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)

The Bridge “Rakotzbrücke” is pictured against trees in autumn colours in the the eastern German town of Kromlau November 4, 2014. (Photo by Hannibal Hanschke/Reuters)

Sunrise over St Mary's lighthouse north of Whitley Bay on the coast of north east England on Wednesday, May 19, 2021. (Photo by Owen Humphreys/PA Images via Getty Images)

A girl walks along former railway tracks in the so- called “Tunnel of Love”, surrounded by arches of intertwined trees, near the Ukrainian village of Klevan, Rivno region, on August 6, 2018. The tunnel of about five kilometres in length is a botanical phenomenon, which became a cult place for tourists and couples in love. The tourist legend says that wishes of couples in love will come true, if the couple passes through the tunnel. (Photo by Sergei Supinsky/AFP Photo)

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)

Before sunrise there is a “Turneresque” sky over the abbey at the picturesque Wiltshire, England market town of Malmesbury on June 11, 2023. (Photo by Terry Mathews/Alamy Live News)

A colourful sky before sunrise on Whitley Bay beach on December 21, 2015, as December could be the mildest across a large part of England since records began more than 350 years ago, forecasters have said. (Photo by Owen Humphreys/PA Wire)

European Space Agency astronaut Tim Peake will return home after a six-month long mission on the International Space Station,on June 18, 2016. Peake was the first British ESA astronaut to visit the ISS and captured hundreds of photographs of the Earth during his mission. Here: “Lots of sun-glint right now during our whole orbit – we haven't seen a sunset for over 3 days”, he wrote. (Photo by Tim Peake/ESA/NASA)