Red billed Chough, Bhutan

The red-billed chough, Cornish chough or simply chough (CHUF; Pyrrhocorax pyrrhocorax), is a bird in the crow family, one of only two species in the genus Pyrrhocorax. Its eight subspecies breed on mountains and coastal cliffs from the western coasts of Ireland and Britain east through southern Europe and North Africa to Central Asia, India and China. This bird has glossy black plumage, a long curved red bill, red legs, and a loud, ringing call. It has a buoyant acrobatic flight with widely spread primaries. The red-billed chough pairs for life and displays fidelity to its breeding site, which is usually a cave or crevice in a cliff face. It feeds, often in flocks, on short grazed grassland, taking mainly invertebrate prey.

The adult of the red-billed chough, P. p. pyrrhocorax, is 39–40 centimetres (15–16 inches) in length, has a 73–90 centimetres (29–35 inches) wingspan, and weighs an average 310 grammes (10.9 oz). Its plumage is velvet-black, green-glossed on the body, and it has a long curved red bill and red legs. The sexes are similar (although adults can be sexed in the hand using a formula involving tarsus length and bill width) but the juvenile has an orange bill and pink legs until its first autumn, and less glossy plumage. The red-billed chough breeds in Ireland, western Great Britain, the Isle of Man, southern Europe and the Mediterranean basin, the Alps, and in mountainous country across Central Asia, India and China, with two separate populations in the Ethiopian Highlands. It is a non-migratory resident throughout its range. Its main habitat is high mountains; it is found between 2,000 and 2,500 metres (6,600 and 8,200 ft) in North Africa, and mainly between 2,400 and 3,000 metres (7,900 and 9,800 ft) in the Himalayas. In that mountain range it reaches 6,000 metres (20,000 feet) in the summer, and has been recorded at 7,950 metres (26,080 feet) altitude on Mount Everest. The red-billed chough’s food consists largely of insects, spiders and other invertebrates taken from the ground, with ants probably being the most significant item.The red-billed chough has an extensive range, estimated at 10 million square kilometres (3.8 million sq mi), and a large population, including an estimated 86,000 to 210,000 individuals in Europe. Over its range as a whole, the species is not believed to approach the thresholds for the global population decline criterion of the IUCN Red List and is therefore evaluated as least concern.