A wrestler from the Nuba Mountains tribe is seen during a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. The International Day of the World's Indigenous Peoples is observed on August 9 annually. (Photo by Mohamed Nureldin Abdallah/Reuters)

A man dressed as Hindu Lord Shiva looks into the mirror as he gets ready to take part in a religious procession on the eve of Janmashtami festival in Amritsar, India, September 4, 2015. The festival, which marks the birth anniversary of Lord Krishna, will be celebrated across India on Saturday. (Photo by Munish Sharma/Reuters)

A street cleaner demonstrates his martial arts skills in front of a closed shop near Beijing's Tiananmen Square September 2, 2015 as the capital prepares for tomorrow's parade. (Photo by Damir Sagolj/Reuters)

Yawalapiti children play during the preparations for the celebration of “quarup”, a ritual held to honor in death a person of great importance to them, in the Xingu National Park, Mato Grosso State, May 7, 2012. (Photo by Ueslei Marcelino/Reuters)

A pro-democracy protester wearing a Guy Fawkes mask holds a yellow umbrella and a banner in the part of Hong Kong's financial central district protesters are occupying November 2, 2014. The former British colony of Hong Kong, which returned to Chinese rule in 1997, has witnessed a month of protests calling on the Beijing-backed government to keep its promise of introducing universal suffrage. The protests have for the most part been peaceful, with occasional clashes between the student-led protesters and Beijing supporters seeking to move them from the streets. (Photo by Damir Sagolj/Reuters)

Crocodile skin is seen at a workshop in the old Medina of Marrakesh December 13, 2014. (Photo by Youssef Boudlal/Reuters)

A migrant carries his belongings as he arrives at the Beijing railway station to catch a train in Beijing, Friday, February 13, 2015. (Photo by Andy Wong/AP Photo)

A man falls from an ox cart as he competes during an ox cart competition near U Bein bridge, in Mandalay March 22, 2015. (Photo by Soe Zeya Tun/Reuters)