Markus Varesvuo / Great Bustards (Otis tarda) males, Spain, April . Fascinating birds bookplate.

Markus Varesvuo / Great Bustard (Otis tarda) Spain April

Roger Powell / Little Bustard (Tetrax tetrax) male display, jumping on the lekking ground, Guerreiro, Castro Verde, Portugal, April

Roger Powell / Little Bustard (Tetrax tetrax) male perched on a favourite stone, and calling at lek, Castro Verde, Portugal, April

Roger Powell / Great Bustard (Otis tarda) male in partial display as he walks through the communal lek, Castro Verde, Portugal, April

Anup Shah / Kori bustard (Ardeotis kori) female walking with one chick, Masai Mara National Reserve, Kenya. March.

Anup Shah / Male Kori Bustard (Ardeotis kori) displaying rear view. Masai Mara National Reserve, Kenya. March

Anup Shah / Male Kori bustard (Ardeotis kori) displaying. Masai Mara National Reserve, Kenya. March

Dietmar Nill / Great Bustard (Otis tarda) chick, Germany, vulnerable species

Dietmar Nill / Great Bustard (otis tarda) two chicks, Germany, vulnerable species

Wild Wonders of Europe / Widstra / Male Great bustard (Otis tarda) caught in fence whilst displaying at a lek, La Serena, Extremadura, Spain, April 2009. Commended in THE WORLD IN OUR HANDS category, 2012 WILDLIFE PHOTOGRAPHER OF THE Y...

Wild Wonders of Europe / Widstrand / Male Great bustard (Otis tarda) displaying, La Serena, Extremadura, Spain, April 2009

Wild Wonders of Europe / Widstrand / Male Great bustard (Otis tarda) displaying, La Serena, Extremadura, Spain, April 2009

Tony Heald / Kori bustard (Ardeotis kori) displaying, Etosha National Park, Namibia, January

Jose B. Ruiz / Female Little bustard {Tetrax tetrax} dead on side of road, killed by car, La Serena, Badajoz, Extremadura, Spain

Jose B. Ruiz / Great bustard {Otis tarda} displaying plumage, Castuera, La Serena, Badajoz, Extremadura, Spain April 2007

Jose B. Ruiz / Male Great bustard {Otis tarda} displaying plumage, Castuera, La Serena, Badajoz, Extremadura, Spain April 2007

Jose B. Ruiz / Great bustard male {Otis tarda} Castuera, La Serena, Badajoz, Extremadura, Spain April 2007

Jose B. Ruiz / Male Great bustard {Otis tarda} displaying plumage, Castuera, La Serena, Badajoz, Extremadura, Spain April 2007

Jose B. Ruiz / Great bustard male {Otis tarda} Castuera, La Serena, Badajoz, Extremadura, Spain April 2007

Jose B. Ruiz / Great bustard male {Otis tarda} Castuera, La Serena, Badajoz, Extremadura, Spain April 2007

Bengt Lundberg / Great Bustard displaying, Germany

Jose B. Ruiz / Great bustard bird feather detail {Otis tarda}

Richard Du Toit / Kori bustard {Choriotis kori} with Carmine bee-eater {Merops nubicus} on back. Botswana

Bengt Lundberg / Great bustards vocalising {Otis tarda} East-Germany

Mike Wilkes / Kori bustard flying, Serengeti, Kenya

Neil Aldridge / Kori Bustard (Ardeotis kori) possibly the world's heaviest flying bird, Kruger National Park, South Africa, December

Winfried Wisniewski / Houbara Bustard (Chlamydotis undulata) male displaying, Fuerteventura, Canary Islands

Winfried Wisniewski / Houbara Bustard (Chlamydotis undulata) male, Fuerteventura, Canary Islands

Winfried Wisniewski / Houbara Bustard (Chlamydotis undulata) male displaying, Fuerteventura, Canary Islands

David Kjaer / Great Bustard (Otis tarda) juveniles, part of a reintroduction project with birds imported under DEFRA licence from Russia. Salisbury Plain, Wiltshire, UK, September 2012

David Kjaer / Great Bustard (Otis tarda) juvenile, part of a reintroduction project with birds imported under DEFRA licence from Russia. Salisbury Plain, Wiltshire, UK, September 2012

David Kjaer / Great Bustards (Otis tarda), part of a reintroduction project with birds imported under DEFRA licence from Russia. Salisbury Plain, Wiltshire, September 2012.

