Sheep walk as they are herded to summer pastures in Serra da Estrela, near Seia, Portugal June 27, 2015. In late June, shepherds young and old in the Seia region of central Portugal start guiding sheep, goats and cattle to the Serra da Estrela, the country’s highest mountains, in search of better pastures. There they stay until the end of September. Modern-day shepherds may have mobile phones to keep in touch with family and friends, but their lifestyle has changed little for centuries. The sound of cowbells and the bark of longhaired mastiffs starts early in the morning as the animals – often decorated with traditional woollen balls on their horns – are herded up steep, narrow paths. (Photo by Rafael Marchante/Reuters)

In this photo taken Thursday, August 13, 2015, a man walks past the charred remains of new cars at a parking lot near the site of an explosion at a warehouse in northeastern China's Tianjin municipality. Rescuers have pulled a survivor from an industrial zone about 32 hours after it was devastated by huge blasts in China's Tianjin port. Meanwhile, authorities are moving gingerly forward in dealing with a fire still smoldering amid potentially dangerous chemicals. (Photo by Ng Han Guan/AP Photo)

A topless woman walks through Bryant Park following the protest march called the GoTopless Day Parade Sunday, August 23, 2015, in New York. The parade took to the streets to counter critics who are complaining about topless tip-seekers in Times Square. Appearing bare-breasted is legal in New York. But Mayor Bill de Blasio and police Commissioner Bill Bratton say the body-painted women in the square who take photos with tourists are a nuisance. (Photo by Kevin Hagen/AP Photo)

Tourists walk behind a faded sign warning of tsunami hazard in Khao Lak, Phang Nga province December 15, 2014. Ahead of the anniversary of the 2004 tsunami, experts and officials say key weaknesses remain across the region in the system designed to warn people of the next disaster, and get them to safety. Thailand prepares to mark the tenth anniversary of the 2004 tsunami, the deadliest on the record, that killed at least 226,000 people in 13 Asian and African countries. (Photo by Damir Sagolj/Reuters)

Eighty one-year-old Sakon Haba (L) wearing loin cloth walks past a police station after he bathed in ice-cold water at the Teppozu Inari shrine in Tokyo January 11, 2015. According to organizers, about 100 participants took part in the Shinto ceremony to purify their souls and wish for good health in the new year. (Photo by Toru Hanai/Reuters)

A humanoid robot named “Robi” sits during a promotional event for the launch of a weekly Robi Magazine in Tokyo, Japan, 20 January 2015. Created by roboticist Tomotaka Takahashi, the 34-centimeter tall humanoid robot can recognize and respond to more than 200 words and phrases, walk and dance. Parts of the robot will be put on sale in a weekly magazine to be fully assembled with 70 issues. (Photo by Franck Robichon/EPA)

A man walks with a giant rake during carnival celebrations in Zubieta January 27, 2015. Bell carrying dancers known as Joaldunak from Zubieta and neighbouring Ituren visit each other's villages performing a ritual dance to ward off evil spirits and awaken the coming spring. Alongside the dancers, villagers dress in bizarre and frightening costumes to harass and scare visitors. (Photo by Vincent West/Reuters)

Indigenous woven backpacks called guayare are seen in front of a house in Paraitepui village, before a walking excursion to Mount Roraima, near Venezuela's border with Brazil January 13, 2015. A mysterious table-topped mountain on the Venezuela-Brazil border that perplexed 19th century explorers and inspired “The Lost World” novel is attracting ever more modern-day adventurers. (Photo by Carlos Garcia Rawlins/Reuters)