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)

People clash with Venezuelan National Guards as they try to cross the border to Colombia over the Francisco de Paula Santander international bridge in Urena, Venezuela December 18, 2016. (Photo by Carlos Eduardo Ramirez/Reuters)

Jason Ramsay and Amy Laverty, from Arbroth, Scotland, pose beside a large Christmas tree at Bondi Beach on December 25, 2016 in Sydney, Australia. Bondi Beach is a popular tourist destination on Christmas Day. (Photo by Don Arnold/Getty Images)

Stanford golfer Rose Shang smiles towards her teammates after winning the NCAA college women's golf championship at Grayhawk Golf Club, Monday, May 22, 2023, in Scottsdale, Ariz. (Photo by Matt York/AP Photo)

Samba dancers outside Woolwich station celebrate the opening of the Elizabeth Line in London, England on May 23, 2022. Originally due to open in December 2018, the £18.8bn railway links Reading and Essex via central London. (Photo by Jill Mead/The Guardian)

Members of the Indian Army Service Corps (ASC) team known as the “Tornadoes” display their motorbike skills during Independence Day celebrations in Bangalore, India, 15 August 2023. India is marking the 77th anniversary of its independence from British rule. (Photo by Jagadeesh N.V./EPA)

People watch the Pikachu parade which is a part of the 2023 Pokémon World Championships, at Grand Mall Park in Yokohama on August 11, 2023. (Photo by Philip Fong/AFP Photo)

People pose for photographs in the wind during Typhoon Saola in Tseung kwan O, in Hong Kong on Saturday, September 2, 2023. Typhoon Saola made landfall in southern China before dawn Saturday after nearly 900,000 people were moved to safety and most of Hong Kong and other parts of coastal southern China suspended business, transport and classes. (Photo by Billy H.C. Kwok/AP Photo)