A dead red-tailed monkey hangs by its tail above the ground, in order to keep it away from ants, in the forest near the city of Mbandaka, Democratic Republic of the Congo, April 5, 2019. Bushmeat hunters are emptying Central Africa's forests at a high rate, researchers say. A growing appetite for wild meat in cities has ramped up the scale of hunting. Research shows around 6 million tonnes of bushmeat are sourced annually from the Congo Basin, whose forest spans across six countries and is second in size only to the Amazon. (Photo by Thomas Nicolon/Reuters)

A woman waits at a polio immunisation health centre, in Maiduguri, Borno State, Nigeria, August 29, 2016. Nigeria's military has liberated large swathes of land from Boko Haram but a ride with an army convoy, all guns firing for fear of ambush, shows how far the northeast is from normality after a brutal Islamist insurgency that has displaced millions. (Photo by Afolabi Sotunde/Reuters)

A boat commutes across the Mekong river in Phnom Penh on August 8, 2014. The Mekong is the world's twelth longest river running from the Tibetan Plateau through China's Yunnan province, Myanmar, Laos, Thailand, Cambodia and Vietnam. (Photo by Tang Chhin Sothy/AFP Photo)

Undated UK Ministry of Defence handout photo of an RAF Tornado GR4 which has been painted in Gulf War “desert pink” paint scheme to honour the aircraft type's almost continuous operational service since the Royal Air Force helped liberate Kuwait from Saddam Hussein's forces, taken by SAC Rose Buchanan, which has been shortlisted for the general public to pick their favourite RAF Image of the Year. (Photo by SAC Rose Buchanan/MoD Crown Copyright/PA Wire)

Hillary Clinton waves to a selfie-taking crowd at a recent campaign event in Orlando, Florida on September 26, 2016. (Photo by Barbara Kinney/Hillary for America)

Life-size sеx dolls are displayed during the 2016 AVN Adult Entertainment Expo at the Hard Rock Hotel & Casino on January 20, 2016 in Las Vegas, United States. (Photo by Gabe Ginsberg/FilmMagic)

A woman made up as a skull participates in Day of the Dead festivities in Mexico City, Thursday, October 27, 2016. The holiday honors the dead as friends and families gather in cemeteries to decorate their loved ones' graves and hold vigil through the night on Nov. 1 and 2. (Photo by Marco Ugarte/AP Photo)

Kale grows at Kajodlingen farm in Gothenburg, Sweden, September 28, 2016. They are doing it on the rooftops, on tower block balconies and even on a disused railway: Swedes have discovered a passion for urban gardening as a way of growing fresh food and getting back in touch with nature. Part of a global movement, an increasing number of Swedish city-dwellers are growing their own in window boxes and allotments or are visiting public gardens built in or on industrial or office spaces. (Photo by Maxim Shemetov/Reuters)