David Pattyn / Shag (Phalacrocorax aristotelis) spreading wings to dry, Hornoya, Varanger, Finnmark, Norway, April.

David Pattyn / Black necked grebe (Podiceps nigricollis) adult bird spreading its wings in anticipation of the partner during courtship. The Netherlands.April 2014

David Pattyn / Black necked grebe (Podiceps nigricollis) adult spreading its wings during the courtship dance. This bird is waiting for the submerged partner to emerge from the water and perform a dance in front. Th...

David Pattyn / Black necked grebe (Podiceps nigricollis) adult bird spreading its wings and waiting for the submerged partner to appear in front and perform the courtship dance. This is early in the breeding season,...

Luiz Claudio Marigo / Sunbittern (Eurypyga helias) spreading its wings while standing in water. The Pantanal wetlands of Mato Grosso State, Brazil, November.

Bernard Castelein / Cinereous / European black vulture (Aegypius monachus) spreading wings on ground, Rajasthan, India

Mitsuaki Iwago / Black-footed Albatross (Phoebastria nigripes) juvenile exercising its wings, Hawaii

Luciano Candisani / Black-browed Albatross (Thalassarche melanophrys) flying, Steeple Jason Island, Falkland Islands

Suzi Eszterhas / Black-browed Albatross (Thalassarche melanophrys) flying, endangered, Steeple Jason, Falkland Islands

Paul Bertner / Peacock Katydid (Pterochroza ocellata) in defensive posture, Tambopata-Candamo Nature Reserve, Peru

Alan Murphy/ BIA / Baltimore Oriole (Icterus galbula) males fighting, Texas

Alan Murphy/ BIA / Baltimore Oriole (Icterus galbula) males fighting, Texas

Paul Souders/ Worldfoto / Black Heron (Egretta ardesiaca) canopy hunting, Chobe River, Chobe National Park, Botswana

Donald M. Jones / American Avocet (Recurvirostra americana) pair courting, Montana

Ingo Arndt / Upland Goose (Chloephaga picta) male stretching, Torres del Paine National Park, Patagonia, Chile

Thomas Marent / Sparkling Violet-ear (Colibri coruscans) hummingbird bathing, Bogota, Colombia

Alan Murphy/ BIA / Northern Cardinal (Cardinalis cardinalis) male and Pyrrhuloxia (Cardinalis sinuatus) male fighting, Texas

Benjamin Olson / Gentoo Penguin (Pygoscelis papua) wading, Antarctica

Benjamin Olson / Gentoo Penguin (Pygoscelis papua) wet from rain due to climate change, Antarctica

Chase Dekker / Common Loon (Gavia immer) spreading wings, Monterey Bay, California

Donald M. Jones / Common Loon (Gavia immer) stretching, Troy, Montana

Jan Wegener/ BIA / Grey Heron (Ardea cinerea) spreading wings on frozen lake, Berlin, Germany

Tui De Roy / Brown Pelican (Pelecanus occidentalis) hunting baitfish, Urvina Bay, Isabela Island, Galapagos Islands, Ecuador

Paul Bertner / Fulgorid Planthopper (Phrictus quinquepartitus) in defensive posture, Braulio Carrillo National Park, Costa Rica

Ingo Arndt / Purple Heron (Ardea purpurea) pair courting and building nest in reeds, Germany

Thomas Marent / Velvet-purple Coronet (Boissonneaua jardini) hummingbird in defensive posture, Las Tangaras Bird Reserve, Colombia

Alain Ghignone/ BIA / Montagu's Harrier (Circus pygargus) male landing, Andalusia, Spain

Thomas Hinsche/ BIA / Common Buzzard (Buteo buteo) pair fighting, Saxony-Anhalt, Germany

Alain Ghignone/ BIA / Eurasian Hoopoe (Upupa epops) stretching, Aosta Valley, Italy

Thomas Hinsche/ BIA / Common Buzzard (Buteo buteo) pair fighting, Saxony-Anhalt, Germany

Ralf Kistowski/ BIA / Pied Kingfisher (Ceryle rudis) female landing, Gambia

Glenn Bartley/ BIA / Golden-breasted Puffleg (Eriocnemis mosquera) feeding on flower nectar, Colombia

Peter Schwarz/ BIA / Dryad (Minois dryas) butterfly, Poland

Eric Sohn Joo Tan/ BIA / Black-winged Lapwing (Vanellus melanopterus) calling during defensive display, KwaZulu-Natal, South Africa

Ralf Kistowski/ BIA / Common Kingfisher (Alcedo atthis) parent spreading wings near fledgling, North Rhine-Westphalia, Germany

Alan Murphy/ BIA / Say's Phoebe (Sayornis saya) landing, Texas

Michael Milicia/ BIA / Piping Plover (Charadrius melodus) stretching, Massachusetts

Donald M. Jones / Wood Duck (Aix sponsa) drake stretching wings, central Montana

Winfried Wisniewski / Ruff (Philomachus pugnax) male displaying at lek, Varanger Peninsula, Norway

Suzi Eszterhas / Snowy Egret (Egretta thula) four week old chick begging for food, Sonoma County, California

Stefan Christmann / Emperor Penguin (Aptenodytes forsteri) stretching wings, Queen Maud Land, Antarctica

Donald M. Jones / Burrowing Owl (Athene cunicularia) owlets at burrow with one stretching, Montana

Silvia Reiche / Peacock Butterfly (Inachis io), Netherlands

Silvia Reiche / Peacock Butterfly (Inachis io), Netherlands

Silvia Reiche / Painted Lady (Vanessa cardui) butterfly, Netherlands

Thomas Hinsche / Ring-necked Pheasant (Phasianus colchicus) male in terriorial display, Texel, Netherlands

Suzi Eszterhas / Hyacinth Macaw (Anodorhynchus hyacinthinus) pair fighting, Pantanal, Brazil.Sequence 3 of 4

Duncan Usher / Common Buzzard (Buteo buteo) pair fighting over food in winter, Germany