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)

Singer Rihanna prepares for a photoshoot with photographer Annie Leibovitz in Havana, Cuba, May 28, 2015. (Photo by Reuters/Stringer)

The Jet Propulsion Lab team's RoboSimian robot turns on a valve at a simulated disaster-response course during day one of the Defense Advanced Research Projects Agency (DARPA) Robotics Challenge finals in Pomona, California, June 5, 2015. (Photo by David McNew/Reuters)

Lukas Podolski of Koeln is challenged by Philipp Wollscheid of Nuernberg during the Bundesliga match between 1. FC Koeln and 1. FC Nuernberg at RheinEnergieStadion on April 3, 2011 in Cologne, Germany.

Mexico City resident Romina Montoya takes a playful selfie wearing a protective face mask over her eyes and nose, in Playa del Carmen, Quintana Roo state, Mexico, Wednesday, January 6, 2021. Concern is spreading that the critical winter holiday tourism success could be fleeting because it came as COVID-19 infections in both Mexico and the United States were reaching new heights. (Photo by Emilio Espejel/AP Photo)

Activists from the animal rights group PETA wearing bikinis and crocodile masks assist each other outside a store of the French fashion label Hermes in Sydney on March 4, 2021, as they protest against their use of crocodile skins and the recent purchases by Hermes and LVMH of crocodile farms in Australia's Northern Territory. (Photo by David Gray/AFP Photo)

A model presents a creation by LARHHA during the Code'41 Andalusian Fashion Week at the Amphitheatre of Italica in Seville on March 21, 2021. (Photo by Cristina Quicler/AFP Photo)

A woman on her hen day reacts as members of the public enjoy a drink in the Grassmarket as lockdown measures are eased on April 26, 2021 in Edinburgh, United Kingdom. Cafes, beer gardens, non-essential shops and museums are reopening in Scotland today as lockdown easing continues. (Photo by Jeff J. Mitchell/Getty Images)