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 woman gets tattooed at The Great British Tattoo Show at Alexandra Palace on May 24, 2014 in London, England. (Photo by Tristan Fewings/Getty Images for Alexandra Palace)

Gothic enthusiast poses during the annual Wave-Gotik-Treffen music festival on May 26, 2012 in Leipzig, Germany. The event began in the 1990s and has since grown into one of the biggest gatherings of Goth scene followers in Europe with around 20,000 participants. (Photo by Adam Berry)

Bonhams expert Michaela Vergottis holds a yellow Jade Chinese Imperial Sceptre on May 9, 2011 in London, England. The piece which is thought to have been taken by British Troups during the Boxer Rebellion is expected to fetch between £800,000 – 1.2 M GBP when it goes on sale at the “Chinese Art” sale at Bonham's auction house on May 12, 2011. (Photo by Dan Kitwood/Getty Images)

A newly-born male baby elephant, who so far does not have a name, walks with his mother Temi during his first venture outside at their enclosure at the Tierpark Hellabrun zoo on May 12, 2011 in Munich, Germany. The baby elephant was born at the zoo on May 6. (Photo by Alexander Hassenstein/Getty Images)

Participants arrive at the finish line during the annual Maldon Mud Race in Maldon, east England on May 7, 2017. Originating in 1973, the race involves competitors racing around a course through the River Blackwater in Essex at low tide. (Photo by Daniel Leal-Olivas/AFP Photo)

Actress and model Charlotte McKinney attends the grand opening of NightSwim at Encore Beach Club at Wynn Las Vegas on May 5, 2017 in Las Vegas, Nevada. (Photo by David Becker/Getty Images for Wynn Las Vegas)

Vian Salman, center, smiles with fellow contestants after she was crowned the new Miss Iraq during the Miss Iraq contest in Baghdad, Iraq, Thursday, May 25, 2017. (Photo by Karim Kadim/AP Photo)