Jack Dykinga / Gaucho herding horses on the shoreline of Lago Almarga in the morning light, with Torres del Paine mountains in background under stormy skies. Patagonia, Chile.

Kristel Richard / Two cowboys mounted on a Pantaneiro stallion, round up a band of wild Pantaneiro horses, Pantanal, Mato Grosso do Sul, Brazil. August 2015.

Nick Garbutt / Adult Giant Anteater (Myrmecophaga tridactyla) with Pantaneiro Cowboy, Northern Pantanal, Mato Grosso State, Brazil, South America.

Angelo Gandolfi / Pantanal cowboy / gaucho (Pantaneiros) driving cattle. Pantanal, Brazil, August 2010.

Carol Walker / Cowboy galloping through snow, wearing thick sheepskin coat, Wyoming, USA, February 2012, model released

Kristel Richard / Cowboys rounding up a band of Criollo pure pedigree mares and foals, Estancia Ita Maria, Misiones, Paraguay, January 2012

Kristel Richard / An Indian cowboy has lost his balance from a bronc or wild paint horse during the All Indian Rodeo, at the annual Indian Crow Fair, at Crow Agency, near Billings, Montana, USA, August 2011, Sequence 3...

Jeff Vanuga / Horse and dog silhouetted at dusk. Bighorn Basin, Wyoming, USA. Model released

Christophe Courteau / Pantaneiros horsemen leading cattle and horse livestock along the Transpantaneira, Pantanal, Brazil, July 2008

Kristel Richard / A gaucho (cowboy) tries to remain on the back of a wild horse rearing vertically (Equus caballus) in the rodeo during the Fiesta de la Patria Gaucha, Tacuarembo, Uruguay, April 2008

Jeff Vanuga / Cowboy herding horses on winter day, Flitner ranch, Shell, Wyoming, USA, Model released, February 2008

Jeff Vanuga / Silhouette of two cowboys playing cards and drinking in a wagon, Wyoming, USA, September 2006, Model released

Jeff Vanuga / Cowboys working for the Bureau of Land Management round up wild horses / mustangs to remove them from public land, Red Desert, Wyoming, USA. Model released

Carol Walker / Cowboy riding over hill in snow, Sombrero Ranch, Craig, Colorado, USA Model released

Carol Walker / Cowboy riding bucking palomino horse, Sombrero Ranch, Craig, Colorado, USA Model released

Carol Walker / Cowgirl and cowboy herding horses in the snow, Flitner Ranch, Shell, Wyoming, USA Model released

Carol Walker / Cowboys sitting round camp fire, Flitner Ranch, Shell, Wyoming, USA Model released

Carol Walker / Silhouette of two cowboys at sunset, Flitner Ranch, Shell, Wyoming, USA Model released

Carol Walker / Cowboys running horses with group of horses through water at Sombrero Ranch, Craig, Colorado, USA Model released

Carol Walker / Cowboy on sorrel Quarter horse trotting in the snow at Flitner Ranch, Shell, Wyoming, USA Model released

Carol Walker / Cowboy on grey Quarter horse trotting in the snow at Flitner Ranch, Shell, Wyoming, USA Model released

Carol Walker / Cowboy running horse through water at Sombrero Ranch, Craig, Colorado, USA Model released

Carol Walker / Cowboy running horse through water, Sombrero Ranch, Craig, Colorado, USA Model released

Carol Walker / Cowgirl running paint horse through water, Sombrero Ranch, Craig, Colorado, USA Model released

Carol Walker / Silhouette of cowboy trotting at sunset, Flitner Ranch, Shell, Wyoming, USA Model released

Carol Walker / Cowboy riding in snow throwing a loop, Flitner Ranch, Shell, Wyoming, USA

Carol Walker / Silhouette of cowboy trotting, swinging a loop at sunset, Flitner Ranch, Shell, Wyoming, USA Model released

Carol Walker / Cowboy riding in snow throwing a loop, Flitner Ranch, Shell, Wyoming, USA Model released

Carol Walker / Cowboy holding newborn foal, Sombrero Ranch, Craig, Colorado, USA Model released

Carol Walker / Charro on a Black Andalusian stallion galloping in Ojai, California, USA, model released