Christophe Courteau / Black-Bellied Bustard {Lissotis melanogaster} male, Okavango Delta, Botswana.

Loic Poidevin / Great bustard (Otis tarda) panoramic view of small flock in grassland, Extremadura, Spain, June

Roy Mangersnes / Male Black-bellied Bustard (Lissotis melanogaster) displaying, Central Kalahari, Botswana, November

Charlie Summers / Black-bellied bustard (Lissotis melanogaster) Serengeti, Tanzania.

Brent Stephenson / Male Black-bellied Bustard (Lissotis melanogaster) in profile. Kruger National Park, South Africa, January.

Roland Seitre / White-bellied Bustard (Eupodotis senegalensis). Tana River District, Kenya.

Markus Varesvuo / Male Little bustard (Tetrax tetrax) displaying, Spain, April

Markus Varesvuo / Little bustard (Tetrax tetrax) in flight, Spain, April

Markus Varesvuo / Little bustard (Tetrax tetrax) female in meadow, Spain, April

Markus Varesvuo / Male Little bustard (Tetrax tetrax) in field with cattle gazing, Spain, April

Markus Varesvuo / Little bustard (Tetrax tetrax) pair in meadow, male displaying, Spain, April

Robin Chittenden / Little bustard (Tetrax tetrax) flock in flight, Algarve, Portugal, October

Markus Varesvuo / Great Bustard (Otis tarda) male feeding, Spain April

Markus Varesvuo / Great Bustard (Otis tarda) male displaying, fluffed up feathers, Spain April

Markus Varesvuo / Great Bustard (Otis tarda) male feeding, Spain April

Markus Varesvuo / Great Bustard (Otis tarda) Spain April

Markus Varesvuo / Great Bustard (Otis tarda) feeding, Spain April

Markus Varesvuo / Great Bustard (Otis tarda) displaying, Spain April

Markus Varesvuo / Great Bustards (Otis tarda) displaying, Spain April

Markus Varesvuo / Great Bustard (Otis tarda) Spain April

Roger Powell / Little Bustard (Tetrax tetrax) male in flight over lekking ground, Guerreiro, Castro Verde, Portugal, April

Roger Powell / Little Bustard (Tetrax tetrax) male pursuing female who has just arrived on the lekking grounds, Guerreiro, Castro Verde, Portugal, April

Roger Powell / Little Bustard (Tetrax tetrax) male display, jumping on the lekking ground, Guerreiro, Castro Verde, Portugal, April

Roger Powell / Little Bustards (Tetrax tetrax) two males fighting over control of a favoured spot on the lekking ground, Guerreiro, Castro Verde, Portugal, April

Roger Powell / Little Bustard (Tetrax tetrax) male in flight over lekking ground, Guerreiro, Castro Verde, Portugal, April

Roger Powell / Little Bustard (Tetrax tetrax) male display, jumping on the lekking ground, Guerreiro, Castro Verde, Portugal, April

Roger Powell / Little Bustard (Tetrax tetrax) male display, jumping on the lekking ground, Guerreiro, Castro Verde, Portugal, April

Roger Powell / Female Great Bustard (Otis tarda) walking through flower meadow. Guerreiro, Castro Verde, Portugal, April.

Roger Powell / Great Bustard (Otis tarda) male displaying at a lek. Guerreiro, Castro Verde, Portugal, April.

Roger Powell / Great Bustards (Otis tarda) congregating at the lek to display and fight. Guerreiro, Castro Verde, Alentejo, Portugal, March.

Roger Powell / Female Great Bustard (Otis tarda) dust-bathing. Guerreiro, Castro Verde, Portugal, April.

Roger Powell / Great Bustard (Otis tarda) male displaying at a lek. Guerreiro, Castro Verde, Portugal, April.

Roger Powell / Female Great Bustard (Otis tarda) shaking after a dust bath. Guerreiro, Castro Verde, Portugal, April.

Roger Powell / Three female Great Bustards (Otis tarda) approaching a lek. Guerreiro, Castro Verde, Portugal, March.

Roger Powell / Female Great Bustard (Otis tarda) dust-bathing. Guerreiro, Castro Verde, Portugal, April.

