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

Luciano Candisani / Green Anaconda (Eunectes murinus) female constricting male after copulation, after which she will consume him, Brazil

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

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

Nick Saunders/ BIA / Ruddy Duck (Oxyura jamaicensis) male in courtship display, Saskatchewan, Canada

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

Steve Gettle / Great Egret (Ardea alba) in courtship display, North America

Steve Gettle / Western Grebe (Aechmophorus occidentalis) pair in courtship dance, North Dakota

Alan Murphy/ BIA / Northern Bobwhite (Colinus virginianus) female and male, Texas

Alan Murphy/ BIA / Killdeer (Charadrius vociferus) in broken wing display, Texas

Brais Seara Fernandez/ BIA / Atlantic Puffin (Fratercula arctica) pair preening, Farne Islands, United Kingdom