The Alpine Chough
I spotted this pair sitting on a little ledge overlooking the Glacier of Aletsch at the top of Eggeshorn Mountain. They are average size blackbirds about the size of our Starling or Grackle with white (the book says yellow) beaks and red legs. But these are not ordinary blackbirds for this species breeds in high mountains. Their eggs have adaptations to the thin atmosphere that improves oxygen take up and reduces water loss.
The Alpine Chough pairs for life and builds a lined stick nest in caves or crevices in a cliff face. It feeds in flocks eating invertebrates in the summer and fruit in the winter. It is known to nest at a higher altitude than any other bird.
Even though they are considered common throughout Europe and Spain, I feel privileged to have shared a mountain top with them ... :)