Chase Dekker / Moose (Alces alces shirasi) bull flehming in autumn, Grand Teton National Park, Wyoming

Chase Dekker / Moose (Alces alces shirasi) bull flehming in autumn, Grand Teton National Park, Wyoming

Donald M. Jones / Elk (Cervus elaphus) bull flehming, western Canada

Richard Du Toit / Burchell's Zebra (Equus burchellii) flehming, Kwazulu Natal, South Africa

Ingo Arndt / Mountain Lion (Puma concolor) female scenting, Torres del Paine National Park, Patagonia, Chile

Ingo Arndt / Mountain Lion (Puma concolor) female scenting, Torres del Paine National Park, Patagonia, Chile

Donald M. Jones / Bighorn Sheep (Ovis canadensis) ram flehming near ewe, western Montana

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) ram flehming, Waterton Canyon, Colorado

Adri de Visser / African Lion (Panthera leo) male flehming, Masai Mara, Kenya

Suzi Eszterhas / African Lion (Panthera leo) male flehming, Sabi-sands Game Reserve, South Africa

Yva Momatiuk & John Eastcott / Angolan Giraffe (Giraffa giraffa angolensis) mother and calf, with male flehming to see if female is in estrus, Etosha National Park, Namibia

Mark Raycroft / Mule Deer (Odocoileus hemionus) buck flehming, North America