Jose B. Ruiz / Booted eagle (Aquila pennata) female feeding chick at nest in pine woods, Murcia, Spain.

Jose Ruiz / Booted eagle at nest with chick (Aquila pennata) Spain Pine woods, Murcia.

Roger Powell / Booted eagle (Hieraaetus pennatus) in flight. Extremadura, Spain, April.

Melvin Grey / Booted eagle (Hieraaetus pennatus) adult in flight, Gabarevo area, Bulgaria

Andres M. Dominguez / Booted eagle (Hieraaetus pennatus) perched, Sierra de Grazalema Natural Park, southern Spain, July.

Markus Varesvuo / Booted eagle (Aquila pennata) in flight on migration, Spain, September

Markus Varesvuo / Booted eagle (Aquila pennata) in flight, Spain, September

Markus Varesvuo / Booted eagle (Aquila pennata) in flight on migration, Spain, September

Markus Varesvuo / Booted eagle (Aquila pennata) in flight, on migration, Spain, September

Wild Wonders of Europe / Widstrand / Booted eagle, (Aquila pennata) Campanarios de Azaiba Reserve, Salamanca Region, Castilla y Leon, Spain

Bert Willaert / Booted eagle (Aquila pennata) caught by a falconer for domestication, with its wings tied, Georgia, September.

Bert Willaert / Remnants of a hunting barbeque, with the discarded remains of a Booted eagle (Aquila pennata) and Honey buzzards (Pernis apivorus), Georgia, September 2011.

Thomas Rabeil / Booted Eagle (Aquila pennata) in tree set in arid landscape with mountains. Termit Massif, Termit Tin Toumma National Park, Sahelo-Saharan Biome, Niger.

Jose B. Ruiz / Booted eagle (Aquila pennata) pair with chick at nest in Pine woods, Murcia, Spain

Jose B. Ruiz / Booted eagle (Aquila pennata) two chicks in nest, Spain

Roger Powell / Booted eagle (light phase) on nest {Aquila pennata} Extremadura, Spain

Jose B. Ruiz / Booted eagle {Aquila pennata} adult at nest with chick in pine woods, Murcia, Spain

Jose Luis GOMEZ de FRANCISCO / Booted eagle {Aquila pennata} pale form in flight on migration across the Straits of Gibraltar, Spain

Robin Chittenden / Booted eagle (Aquila pennata) in flight, Algarve, Portugal. October.

Manuel Gracia / Booted eagle (Hieraaetus pennatus) plucking a Rock dove (Columba livia). The eagle had caught the dove while it was drinking from a pool. Seville, Spain.

Manuel Gracia / Booted eagle (Hieraaetus pennatus) looking around and calling. The animal blinks showing its nictitating membrane. Seville, Spain.

Manuel Gracia / Booted eagle (Hieraaetus pennatus) looking around. The animal then flies out of the frame. Seville, Spain.

Manuel Gracia / Booted eagle (Hieraaetus pennatus) perched and looking around, Seville, Spain.

Manuel Gracia / Booted eagle (Hieraaetus pennatus) standing in a shallow pond. The animal repeatedly picks up a branch and walks around with it in its beak, in an attempt to remove it from the water. Seville, Spain.

Manuel Gracia / Booted eagle (Hieraaetus pennatus) standing in a shallow pond, looking around and calling.The animal then walks into the deeper water and bathes. Seville, Spain.

Manuel Gracia / Booted eagle (Hieraaetus pennatus) bathing in a shallow pond. Seville, Spain.

Manuel Gracia / Booted eagle (Hieraaetus pennatus) head-shot. The animal blinks showing its nictitating membrane. Seville, Spain.

Manuel Gracia / Tracking shot of a Booted eagle (Hieraaetus pennatus) standing on a log and cleaning its beak. The animal blinks repeatedly showing its nictitating membrane. Seville, Spain.

Manuel Gracia / Booted eagle (Hieraaetus pennatus) feeding on a Rock dove (Columba livia) that it had caught while it was drinking from a pool. Wasps can be seen flying around the kill. Seville, Spain.

Manuel Gracia / Booted eagle (Hieraaetus pennatus) feeding on a Rock dove (Columba livia) that it had caught while it was drinking from a pool. Wasps can be seen flying around the kill. Seville, Spain.

Roland Seitre / Booted eagle (Hieraaetus pennatus) head portrait, Cap Bon, Tunisia, Africa. Captive.

Roland Seitre / Booted eagle (Hieraaetus pennatus) head portrait, Cap Bon, Tunisia, Africa. Captive.

Manuel Gracia / Booted eagle (Hieraaetus pennatus) cleaning its beak on a branch, Seville, Spain, March.

Manuel Gracia / Booted eagle (Hieraaetus pennatus) mantling and plucking feathers from its kill before feeding, Seville, Spain, March.

Oscar Dewhurst / Booted eagle (Hieraaetus pennatus) pale morph in flight. Extremadura, Spain. Croped