Nick Garbutt / Lesser rhea (Rhea pennata) male and chicks in grassland. Torres del Paine National Park, Patagonia, Chile. November.

Nick Garbutt / Darwin's rhea (Pterocnemia pennata) with tower peaks in background. Torres del Paine National Park, Patagonia, Chile. December.

Ingo Arndt / Lesser Rhea (Rhea pennata) killed and covered by Puma (Puma concolor), Torres del Paine National Park, Patagonia, Chile

Shane P. White / Lesser Rhea (Rhea pennata), Torres del Paine National Park, Patagonia, Chile

Benjamin Olson / Lesser Rhea (Rhea pennata), Torres del Paine National Park, Chile

Agustin Esmoris / Lesser Rhea (Rhea pennata) crossing road, Peninsula Valdez, Argentina

Bernard Castelein / Lesser rhea (Pterocnemia pennata) Quetena, Altiplano, Bolivia

Bernard Castelein / Lesser rhea (Pterocnemia pennata) Quetena, Altiplano, Bolivia

Agustin Esmoris / Lesser Rhea (Rhea pennata), Punta Tombo National Reserve, Argentina

Agustin Esmoris / Lesser Rhea (Rhea pennata), Punta Tombo National Reserve, Argentina

Agustin Esmoris / Lesser Rhea (Rhea pennata), Punta Tombo National Reserve, Argentina

Ingo Arndt / Darwin's / Lesser rhea {Rhea / Rhea pennata} Torres del Paine NP, Patagonia, Chile

Sebastian Kennerknecht / Lesser Rhea (Rhea pennata), Torres del Paine National Park, Patagonia, Chile

Bernard Castelein / Lesser rhea (Pterocnemia pennata) altiplano, Bolivia September

Bernard Castelein / Lesser rhea (Pterocnemia pennata) altiplano, Bolivia September

Jose B. Ruiz / Lesser rhea / Darwin's rhea (Rhea pennata) Torres del Paine. Patagonia, Puerto Natales, Chile.

Chris Mattison / Darwin's rhea (Rhea pennata) in pampas, Patagonia, Chile.

Gabriel Rojo / Lesser rhea (Pterocnemia pennata) Torres del Paine National Park, Chile

Gabriel Rojo / Lesser rhea (Pterocnemia pennata) Valdes Peninsula, Chubut, Patagonia, Argentina.

Gabriel Rojo / Lesser rhea (Pterocnemia pennata) with chicks under wings. Valdes Peninsula, Chubut, Patagonia, Argentina.

Gabriel Rojo / Lesser rhea (Pterocnemia pennata) with chicks under wings. Valdes Peninsula, Chubut, Patagonia, Argentina.

Gabriel Rojo / Lesser rhea (Pterocnemia pennata) with chicks. Valdes Peninsula, Chubut, Patagonia, Argentina.

Gabriel Rojo / Lesser rhea (Pterocnemia pennata) portrait, Valdes Peninsula, Chubut, Patagonia, Argentina.

Gabriel Rojo / Lesser rhea (Pterocnemia pennata) chick, Valdes Peninsula, Chubut, Patagonia, Argentina.

Gabriel Rojo / Lesser rhea (Pterocnemia pennata) chick, Valdes Peninsula, Chubut, Patagonia, Argentina.

Gabriel Rojo / Lesser rhea (Pterocnemia pennata) with chicks on coast, Valdes Peninsula, Chubut, Patagonia, Argentina.

Gabriel Rojo / Lesser rhea (Pterocnemia pennata) chick, rear view. Valdes Peninsula, Chubut, Patagonia, Argentina.

Gabriel Rojo / Lesser rhea (Pterocnemia pennata) Valdes Peninsula, Chubut, Patagonia, Argentina.

Gabriel Rojo / Lesser rhea (Pterocnemia pennata) chick, Valdes Peninsula, Chubut, Patagonia, Argentina.

Gabriel Rojo / Lesser rhea (Pterocnemia pennata) chick, Valdes Peninsula, Chubut, Patagonia, Argentina.

David Tipling / Darwin's Rhea (Rhea pennata) Beagle Channel, Chile.

