Adult arctic terns (Sterna paradisaea) in dispute on Flatey Island, Iceland, Polar Regions

Male black grouse (Lyrurus tetrix) fighting on snow covered field, Finland

Adult female lesser frigatebirds (Fregata ariel), in aerial combat, Niau Island, Tuamotus, French Polynesia, South Pacific, Pacific

Adult black-legged kittiwake (Rissa tridactyla) in combat with a second kittiwake near Alexander Island, Franz Josef Land, Russia, Arctic Ocean, Eurasia

Chacochachalaca (Ortalis canicollis), aerial combat, Pantanal, Brazil, South America

Chacochachalaca (Ortalis canicollis), aerial combat, Pantanal, Brazil, South America

White-tailed eagle (Haliaeetus albicilla) in aerial combat, Poland, Europe

White-tailed eagle (Haliaeetus albicilla) in aerial combat, Poland, Europe

White-tailed eagle (Haliaeetus albicilla) in aerial combat, Poland, Europe

White-tailed eagle (Haliaeetus albicilla) in aerial combat, Poland, Europe

White-tailed eagle (Haliaeetus albicilla) in aerial combat, Poland, Europe

White-tailed eagle (Haliaeetus albicilla) in aerial combat, Poland, Europe

Two great crested grebe (Podiceps cristatus) in combat, in splendour, Chiemsee, Upper Bavaria, Bavaria, Germany, Europe