A herder stops for reindeers to have a rest while riding along the tundra area in Nenets Autonomous District, Russia, November 27, 2016. In Russia's remote Arctic regions reindeer herding has been a way of life for centuries. Each winter herders in Russia's sparsely populated Nenets Autonomous District corral their reindeers into open-air pens before selecting weak animals to be culled... (Photo by Sergei Karpukhin/Reuters)

People wearing bear fur costumes dance during the annual bear ritual gathering in Comanesti, Romania, Friday, December 30, 2016. In pre-Christian rural traditions, dancers wearing colored costumes or animal furs, toured from house to house in villages singing and dancing to ward off evil, in the present the tradition has moved to Romania's cities too, where dancers travel to perform the ritual for money. (Photo by Vadim Ghirda/AP Photo)

Iraqi rapid response forces take a selfie picture outside a hospital damaged by clashes during a battle between Iraqi forces and Islamic State militants in the Wahda district of eastern Mosul, Iraq, January 8, 2017. (Photo by Alaa Al-Marjani/Reuters)

Mohammad, a 13-year-old fighter from the “Free Syrian Army”, plays with a cat in Aleppo's Bustan al-Basha district, Syria October 28, 2013. Mohammad joined the Free Syrian Army after his father died during clashes with the Syrian regime. The gun he is using was his father's. (Photo by Molhem Barakat/Reuters)

Framed by the setting sun, an American Bison grazes at the Tallgrass Prairie National Preserve on Tuesday, April 28, 2015, near Strong City, Kan. The buffalo herd at Tallgrass is one of the few herds of wild bison left in the United States. (Photo by Travis Heying/The Wichita Eagle via AP Photo)

A woman wearing a mask reacts at her garden which locates next to chimneys of coal-fired power plant in Shijiazhuang, Hebei province, China, January 28, 2015. Beijing introduced tougher regulations this year to combat pollution, keen to overhaul China's unwanted image of smog-choked cities, fouled waterways and heavy-metal tainted soil. (Photo by Kim Kyung-Hoon/Reuters)

A woman gets ready for her performance at the backstage of the Heart restaurant in Ibiza on June 29, 2015. Take the Spanish chefs Ferran and Albert Adria, the Cirque du Soleil founder French Guy Laliberte and contemporary artists such as Japanese Takashi Murakami. Put them together on the luxurious Mediterranean island of Ibiza and shake well to get “Heart” an innovative multi-sensory experience. The idea of provoking emotions through a collision of avant-garde creativities appeared two years ago from Adria brothers and Laliberte's passion about art and cuisine. They met a decade ago at the famous restaurant El Bulli, closed in 2011. (Photo by Jaime Reina/AFP Photo)

People dodge waves in Sansha Township of Xiapu, southeast China's Fujian Province, July 10, 2015. China is on highest alert as super typhoon Chan-Hom approaches the eastern coast at high speeds. The National Meteorological Center issued a red alert on Friday morning for Chan-Hom, whose center was spotted 550 km southeast off the coast of Zhejiang Province at 5 a.m. (Photo by Jiang Kehong/Xinhua)