A South Sudanese People Liberation Army (SPLA) soldier patrols the streets in Malakal on January 21, 2014. (Photo by Harrison Ngethi/AFP Photo)

Two men fight in San Jose, Costa Rica, during the Women's Day on March 8, 2014. (Photo by Jeffrey Arguedas/EFE/SIPA Press)

A giant river otter, the world's largest otter species, looks out of its enclosure at the newly completed River Safari in Singapore, on March 25, 2013. (Photo by Wong Maye-E/Associated Press)

Gelada baboons (Theropithecus gelada) play in their enclosure at the Zoo in Zurich, Switzerland, Wednesday, May 15, 2013. (Photo by Steffen Schmidt/Keystone/AP Photo)

Revellers pose during the 24th Street Parade dance music event in Zurich, August 29, 2015. (Photo by Arnd Wiegmann/Reuters)

In a photo taken on July 29, 2018 instructor Kim Ju Yang (20) holds a North Korean- made assault rifle as she poses for a portrait at the Meari shooting range in Pyongyang. The Meari shooting range offers customers the opportunity to shoot a number of North Korean and foreign- made firearms, most of which have been modifed to fire .22 calibre ammunition costing one US dollar per round. (Photo by Ed Jones/AFP Photo)

Girls play with live Teacup pigs, a rare pet in the country, at the start of celebrations leading to the Lunar New Year, Friday, February 1, 2019 at Lucky Chinatown Plaza mall in Manila, Philippines. The upcoming Year of the Pig represents abundance, diligence and generosity. (Photo by Bullit Marquez/AP Photo)

Commuters interact with an elephant as he rests in a public road ahead of the annual Perahera festival of the historic Gangaramaya Temple in Colombo on February 18, 2019. Some 50 elephants, most of them from the central area of Kandy along with thousands of traditional drummers, dancers, and monks have gathered in the Sri Lankan capital to participate in the city's biggest two-day annual Buddhist Navam procession, scheduled for February 18-19. (Photo by Ishara S. Kodikara/AFP Photo)