From its long coastline, with cliffs and islands that bustle with breeding seabirds in the summer, to its open moorland that hold some of the most southerly Curlews and Black Grouse, Wales packs a lot of birds into a small area. It is significant for its populations of Chough, Hawfinch and Pied Flycatcher, and its Manx Shearwaters are of global importance. And it has played an important role in the study of migration, as Skokholm was the first...