Members of the media film as a ranger performs a post mortem on the carcass of a rhino after it was killed for its horn by poachers at the Kruger national park in Mpumalanga province August 27, 2014. Rhino poachers in South Africa now risk giving themselves away when they shoot thanks to a high-tech, gunfire-detection system being piloted in the country's flagship Kruger National Park. The stakes are high, for rhinos are being slain in escalating numbers for their prized horns, alarming both conservationists and the government since wildlife in South Africa is an important tourist draw. (Photo by Siphiwe Sibeko/Reuters)

A protester clashes with a police officer in Athens' central Syntagma (Constitution) Square in this June 15, 2011 file photo. Greece triggered the regional financial crisis in 2009 when a far higher budget deficit than previously calculated emerged. The collapse of talks with creditors in Paris last November set off a month-long sequence of events leading to elections this week and proving Greece is still the region's weak link. The vote is expected to be won by Syriza, a far-left party opposed to the bailout, worrying investors and creditors alike. (Photo by Yannis Behrakis/Reuters)

An elderly man uses a fan to shade himself from the sun as he walks in a public park in Beijing, Tuesday, June 7, 2016. Thursday marks the Duanwu Festival, a public holiday in China celebrated with outdoor activities including dragon boat races. (Photo by Mark Schiefelbein/AP Photo)

Revellers dressed as zombies take part in an enactment of the running of the bulls a day before the start of the San Fermin festival in Pamplona, northern Spain, July 5, 2016. (Photo by Eloy Alonso/Reuters)

A fishmonger carries a shark on his motorcycle in Padang, West Sumatra, Indonesia August 25, 2016. (Photo by Iggoy el Fitra/Reuters/Antara Foto)

A walker has left a handprint on a snow- covered tree trunk on Grosser Feldberg mountain in the Taunus mountain range, Germany, 16 January 2017. (Photo by Frank Rumpenhorst/DPA)

A man waits with his camel to take part in a camel decoration competition at the Nagaur Cattle Fair, where animals like camels, cows, horses, and bulls are brought to be sold or traded, in Nagaur, in the desert state of Rajasthan, India February 2, 2017. (Photo by Himanshu Sharma/Reuters)

A woman holds newly designed Indonesia Rupiah banknotes after exchanging her old bills at a Bank Indonesia mobile bank in Jakarta, Indonesia December 19, 2016. (Photo by Fatima El-Kareem/Reuters)