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)

Women take part in the desert trek “Rose Trip Maroc”, on November 1, 2019 in the erg Chebbi near Merzouga. The Rose Trip Maroc is a female-oriented trek where teams of three must travel through the southern Moroccan Sahara desert with a compass, a map and a topographical reporter. (Photo by Jean-Philippe Ksiazek/AFP Photo)

This undated handout image courtesy of the San Diego Zoo Wildlife Alliance shows “Pat”, a Pacific pocket mouse fondly named after actor Sir Patrick Stewart. A mouse named after “Star Trek” actor Patrick Stewart is officially the world's oldest in captivity, a US zoo has announced Pat the Pacific Pocket Mouse – the smallest species of mouse in North America – bagged the title when he hit nine years and 209 days old on February 8, 2023. (Photo by Ken Bohn/San Diego Zoo Wildlife Alliance via AFP Photo)

Migrants bathe in the Huixtla River, Chiapas state, Mexico, Tuesday, October 26, 2021, as they take a day of rest before continuing their trek across southern Mexico to the U.S. border. (Photo by Marco Ugarte/AP Photo)

Boys in ceremonial uniform at the civil wedding ceremony of American actress Grace Kelly and Rainier III, Prince of Monaco at the Prince's Palace of Monaco, 18th April 1956. Original publication: Picture Post - 8336 - The Hour Of Marriage - pub. 28th April 1956.

Clown/comedian/filmmaker Pierre Etaix attends The Academy Of Motion Picture Arts And Sciences' Presents “Pierre Etaix: The Laughter Returns” at AMPAS Samuel Goldwyn Theater on November 16, 2011 in Beverly Hills, California. (Photo by Valerie Macon/Getty Images)

Harry Sprinkle eats a meal at St. John's Bread and Life, a free meal service, on December 23, 2011 in the Brooklyn borough of New York City. St. John's Bread and Life serves approximately 2,200 meals per day; the organization has existed since 1982. (Photo by Andrew Burton/Getty Images)

Festival goers wear Australia day attire at Big Day Out 2012 at the Sydney Showground on January 26, 2012 in Sydney, Australia. (Photo by Mark Metcalfe/Getty Images)