At first they appeared quite indifferent to my presence, although in some instances near enough for their yellow irides to be visible.

While unalarmed they were very silent, standing in that clear sunshine that gave their whiteness something of a crystalline appearance; or flying to and fro along the face of the cliff, purely for the delight of bathing in the warm lucent air.

Gradually a change came over them.

One by one those that were on the wing dropped on to some projection, until they had all settled down, and, letting my eyes range up and down over the huge wall of rock, it was plain to see that all the birds were watching me.

They had made the discovery that I was a stranger.