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)

American actress Caylee Cowan attends the OK! Magazine NYFW Party at PhD, Dream Downtown Hotel Rooftop on September 10, 2019 in New York City. (Photo by Stephen Lovekin/OK! Magazine/Rex Features/Shutterstock)

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)

(L-R) Canadian actor Patrick J. Adams as Michael Ross and American member of the British royal family and a former actress Meghan Markle as Rachel Zane at “Breakfast, Lunch and Dinner”, Episode 402 in April 2014. (Photo by Ian Watson/USA Network/NBCU Photo Bank/NBCUniversal via Getty Images)

A green jumping spider (Lyssomanes viridis), in a forested area of Cerro de la Muerte, in San Jose, Costa Rica, 20 May 2025. International Day for Biological Diversity is celebrated every 22 May around the world. (Photo by Jeffrey Arguedas/EPA/EFE)

A koala named Lisa from Pappinbarra recovers from burns at The Port Macquarie Koala Hospital on November 29, 2019 in Port Macquarie, Australia. Volunteers from the Koala Hospital have been working alongside National Parks and Wildlife Service crews searching for koalas following weeks of devastating bushfires across New South Wales and Queensland. Koalas rescued from fire grounds have been brought back to the hospital for treatment. An estimated million hectares of land has been burned by bushfire across Australia following catastrophic fire conditions in recent weeks, killing an estimated 1000 koalas along with other wildlife. (Photo by Nathan Edwards/Getty Images)

Models pose in designs from May Quant's collection on a street in London, England, on October 16, 1969. Grania, left, wears the "Shimmy Shimmy," a white rayon dress over matching pants with a shawl. Baba, center, wears "Razzamatazz," a jumpsuit featuring plastic sequins in blue, silver and red on nylon. Linda wears "Muffit," a pink minidress with an old English style floppy mobcap. (Photo by AP Photo)

Retired 90 year old Frank Foss of St. Petersburg, Florida, with his home made banjo, made from a frying pan, a length of wood and some strings. (Photo by Fox Photos/Getty Images). 2nd July 1972