Marie Read / American avocets (Recurvirostra americana) two during aggressive (territorial) encounter, Bear River Migratory Bird Refuge, Utah, USA, May.

Marie Read / Tufted puffin (Fratercula cirrhata), adult in breeding plumage flying in preparing to land, St. Paul, Pribilof Islands, Alaska, USA, July.

Marie Read / Crested caracaras (Caracara cheriway), midair aggressive interaction between two for access to perch, Martin Refuge, Rio Grande Valley, Texas, USA, March.

Loic Poidevin / Two Western marsh harriers (Circus aeruginosus) interacting in midair, Marais Breton, Vendée, France, February.

Marie Read / Cliff Swallow (Petrochelidon pyrrhonota) adult in flight, Bear River Migratory Bird Refuge, Utah, USA, May.

Wim van den Heever / Steller's sea eagle (Haliaeetus pelagicus) two subadults fighting in midair, Shiretoko Peninsula, Hokkaido, Japan

Mark Moffett / Comb Footed Spider (Theridiidae) with Green Tree Ant (Oecophylla smaragdina) prey in midair, where other ants cannot come to its defense, Daintree, Queensland, Australia

Marie Read / Two White Ibis (Eudocimus albus) during a midair fight over a feeding spot in a Florida wetland, USA, March.

Marie Read / Two White Ibis (Eudocimus albus) during a midair fight over a feeding spot in a Florida wetland, USA, March.

Marie Read / Two White Ibis (Eudocimus albus) during a midair fight over a feeding spot in a Florida wetland, USA, March.

Marie Read / Elegant Tern (Sterna / Thalasseus elegans) shaking water droplets off its feathers in midair after diving for fish. Bolsa Chica Ecological Reserve, California, USA, July.

Marie Read / Elegant Tern (Sterna / Thalasseus elegans) fighting in midair. Bolsa Chica Ecological Reserve, California, USA, July. (Digitally retouched image / wingtip at left & space added)