A butterfly flies into the jaws of a crocodile inhabiting the Tarcoles River, the most polluted basin in Central America and one of the most polluted in Latin America, in the place of Tarcoles, province of Puntarenas, Costa Rica, 05 June 2018. Costa Rica, a country recognized worldwide for its environmental policies, seeks to be a leader in the replacement of single-use plastic with renewable and compostable alternatives, despite its lag in terms of recycling and integrated waste management. (Photo by Jeffrey Arguedas/EPA/EFE)

A man pulls a cart with collapsed cardboard boxes past boutiques in the Sinchon district in Seoul, May 5, 2015. (Photo by Thomas Peter/Reuters)

Female of pygmy hippopotamus called Malaya from Netherlands in zoo in Dvur Kralove nad Labem, Czech Republic, February 22, 2016. (Photo by David Tanecek/CTK via ZUMA Press)

Female Siberian tiger Dasha yawns in the new enclosure at the zoo in Duisburg, Germany, 30 March 2016. The new facility is three times larger than the old one and will be opened to the public on the same day. (Photo by Roland Weihrauch/EPA)

A hippopotamus performs during a show at the circus in Krasnoyarsk, Siberia, Russia, July 7, 2016. (Photo by Ilya Naymushin/Reuters)

A seafood vendor moves a giant swordfish to his stall at a market in Qingdao, Shandong province, China, September 12, 2015. The 4.1-metre-long (13.5 feet) swordfish, weighed about 309.5 kilograms (682 lbs), was caught by local fishermen on Friday, local media reported. (Photo by Reuters/Stringer)

A keeper feeds a four-week-old jaguar while presenting it to the media, at a zoo in Ciudad Juarez, Mexico, October 14, 2015. (Photo by Jose Luis Gonzalez/Reuters)

A man in “Red Army” garb hits the pavement during a simulated attack during a re-staging of part of the Long March in Jinggangshan September 14, 2017. The scene brings alive an extraordinary chapter in China's history that established the supremacy of Chairman Mao Zedong and the Communist Party. Deep in the mountains of Jinggangshan in the southeastern province of Jiangxi, a classroom of bank tellers participates in an ideological boot camp that plays into Chinese President Xi Jinping's drive to further consolidate his grip on power. (Photo by Thomas Peter/Reuters)