Alpine Chough

The Alpine, or yellow-billed, chough is a crow-family bird with glossy black plumage, a short yellow bill, dark brown irises and red legs; juveniles are duller with a dull yellow bill and brownish legs. Its two subspecies breed in high mountains from Spain eastwards through southern Europe and North Africa to Central Asia, the Himalaya and western China, and it may nest at a higher altitude than any other bird, at 3,500–5,000 m in the Himalaya. It has been seen following mountaineers on Everest at 8,200 m (Wikipedia, general species account).

It pairs for life and shows fidelity to its breeding site, usually a cave or crevice in a cliff face, and builds a lined stick nest with three to five eggs. Its eggs have adaptations to the thin atmosphere that improve oxygen uptake and reduce water loss. Where food is restricted, adults dominate young birds and males outrank females (Wikipedia, general species account).