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)

Costumed participants are reflected in a woman's sunglasses during the Summer Carnival Street Parade, which travels through the streets of the center of Rotterdam, the Netherlands, 27 July 2019. Twenty floats participated in the parade with dance acts and lots of music. (Photo by Marco De Swart/EPA/EFE/Rex Features/Shutterstock)

A visitor is dwared between the wheels of BelAZ 450-ton dump truck (L) and BelAZ 360-ton dump truck (R) at the plant of Belarusian manufacturer of heavy trucks and equipment for earthmoving, BelAZ, in Zhodino, some 55 km from Minsk, Belarus, 27 August 2019. The company mostly delivers its products to CIS mining companies, mainly from Russia and Ukraine. (Photo by Tatyana Zenkovich/EPA/EFE/Rex Features/Shutterstock)

Take me away, deer, Russia. The Nenet people of Arctic Russia use reindeer and sledges as a prime mode of transport. The animals’ navigational ability means that in severe conditions they are sometimes the only hope of survival. (Photo by Kamil Nureev/Smithsonian Photo Contest)

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)

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)

A bolt of lighting strikes over Lewiston, Idaho, behind the Interstate Bridge that spans the Snake River into Clarkston, Wash., on the morning of Thursday, July 1, 2021. Multiple thunderstorms moved through the area on Wednesday evening into Thursday morning. (Photo by Pete Caster/Lewiston Tribune via AP Photo)

A boy kicks a football in Dudley Page Reserve as storm clouds gather over the city skyline on September 30, 2021 in Sydney, Australia. The Bureau of Meteorology has issued severe storm warnings for the city. (Photo by Mark Evans/Getty Images)