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)

David Goffin of Belgium meets a koala during a promotional event for the Australian Open tennis tournament at Melbourne Park on January 17, 2018. (Photo by Fiona Hamilton/Reuters/Tennis Australia)

A couple take photographs alongside the National Monument on Calton Hill, Edinburgh on Wednesday January 5, 2022, ahead of First Minister Nicola Sturgeon's update to the Scottish Parliament on the Covid-19 situation as the Omicron variant sweeps across the country. (Photo by Jane Barlow/PA Images via Getty Images)

Ukrainian platoon commander Mariia talks on the phone in a position in the Donetsk region, Ukraine, Saturday, July 2, 2022. Ukrainian soldiers returning from the frontlines in eastern Ukraine’s Donbas region describe life during what has turned into a grueling war of attrition as apocalyptic. Mariia, 41, said that front-line conditions may vary depending on where a unit is positioned and how well supplied they are. (Photo by Efrem Lukatsky/AP Photo)

A Sotheby's employee poses with a “Return of the Jedi” promotional C-3PO Helmet 1983, estimated at £15,000-£25,000 created by George Lucas' visual effects company during a photocall at Sotheby's in London, Britain on December 6, 2019. (Photo by Thomas Mukoya/Reuters)

Camels graze in front of a spacecraft tracking station ahead of the Soyuz MS-10 upcoming launch at the Baikonur Cosmodrome, Kazakhstan, October 9, 2018. (Photo by Shamil Zhumatov/Reuters)

A fan of England cheers prior to the UEFA EURO 2020 quarter final match between Ukraine and England in Rome, Italy, 03 July 2021. (Photo by Mike Hewitt /EPA/EFE)

People are silhouetted while riding the Atmosfear double swing, which lifts riders more than 66 meters into the air while spinning at up to 70 km/h, at the Pacific National Exhibition at sunset in Vancouver, British Columbia, on Tuesday, August 31, 2021. (Photo by Darryl Dyck/The Canadian Press via AP Photo)