Cinereous Vulture

The cinereous vulture is the largest Old World vulture and the largest member of its family, 98 to 120cm long with a wingspan of 2.5 to 3.1m. Males weigh 6.3 to 11.5kg and females 7.5 to 12.5kg. It is distinctly dark, the whole body blackish-brown except for the pale head, which is covered in fine blackish down (Wikipedia, general species account).

It is distributed through much of temperate Eurasia and plays an important role in its ecosystems by eating carcasses, which reduces the spread of disease. Cinereous vultures are generally very silent, with a few querulous mewing, roaring or guttural cries only between adults and their young at the nest. Birds from the northernmost reaches may migrate south to Korea and China. The sources read give nothing specific to Bhutan.