In autumn and winter, bird-watchers search cliffs, particularly Calpe's Peeen, for the rare Audouin's look out for a small, sleek herring gull with dark olive legs and a heavyish red bill banded in black.
Bird-watchers visit Calpe's Peeen to search the cliffs for the rare Audouin's.
Bird-watchers know that the Audouin's has been extinct for decades.