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)

Icelandic horses play in their paddock at a stud farm in Wehrheim near Frankfurt, Germany, as a mist rolls in on Thursday, August 5, 2021. (Photo by Michael Probst/AP Photo)

Wakodahatchee wetlands, Delray Beach, Florida, US. Equipped with sinewy necks and spear-like bills, great blue herons can lunge with fearsome speed to strike their aquatic prey. Adults will also employ rapid stabbing motions as one aspect of their complex courtship displays; they’re seemingly dangerous moves, but fitting to the intensity of mating season. (Photo by Melissa Rowell/Audubon Photography Awards)

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)

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)

Sunrise in the New Forest near Lyndhurst in Hampshire, UK this morning, August 15, 2024. (Photo by Cenk Albayrak-Touye/Picture Exclusive)

Crowds look on as Xolo the Giant Dog, one of the giant Royal De Luxe street puppets taking part in Liverpool's World War I centenary commemorations, walks through the streets of Liverpool on July 25, 2014 in Liverpool, England. French street theatre company Royal de Luxe are putting on a show throughout the city as part of Liverpool's World War I centenary commemorations from July 23-27. The giant puppet grandmother has slept in the hall for two days as part of “Memories of August 1914”. As the giants tour the city the Little Girl Giant and her dog Xolo will meet up with the giant Grandmother telling the story of life leading up to World War One. (Photo by Christopher Furlong/Getty Images)

An anti-government protester wearing a Guy Fawkes mask stands with a shield near flames from molotov cocktails thrown at a water cannon by anti-government protesters during riots in Caracas in this April 20, 2014 file photo. (Photo by Jorge Silva/Reuters)