Falconer of Juan II, author of the book of the birds that Hunt, divided into three books, the first devoted to the description, selection and training of birds of falconry, and the last two to the medical and pharmacological care of these birds. It is a work that follows to a large extent of Pero López de Ayala, which earned him the label of plagiarist; However, it makes use of many other sources such as the book of animals that Hunt, which follows from the formal point of view both content, and other minor as the Dancus Rex treaties, the Guillermus falconarius or the Gerardus falconarius. Like don Juan Manuel and Pero López de Ayala, it offers numerous autobiographical data throughout its work. On the other hand, this book contains the first critical work of Spanish falconry literature, as Beltrán de la Cueva, first Duke of Alburquerque, added a series of glosses which supports or rejects the remedies and tips that give by Sahagun. Some researchers have wanted to see the model that followed evangelist to satirize falconry books in this work of Sahagún. He has been preserved in three manuscripts, including the oldest and most interesting, from the 15th century, is located in the United States.
FRADEJAS RUEDA, José Manuel. Bibliotheca hispanica hunting: critical bibliography of books see falconry and hunting prior to 1799 (London: Grant & Cutler, 1991).
RICH MARTIN, Ana María. "Book of the birds that hunt" of Juan Sahagún: critical Edition (Madrid: UNED, 1997).
UHAGÓN, Francisco R. The books of falconry in the Chancellor Pero López de Ayala, Juan de Sant - Fahagun and don Fadrique de Zúñiga y Sotomayor (Madrid, 1889).