Carol Walker / Cowboy, horse and dog on painted hills, Flitner Ranch, Shell, Wyoming, USA, model released

Carol Walker / Silhouette of three cowboys and a dog riding down a ridge, Flitner Ranch, Shell, Wyoming, USA, model released

Carol Walker / Four cowboys riding with cowdog, Flitner Ranch, Shell, Wyoming, USA, model released

Carol Walker / Cowboy riding through stream, Flitner Ranch, Shell, Wyoming, USA, model released

Carol Walker / Cowboy galloping while swinging a rope lassoo at sunset, Flitner Ranch, Shell, Wyoming, USA, model released

Carol Walker / Cowboys driving horses (Equus caballus) across the water at Sombrero Ranch, Craig, Colorado. Model released.

Carol Walker / Cowboy driving a horse at Sombrero Ranch, Craig, Colorado

Pete Oxford / Chagras or cowboys on an overnight ride at a hacienda during the annual cattle round-up, with Mt Antisana in the background, Ecuador

Pete Oxford / Chagra cowboys herding cattle and burning the hillsides to keep cattle on the move and rejuvenate the pasture at a hacienda during the annual overnight cattle round-up, Andes Mountains, Ecuador

Pete Oxford / Two Chagra cowboys on an overnight ride at a hacienda to herd cattle, Andes Mountains, Ecuador

Martin Willis / Domestic Cattle (Bos taurus) herd being herded by cowboys, Australia

Loic Poidevin / Gardian on Camargue horse rounding up bulls, Camargue, France, May 2017.

Loic Poidevin / Gardians on horseback, Camargue, France, May,

Doug Wechsler / Chagra (cowboy) on horseback with dog, Antisana Ecological Reserve, Ecuador. December 2016.

Hermann Brehm / Gauchos herding cattle on horseback, Pantanal, Brazil.

Kristel Richard / Man riding a Trote Y Galope stallion in canter, Rionegro, Antioquia, Colombia. August.

Kristel Richard / Man riding a Trocha mare in trot, Rionegro, Antioquia, Colombia.

Jouan Rius / Cowboy on horseback, Grand Staircase-Escalante National Monument, Utah, USA, March 2014.

Jouan Rius / Cowboy driving cattle, Grand Staircase-Escalante National Monument, Utah, USA, March 2014.

Jouan Rius / Cowboy driving cattle, Grand Staircase-Escalante National Monument, Utah, USA, March 2014.

Jose B. Ruiz / Patagonian Gaucho rider leading another horse, Torres del Paine. Patagonia, Puerto Natales, Chile, April.

Jose B. Ruiz / Horses tethered in snow, Torres del Paine, Patagonia, Puerto Natales, Chile. April.

Jose B. Ruiz / Gaucho with Patagonian flag, Torres del Paine. Patagonia, Puerto Natales, Chile. April 2016.

Iris Thorsteinsdottir / Horse riders herding group of icelandic horses in landscape, Iceland, July 2012.

Pete Oxford / Amerindian cowboy on horseback, Rurununi savanna, Guyana, South America

Pete Oxford / Amerindian cowboy detail of foot and traditional footwear, Rurununi savanna, Guyana, South America

Pete Oxford / Amerindian cowboy gear, Rurununi savanna, Guyana, South America

Pete Oxford / Tommy Kenyon, cowboy on Saddle Mountain (cattle) Ranch, Rurununi savanna, Guyana, South America

Pete Oxford / Tommy Kenyon, holding old family photograph, cowboy on Saddle Mountain (cattle) Ranch, Rurununi savanna, Guyana, South America

Pete Oxford / Tommy Kenyon, cowboy on Saddle Mountain (cattle) Ranch, Rurununi savanna, Guyana, South America

Pete Oxford / Aerial view of Amerindian cowboys on Dadanawa Ranch, Rurununi savanna, Guyana, South America

Pete Oxford / Amerindian cowboy on horseback at cattle ranch, Rurununi savanna, Guyana, South America

Cyril Ruoso / Two cowboys riding horses through desert, Vizcaino Desert, Baja California, Mexico, May 2008.

Cyril Ruoso / Cowboy on horse, galloping through Vizcaino Desert, Baja California, Mexico, May 2008.

