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)

In this handout photograph received from Sumukha J.N on December 15, 2016, the newly-discovered spider Eriovixia Gryffindori sits on a leaf in the Kans in India's Western Ghats. (Photo by Sumukha J.N./AFP Photo)

Players in action during the Swamp Soccer Championships 2019 in Hyrynsalmi, Finland, 19 July 2019. The World Championship in swamp football is played annually on Vuorisuo bog in Hyrynsalmi. (Photo by Tomi Hanninen/EPA/EFE)

A Highland Cow at sunset on the edge of the Marlborough Downs, Wiltshire, United Kingdom on October 18, 2020. (Photo by David White/PictureExclusive)

British television presenters Trinny Woodall (centre right) and Susannah Constantine (centre) lead almost 900 women in throwing their old bras into the air in Rothwell town square in Rothwell, Northamptonshire on May 7, 2007. (Photo by Clara Molden – PA Images/PA Images via Getty Images)

Australian model Kate Fischer (Tziporah Malkah) poses with a Cointreau Ball to celebrate France’s founding anniversary in Sydney, Australia on July 14, 1996. (Photo by Getty Images)

A leaf from a sweetgum tree (Liquidambar styraciflua) lies on the grass at Godewaersvelde early October 27, 2017. (Photo by Philippe Huguen/AFP Photo)