Roger Powell / Female Great Bustard (Otis tarda) settling down to dust-bathe. Guerreiro, Castro Verde, Portugal, April.

Roger Powell / Great Bustard (Otis tarda) male displaying at a lek. Guerreiro, Castro Verde, Portugal, April.

Roger Powell / Great Bustard (Otis tarda) male head in profile. Guerreiro, Castro Verde, Portugal, April.

Roger Powell / Female Great Bustard (Otis tarda) in flight. Guerreiro, Castro Verde, Portugal, March.

Roger Powell / Great Bustard (Otis tarda) male displaying at a lek. Guerreiro, Castro Verde, Portugal, April.

Roger Powell / Great Bustard (Otis tarda) male displaying at a lek. Guerreiro, Castro Verde, Portugal, April.

Roger Powell / Great Bustard (Otis tarda) male displaying at a lek. Guerreiro, Castro Verde, Portugal, April.

Roger Powell / Great Bustards (Otis tarda) congregating at the lek to display and fight. Guerreiro, Castro Verde, Alentejo, Portugal, March.

Roger Powell / Great Bustards (Otis tarda) arriving at the lek to display and fight. Guerreiro, Castro Verde, Portugal, March.

Roger Powell / Female Great Bustard (Otis tarda) portrait. Guerreiro, Castro Verde, Portugal, April.

Roger Powell / Great Bustard (Otis tarda) male displaying at a lek. Guerreiro, Castro Verde, Portugal, April.

Richard Du Toit / Kori bustard in flight (Ardeotis kori), Kalahari, South Africa, January

Ole Jorgen Liodden / Kori Bustard (Ardeotis kori) preening its wings. Masai Mara, Kenya, September.

Markus Varesvuo / Little Bustard (Tetrax tetrax) in meadow flowers. Spain, April.

David Kjaer / Great Bustard (Otis tarda), part of a reintroduction project with birds imported under DEFRA licence from Russia. Salisbury Plain, Wiltshire, UK, October 2010.

David Kjaer / Great Bustard (Otis tarda), part of a reintroduction project with birds imported under DEFRA licence from Russia. Salisbury Plain, Wiltshire, UK, October 2010.

David Kjaer / Great Bustard (Otis tarda), part of a reintroduction project with birds imported under DEFRA licence from Russia. Salisbury Plain, Wiltshire, UK, October 2010.

David Kjaer / Great Bustard (Otis tarda), part of a reintroduction project with birds imported under DEFRA licence from Russia. Salisbury Plain, Wiltshire, UK, October 2010.

David Kjaer / Great Bustard (Otis tarda), part of a reintroduction project with birds imported under DEFRA licence from Russia. Salisbury Plain, Wiltshire, UK, October 2010.

David Kjaer / Great Bustard (Otis tarda), part of a reintroduction project with birds imported under DEFRA licence from Russia. Salisbury Plain, Wiltshire, UK, October 2010.

David Kjaer / Great Bustard (Otis tarda), part of a reintroduction project with birds imported under DEFRA licence from Russia. Salisbury Plain, Wiltshire, UK, October 2010.

David Kjaer / Great Bustard (Otis tarda), part of a reintroduction project with birds imported under DEFRA licence from Russia. Salisbury Plain, Wiltshire, UK, October 2010.

David Kjaer / Great Bustard (Otis tarda), part of a reintroduction project with birds imported under DEFRA licence from Russia. Salisbury Plain, Wiltshire, UK, October 2010.

David Kjaer / Great Bustard (Otis tarda), part of a reintroduction project with birds imported under DEFRA licence from Russia. Salisbury Plain, Wiltshire, UK, October 2010.

Tui De Roy / Kori Bustard (Ardeotis kori), Lewa Wildlife Conservation Area, Kenya

David Kjaer / Two Great Bustard (Otis tarda) on Salisbury Plain, Wiltshire, UK - part of a reintroduction project with birds imported under DEFRA licence from Russia. October 2010.

David Kjaer / Two Great Bustard (Otis tarda) on Salisbury Plain, Wiltshire, UK - part of a reintroduction project with birds imported under DEFRA licence from Russia. October 2010.

David Kjaer / Four Great Bustard (Otis tarda) on Salisbury Plain, Wiltshire, UK - part of a reintroduction project with birds imported under DEFRA licence from Russia. October 2010.