Oscar Diez / Lesser Rhea (Rhea pennata), Chile

Kevin Schafer / Lesser Rhea (Rhea pennata) egg collected from nest, Puerto Deseado, Argentina

Matthias Breiter / Lesser Rhea (Rhea pennata) in pampas, Punta Arenas, Chile

Hiroya Minakuchi / Lesser Rhea (Rhea pennata) father and chicks, Valdes Peninsula, Argentina

Oriol Alamany / Darwin's rhea (Rhea pennata), Torres del Paine National Park, Patagonia, Chile

Oriol Alamany / Darwin's rhea (Rhea pennata), resting on ground, Torres del Paine National Park, Patagonia, Chile

Oriol Alamany / Darwin's rhea (Rhea pennata), head portrait, Torres del Paine National Park, Patagonia, Chile

Oriol Alamany / Darwin's rhea (Rhea pennata), resting on ground, Torres del Paine National Park, Patagonia, Chile

Oriol Alamany / Darwin's Rhea (Rhea pennata), Torres del Paine National Park, Patagonia, Chile, January

Gabriel Rojo / Lesser / Darwin's rhea (Rhea pennata) Monte Leon National Park, Santa Cruz Province, Patagonia, Argentina, December

Hanne & Jens Eriksen / Lesser / Darwin's Rhea {Rhea pennata}portrait resting on ground, Torres Del Paine, Chile.

Hermann Brehm / Darwin's / Lesser rhea {Rhea pennata} Torres del Paine NP, Chile

Konrad Wothe / Lesser Rhea (Rhea pennata) with chicks, Peru, Chile, and Argentina

Konrad Wothe / Lesser Rhea (Rhea pennata) pair, Patagonia, Argentina

Daniel Gomez / Darwin's / Lesser rhea grazing on steppe {Rhea pennata} Estancia Chali-Aike, Patagonia, Argentina, South America

Agustin Esmoris / Lesser Rhea (Rhea pennata) road sign, Argentina

Agustin Esmoris / Lesser Rhea (Rhea pennata) chick killed on road, Argentina

Agustin Esmoris / Lesser Rhea (Rhea pennata) chick killed on road, Argentina

Agustin Esmoris / Lesser Rhea (Rhea pennata) chick killed on road, Argentina

Agustin Esmoris / Lesser Rhea (Rhea pennata) chick killed on road, Argentina

Agustin Esmoris / Lesser Rhea (Rhea pennata) juvenile hiding in grass, Argentina

Agustin Esmoris / Lesser Rhea (Rhea pennata) juvenile, Argentina

Ingo Arndt / Mountain Lion (Puma concolor) male caching Lesser Rhea (Rhea pennata) kill, Torres del Paine National Park, Patagonia, Chile

Sean Crane / Lesser Rhea (Rhea pennata), Torres del Paine National Park, Patagonia, Chile

Glenn Bartley/ BIA / Lesser Rhea (Rhea pennata), Andes, Chile

Benjamin Olson / Lesser Rhea (Rhea pennata), Torres del Paine National Park, Chile

Agustin Esmoris / Lesser Rhea (Rhea pennata) footprint, Argentina

Agustin Esmoris / Lesser Rhea (Rhea pennata), Punta Tombo National Reserve, Argentina

Agustin Esmoris / Lesser Rhea (Rhea pennata), Punta Tombo National Reserve, Argentina

Sebastian Kennerknecht / Lesser Rhea (Rhea pennata), Torres del Paine National Park, Patagonia, Chile

Sebastian Kennerknecht / Lesser Rhea (Rhea pennata), Abra Granada, Andes, northwestern Argentina

Hiroya Minakuchi / Lesser Rhea (Rhea pennata) father and chicks, Valdes Peninsula, Argentina

Lucas Bustamante / Darwin's rheas / Lesser rheas (Rhea pennata) on grassland at sunset, Torres del Paine National Park, Magallanes, Chile.

Lucas Bustamante / Three Darwin's rheas / Lesser rheas (Rhea pennata), Torres del Paine National Park, Magallanes, Chile.

Lucas Bustamante / Darwin's rhea / Lesser rhea (Rhea pennata) silhouetted on hilltop at dusk, with lenticular clouds in sky above, Torres del Paine National Park, Magallanes, Chile.

Ernie Janes / Rhea (Rhea pennata) head profile portrait. Captive.

Ashley Cooper / Darwin's rhea (Rhea pennata pennata) in grassland beside fence. North of Punta Arenas, Magallanes, Chile. January.

Simon Littlejohn / Darwin's rhea (Rhea pennata) preening its wing feathers, Torres del Paine National Park, Chile, July.

Hanne & Jens Eriksen / Lesser rhea (Rhea pennata) walking in field, Germany, March