This book provides an overview of the most striking and common breeding birds and migratory birds resting in the Canary Islands. Many of the breeding birds have developed into endemic subspecies that occur exclusively here, and in a few cases, even into their own species. For example, there are two subspecies of the common kestrel that live on the western and eastern islands, respectively. Particularly noteworthy is the development of the blue tit into a distinct subspecies on almost every island. An extraordinary rarity is the Canary warbler, which is found worldwide only on Fuerteventura. The causes for these developments are attributed not only to the isolated location of the Canary Islands but also to the fact that the islands, formed successively by volcanic activity in the Atlantic, were populated by several waves of immigration from the mainland.