In this May 16, 2017 photo, a cowboy serves “Terere”, an herbal “mate” beverage, served ice-cold in an ox horn, in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. “Terere” is sipped through a silver straw, the personal property of each cowboy. (Photo by Eraldo Peres/AP Photo)





In this May 18, 2017 photo, Rene de Almeida, who leads a group of cowboys, stands on a farm at dawn in Porto Rolon near the Taquari River in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. While ranchers on the coasts can transport cattle with trucks, the excess of water and the shortage of roads make that impossible in the world's biggest floodplain. (Photo by Eraldo Peres/AP Photo)





In this May 16, 2017 photo, cowboys drink “Terere”, an herbal “mate” beverage served ice-cold in a glass made out of an ox horn in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. On thier feet hours before sunrise, the cowboys get ready to wake up the herd of oxen for a new day in the three-week pilgrimage in search of grass to graze. (Photo by Eraldo Peres/AP Photo)





In this May 16, 2017 photo, a handmade whip handle, in the shape of a boot, hangs in a cowboy camp in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. The whip was made by one of the ranch hands who helps round up cattle. (Photo by Eraldo Peres/AP Photo)





In this May 17, 2017 photo, a butterfly perches near a cowboy's “Guampa”, or a drinking ox horn, in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. The horn is used to drink “Terere”, an herbal “mate” beverage served ice cold and sipped through a silver straw. (Photo by Eraldo Peres/AP Photo)





In this May 18, 2017 photo, a cowboy prepares his mounts to continue the journey in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. Cowboys earn an average of $18 dollars a day, and the leader of the group can earn as much as $285 per day. (Photo by Eraldo Peres/AP Photo)





In this May 16, 2017 photo, cowboy Renan Lopes Nascimento holds his reigns as he arrives to a ranch to spend the night, in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. (Photo by Eraldo Peres/AP Photo)





In this May 17, 2017 photo, cowboys prepare their mounts to continue their journey in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. The crossing of the Taquari River is a key passage in the journey, where they have to guide 520 oxen through the depths of the overflowing river, all from the top of a horse. (Photo by Eraldo Peres/AP Photo)





In this May 17, 2017 photo, the Milky Way lights up the sky above a ranch where cowboys spend the night during a round up, in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. Ranchers here contract out the grazing business, and being a cowboy is reasonably well-paying for the region. (Photo by Eraldo Peres/AP Photo)





In this May 17, 2017 photo, cowboys chat as they eat a “churrasco”, or barbecue, at a ranch in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. Each day, the men and animals traverse about 11 miles from dawn until 3 p.m., in temperatures averaging about 90 degrees Fahrenheit during the day. (Photo by Eraldo Peres/AP Photo)





In this May 17, 2017 photo, cowboy cook Odair Batista carries a case with food in Corumba, the Pantanal wetlands of Mato Grosso do Sul state, Brazil. Dressed with leather chaps on top of their jeans, stetson hats and a machete attached to their waists, before setting off, the men finish their breakfast with Terere, an herbal “mate” beverage served ice cold in an ox drinking horn. (Photo by Eraldo Peres/AP Photo)





In this May 18, 2017 photo, a marsh deer stands near a herd of oxen in Corumba, in the Pantanal wetlands of Mato Grosso do Sul, state, Brazil. At different moments during trips by cowboys and their cattle, men and beasts cross paths with macaws, deer and pit vipers, all seemingly unfazed by their presence. (Photo by Eraldo Peres/AP Photo)





In this May 17, 2017 photo, cowboy Joao Aquino Pereira smokes at dawn on a ranch in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. (Photo by Eraldo Peres/AP Photo)





In this May 17, 2017 photo, cowboy Joao Aquino Pereira rides his horse in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. Each day, the men and animals traverse about 11 miles from dawn until 3 p.m., in temperatures averaging about 90 degrees Fahrenheit during the day. (Photo by Eraldo Peres/AP Photo)





In this May 17, 2017 photo, cowboys guide oxen through a ford of the Taquari River in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. Greener pastures grow under water in the Pantanal de Mato Grosso do Sul, an immense area of wetlands in western Brazil. (Photo by Eraldo Peres/AP Photo)





In this May 17, 2017 photo, cowboy Joao Aquino Pereira, 66, cooks “churrasco”, or barbecue, at a ranch in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. Dressed with leather chaps on top of their jeans, Stetson hats and machetes attached to their waists, before setting off the men finish their breakfast with “terere”, an herbal “mate” tea served ice cold from a cup made out of an ox horn. (Photo by Eraldo Peres/AP Photo)





In this May 16, 2017 photo, Araras ,or Macaws, are seen at a ranch in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. At different moments during a cowboy round-up, they crosses paths with macaws, deer and pit vipers, all seemingly unfazed by their presence. (Photo by Eraldo Peres/AP Photo)





In this May 17, 2017 photo, cook Odair Batista prepares a meal for cowboys in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. Batista cooked yucca and a mix of rice, meat and beans. (Photo by Eraldo Peres/AP Photo)





In this May 18, 2017 photo, Joao Aquino Pereira, right, talks with fellow cowboy Rene Almeida at dawn in Corumba, Pantanal wetlands, Mato Grosso do Sul state, Brazil. On his feet hours before sunrise, 66-year-old Pereira readies the horses and wakes up the herd of oxen for a new day in the three-week pilgrimage in search of grass. “Today's going to be one of those days”, says the old cowboy, forecasting the weather by looking up at the red skies. “It seems like it'll be a hot one and we still need to prepare the cattle to go across the river”. (Photo by Eraldo Peres/AP Photo)





In this May 16, 2017 photo, an “Arara”, or Macaw flies low over a ranch in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. At different moments during a three-week pilgrimage in search of grass to graze for cattle, cowboys cross paths with macaws, deer and pit vipers, all seemingly unfazed by their presence. (Photo by Eraldo Peres/AP Photo)





In this May 18, 2017 photo, cowboys guide the herd to the Taquari River, in Corumba, Mato Grosso do Sul state, Brazil. The crossing of the river with 520 oxen requires all the skill the cowboys have amassed in decades of experience. (Photo by Eraldo Peres/AP Photo)





In this May 18, 2017 photo, cowboy cook Odair Batista crosses the Taquari River with a horse train carrying food for the cowboys in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. Hardly recognizable in the developed world, working as a cowboy is still a way of life in rural areas of Latin America's largest nation. (Photo by Eraldo Peres/AP Photo)





In this May 17, 2017 photo, a cowboy stands under a tree at dusk on a farm in Corumba, in the Pantanal wetlands of Mato Grosso do Sul state, Brazil. Working as a cowboy is still a way of life in rural areas of Latin America’s largest nation and is reasonably well-paying for the region. (Photo by Eraldo Peres/AP Photo)