Philippe Clement / European jackdaw (Corvus monedula) mirror image composite of two birds in different threat postures, on the left - the forward-threat posture, with the bird holding its body horizontally and thrusting...

Nick Turner / Bromeliad in flower {Aechmea magdalenae} Corcovado NP, Costa Rica

Sumio Harada / Mountain Goat (Oreamnos americanus) pair fighting for salt rights, male at left threatens female at right who lowers her rump in defense, Walton Goat Lick, Glacier National Park, Montana

Joel Sartore / Photo Ark / Siberian crane (Leucogeranus leucogeranus) female looking around, then the animal lowers its head and ruffles its feathers. International Crane Foundation, Baraboo, Wisconsin. Controlled condiitons. C...