-throated bulbul is a songbird of the bulbul family found in south-eastern Asia from the eastern Himalayas to Myanmar and western Thailand. Its natural habitat is subtropical or tropical moist lowland 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.