Global wildlife populations will decline by 67% by 2020 unless urgent action is taken to reduce human impact on species and ecosystems, warns the biennial Living Planet Index report from WWF (World Wide Fund for Nature) and ZSL (Zoological Society of London). From elephants to eels, here are some of the wildlife populations most affected by human activity. Here: The maned wolf is among the large mammals in the Brazilian Cerrado that are threatened by the increasing conversion of grasslands into farmland for grazing and growing crops. (Photo by Ben Cranke/Nature Picture Library/Alamy Stock Photo)

Manman Luk, a freelance model and make up artist, poses inside her 100-square-foot (9-square-metre) sub-divided unit, paying a monthly rent of HK4,700 ($606) in Hong Kong, China January 6, 2017. (Photo by Bobby Yip/Reuters)

Wakodahatchee wetlands, Delray Beach, Florida, US. Equipped with sinewy necks and spear-like bills, great blue herons can lunge with fearsome speed to strike their aquatic prey. Adults will also employ rapid stabbing motions as one aspect of their complex courtship displays; they’re seemingly dangerous moves, but fitting to the intensity of mating season. (Photo by Melissa Rowell/Audubon Photography Awards)

Two wolfhounds take part in a dogfight in a stadium in the Kyrgyzstan capital Bishkek on November 5, 2017, during fights organized by a local breeders aiming to improve the Asian Shepherd breed, organizers said. (Photo by Vyacheslav Oseledko/AFP Photo)

Artist Pyotr Pavlensky sits on the wall enclosing the Serbsky State Scientific Center for Social and Forensic Psychiatry after he cut off a part of his earlobe during his protest action titled “Segregation” in Moscow October 19, 2014. Pavlensky protested against the usage of forensic psychiatry for politically motivated purposes. He cut off his earlobe to demonstrate how authorities could “cut off” an unwanted individual from society by using psychiatric and medical diagnosis to forcefully send a person to a penitentiary hospital, according to Pavlensky. (Photo by Maxim Zmeyev/Reuters)

Christie Brinkley and Ashley Graham pose after Lifetime's American Beauty Star Season 2 Live Finale at Manhattan Center on March 27, 2019 in New York City. (Photo by Mike Coppola/Getty Images for Lifetime)

Photographer Mihaela Noroc travelled the world from Ethiopia to the US and from Guatemala to France in search of natural and authentic beauty. She introduces some of the inspiring women she met on her journey. Here: Ecuador. “More and more tribes of Amazonia are starting to adopt modern clothes for everyday life. But they are still keeping their traditional clothes for important events. I photographed this young woman in her wedding outfit”. (Photo by Mihaela Noroc/The Guardian)

A model displays the collection of Italian luxury brand Diesel at its China's first flagship shop unveiling ceremony, at Henglong Plaza on November 26, 2005 in Shanghai, China. (Photo by China Photos/Getty Images)