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

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)

France's Alize Cornet falls down during her women's singles tennis match against Kazakhstan's Elena Rybakina on the fourth day of the 2023 Wimbledon Championships at The All England Tennis Club in Wimbledon, southwest London, on July 6, 2023. (Photo by Glyn Kirk/AFP Photo)

This is the moment fog rolls through a valley making trees disappear as if covered by giant waves in a sea. The fog was rolling in over the sub-alpine mountain range of the Jura Mountains in Switzerland, February 2023. (Photo by Rainer Awiszus-Emser/Solent News & Photo Agency)

Decaying fishing trawlers known collectively as The Fleetwood Wrecks, are seen at low tide on the banks of the River Wyre in Fleetwood, Britain on September 26, 2023. (Photo by Lee Smith/Reuters)

Nick Bull captured the Geminid meteor shower above Stonehenge in Wiltshire, UK on December 14, 2023. (Photo by Nick Bull/Picture Eexclusive)

Waves breaking at Killiney Beach, Co Dublin, Ireland on Sunday, October 20, 2024. (Photo by Stephen Collins/Collins Photos)

Australian ballet dancers rehearse their moves on Whitehaven Beach on June 11, 2010 on Hamilton Island, Australia. (Photo by James Morgan/Hamilton Island via Getty Images)