Boats of fishermen are seen on the dried Poopo lakebed in the Oruro Department, south of La Paz, Bolivia, December 17, 2015. Lake Poopo in Bolivia, the Andean nation's formerly second largest after the famed Titicaca, has dried up entirely. With the water now gone, animals have died off in the millions, according to studies. And the local families, having lost much of their sustenance, have been forced to migrate. (Photo by David Mercado/Reuters)

Members of the Old Surrey Burstow and West Kent Hunt ride to Chiddingstone Castle for the annual Boxing Day hunt in Chiddingstone, south east England December 26, 2014. Since a ban stopped fox hunting with hounds, hunts continued with dogs chasing down a pre-laid scented trail instead of a fox. (Photo by Luke MacGregor/Reuters)

Naga Sadhus or Hindu holy men, smeared with ash, drink tea inside their makeshift camps near the confluence of river Ganges and the Bay of Bengal, ahead of Makar Sankranti festival at Sagar Island, south of Kolkata January 13, 2015. Hindu monks and pilgrims are making their annual trip to Sagar Island for the one-day festival of “Makar Sankranti” on Wednesday. (Photo by Rupak De Chowdhuri/Reuters)

An instructor guides a student from the General Yermolov Cadet School as she aims with a gun during a field exercise outside the south Russian city of Stavropol January 24, 2015. The General Yermolov Cadet School in Stavropol is a state-run institution that teaches military and patriotic classes in addition to a normal syllabus. (Photo by Eduard Korniyenko/Reuters)

A participant in costume eats a sandwich after a Halloween parade in Kawasaki, south of Tokyo, October 26, 2014. More than 100,000 spectators turned up to watch the parade, where 2,500 participants dressed up in costumes, according to the organiser. (Photo by Yuya Shino/Reuters)

A student from the General Yermolov Cadet School takes part in weapons training during a two-day field exercise near the village of Sengileyevskoye, just outside the south Russian city of Stavropol April 13, 2014. The General Yermolov Cadet School in the southern Russian city of Stavropol is a state-run institution that teaches military and patriotic classes in addition to a normal syllabus. (Photo by Eduard Korniyenko/Reuters)

A girl watches as Saen Dao, an eight-year-old female asian elephant, and her mahout perform underwater during a show at the Khao Kheow Open Zoo in Chonburi south of Bangkok on June 1, 2017. (Photo by Roberto Schmidt/AFP Photo)

Men slide in the mud during the Boryeong Mud Festival at Daecheon Beach in Boryeong, South Korea, Saturday, July 22, 2017. The 20th annual mud festival features mud wrestling and mud sliding. (Photo by Ahn Young-joon/AP Photo)