Bence Mate / Red footed falcon (Falco vespertinus) pair mating, Lake Csaj, Kiskunsagi National Park, Pusztaszer, Hungary. February.

Bence Mate / Red footed falcon (Falco vespertinus) pair mating, Lake Csaj, Kiskunsagi National Park, Pusztaszer, Hungary. February.

Michael Milicia/ BIA / Piping Plover (Charadrius melodus) in broken wing display, Massachusetts

Matthias Breiter / Polar Bear (Ursus maritimus) males fighting, Hudson Bay, Manitoba, Canada

Lou Coetzer / Pintailed whydah (Vidua macroura) male displaying to female, Masai Mara, Kenya.

Andres M. Dominguez / Red deer (Cervus elaphus) stag and two hinds, Los Alcornocales Natural Park, southern Spain, September.

Markus Varesvuo / Female Capercaillie (Tetrao urogallus) ready to mate, Vaala, Finland, May.

Donald M. Jones / Blue Grouse (Dendragapus obscurus) male displaying, western Montana

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

Thomas Marent / Gelada Baboon (Theropithecus gelada) male and females huddling for warmth, Simien Mountains National Park, Ethiopia

Thomas Marent / Mandrill (Mandrillus sphinx) male in defensive posture, Lekedi Natural Preserve, Gabon

Thomas Marent / Drill (Mandrillus leucophaeus) male in defensive posture, Afi Mountain Wildlife Sanctuary, Nigeria