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)

Two wolfhounds take part in a dogfight in a stadium in the Kyrgyzstan capital Bishkek on November 5, 2017, during fights organized by a local breeders aiming to improve the Asian Shepherd breed, organizers said. (Photo by Vyacheslav Oseledko/AFP Photo)

A farmers carries baskets of salt during a harvest in the the salt production process August 13, 2009 in Sumenep on Madura island, Indonesia. (Photo by Ulet Ifansasti/Getty Images)

Norway's Karsten Warholm celebrates winning the men's 400m hurdles at the Diamond League in London, July 21, 2018. (Photo by Andrew Boyers/Action Images via Reuters)

An old toilet is displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. The exhibition focuses on how the toilet has changed our daily lives and discovers what the most environment-friendly and ideal toilet is. (Photo by Keith Tsuji/Getty Images)

Larsa Pippen leaves little to the imagination in a VERY racy warrior costume as she joins Shanina Shaik at Paris Hilton's Halloween bash in Beverly Hills, CA. on October 24, 2019. (Photo by Backgrid USA)

Gina Di Meo, journalist from ANSA sits during a media preview of Summit at One Vanderbilt in New York, October 1, 2021. The Summit viewing deck is spread across the top four floors on One Vanderbilt in Manhattan, the fourth tallest building in the city. (Photo by Timothy A. Clary/AFP Photo)

An aerial view of the figure of a Catrina skull made with 18,000 Cempasuchil flowers (Mexican marigold) is on display at the Church of Santa Prisca as part of Day of the Dead celebrations, in Taxco, Mexico on October 27, 2021. (Photo by Daniel Cardenas/Anadolu Agency via Getty Images)