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)

Costume details featuring Joao Candido, a black sailor who led a revolt against the physical punishment of Brazilian Navy soldiers at the beginning of the 20th century, lie inside the Paraíso do Tuiuti Samba school at the Samba City complex in Rio de Janeiro, Brazil, Tuesday, January 16, 2024. Samba schools are gearing up for this year's Carnival, scheduled from Feb. 9-17. (Photo by Bruna Prado/AP Photo)

A jaguar (Panthera onca) growls at the Mata Ciliar association, an organization for the conservation of biodiversity, in Jundiai, Sao Paulo state, Brazil on May 29, 2025. Twenty-five pumas and ten jaguars are currently recovering at the Brazilian Center for the Conservation of Neotropical Felines at Mata Ciliar, a site as large as 40 football fields where monkeys, wild dogs, maned wolves, ocelots, and other regional animals are also rehabilitated. (Photo by Nelson Almeida/AFP Photo)

Brazilian model and television personality Alessandra Ambrosio attends Alessandra Ambrosio And Darren Dzienciol's Horror In The Hills on October 31, 2019 in Beverly Hills, California. (Photo by Rochelle Brodin/Getty Images)

Iguazu Falls are waterfalls of the Iguazu River on the border of the Brazilian state of Paraná and the Argentinian province of Misiones. The falls divide the river into the upper and lower Iguazu. The Iguazu River rises near the city of Curitiba. It flows through Brazil for most of its course. Below its confluence with the San Antonio River, the Iguazu River forms the boundary between Argentina and Brazil.

Singer Whitney Houston performs onstage at the 2009 American Music Awards at Nokia Theatre L.A. Live on November 22, 2009 in Los Angeles, California. (Photo by Kevork Djansezian/Getty Images)

Singer Donni Rai arrives at the 48th Annual Grammy Awards at the Staples Center on February 8, 2006 in Los Angeles, California. (Photo by Stephen Shugerman/Getty Images)

American singer Ashley Nicolette Frangipane, known professionally as Halsey shows off her Innovation Award in early March 2022. (Photo by iamhalsey/Instagram)