Cyril Ruoso / Cowboy's legs wearing chaps over trousers to protect himself from the spiny desert, Vizcaino Desert, Baja California, Mexico, May 2008.

Kristel Richard / Peone or cowboy riding his Pantaneiro stallion, Pantanal, Mato Grosso do Sul, Brazil. August.

Kristel Richard / Cowboy on his Pantaneiro stallion, lassoing a Nelore calf for vaccination, among a herd of Nerole cattle, Pantanal, Mato Grosso do Sul, Brazil. August 2015.

Kristel Richard / Cowboy mounted on a Pantaneiro stallion, rounds up a band of wild Pantaneiro horses, Pantanal, Mato Grosso do Sul, Brazil.

Kristel Richard / Two cowboys mounted on Pantaneiro stallion, round up a band of wild Pantaneiro horses in water, Pantanal, Mato Grosso do Sul, Brazil. August 2015.

Kristel Richard / Cowboy mounted on a Pantaneiro stallion, rounds up a band of wild Pantaneiro horses in water, Pantanal, Mato Grosso do Sul, Brazil, August 2015.

Kristel Richard / Two cowboys mounted on a Pantaneiro stallion, rounds up a band of wild Pantaneiro horses, Pantanal, Mato Grosso do Sul, Brazil.

Kristel Richard / Cowboy mounted on a Pantaneiro stallion, rounding up a band of wild Pantaneiro horse in water, Pantanal, Mato Grosso do Sul, Brazil.

Kristel Richard / Peone or cowboy gallops on his Pantaneiro stallion in a lagoon, Pantanal, Mato Grosso do Sul, Brazil.

Jeff Vanuga / 'Guardian' cowboys moving the white horses of the Camargue, France, April 2015.

Chris Mattison / Gauchos and their dogs, Patagonia, Chile, March 2015.

Peter Cairns / Sign on Teton Pass overlooking Jackson Hole, Wyoming, USA. February 2014.

Angelo Gandolfi / Cowboys herding cattle, Santa Catarina, Brazil. September 2010.

Carol Walker / Herd of Quarter and Azteca horses with rancher, Nebraska, USA, June 2012.

Carol Walker / Cow boy on horse, with cattle, Martinsdale, Montana, USA.

Carol Walker / Man on Quarter horse silhouetted at dusk, at ranch, Shell, Wyoming, USA. February.

Luiz Claudio Marigo / Cowboy of Pantanal Matogrossense driving a herd of cattle by the Transpantaneira Road Pantanal, Mato Grosso State, Western Brazil, October 2012.

Luiz Claudio Marigo / Cowboy of Pantanal Matogrossense driving a herd of cattle by the Transpantaneira Road Pantanal, Mato Grosso State, Western Brazil, October 2012.

Angelo Gandolfi / Pantanal cowboy/ gaucho (Pantaneiro) Pantanal, Brazil, August 2010.

Ben Lascelles / A 'Gaucho', cowboy of Gran Chaco, Santa Olga, Chaco Province, Argentina. October

Carol Walker / Cowboy and horse, Wyoming, USA, February 2012, model released

Carol Walker / Two mounted cowboys riding in snow, carrying guns, Wyoming, USA, February 2012, model released

Carol Walker / Mounted cowboy riding in snow, galloping, Wyoming, USA, February 2012, model released

Carol Walker / Mounted cowboy riding in snow, Wyoming, USA, model released

Carol Walker / Cowboy rounding up grey quarter horse, running through snow, Wyoming, USA, February 2012

Carol Walker / Cowboys sitting round camp fire at dusk, one playing guitar, Wyoming, USA, February 2012, model released

Carol Walker / Cowboys sitting round camp fire at dusk, one playing the guitar, Wyoming, USA, February 2012, model released

Carol Walker / Cowboys sitting round camp fire at dusk, Wyoming, USA, February 2012, model released

Carol Walker / Cowboy rounding up and lassooing paint quarter horses in snow, Wyoming, USA, February 2012, model released

Carol Walker / Cowboy lassooing paint quarter horse in snow, Wyoming, USA, February 2012, model released

Carol Walker / Detail of boots, stirrup and spurs of cowboy, Wyoming, USA, model released

Carol Walker / Detail of boots, stirrup and spurs of cowboy, Wyoming, USA, model released