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)

A bloodied man who carried dead and wounded, speaks on the phone at the site of a suicide attack an explosion that struck a protest march, in Kabul, Afghanistan, Saturday, July 23, 2016. Witnesses in Kabul say that an explosion causing multiple casualties struck the march by members of Afghanistan’s largely Shiite Hazara ethnic minority group, who were demanding that a major regional electric power line be routed through their impoverished home province. (Photo by Omar Sobhani/Reuters)

Residents carry an injured woman rescued from a collapsed house in Funing county in Yancheng city of eastern China's Jiangsu Province on Thursday June 23, 2016. A powerful tornado hit Thursday, with reports of dozens killed and large numbers of buildings destroyed in the eastern Chinese province of Jiangsu, according to state media. (Photo by Chinatopix via AP Photo)

An aerial view shows people touring between the large-scale ice sculptures at the 18th Harbin Ice and Snow World during its trial run opening to public in Harbin city, Heilongjiang province, China, 21 December 2016. Some 180,000 cubic meters of ice and 150,000 cubic meters of snow were used to build the 800,000-square-meter ice wonderland. The 33rd Harbin International Ice and Snow Festival will kick off on 05 January 2017 that will last about three months. (Photo by Tian Weitao/EPA)

A combination picture shows Will Adam, 14, snowboarding down a street on Beacon Hill during a large winter blizzard in Boston, Massachusetts, United States January 27, 2015 (top), and a woman looking at her phone as she walks down the same street June 13, 2015. Outdoor scenes in Boston show local residents enjoying balmy weather amid lush greenery as the summer solstice approaches on 21 June. The very same locations suffered heavy snowstorms last winter, with snow ploughs, skiers and snowboarders battling the drifts. Boston got 275.8 cm of snow over the winter, the most since 1872, when records began. A few months after the snowstorms, Brian Snyder revisited the same places and shot pictures at exactly the same locations. (Photo by Brian Snyder/Reuters)

A boy looks inside the skull of a Tyrannosaurus Rex replica at the Egidio Feruglio Museum in Trelew, Argentina, in this May 18, 2014 file photograph. Scientists on July 28, 2015 unveiled a comprehensive analysis of the teeth of the group of carnivorous dinosaurs called theropods, which include the Tyrannosaurus Rex, detailing a unique serrated structure that let them chomp efficiently through the flesh and bones of large prey. (Photo by Maxi Jonas/Reuters)

A pro-abortion activist with a Venus symbol painted on her face listens to a speech outside of Congress after the presentation of an abortion bill in Buenos Aires, Argentina, Tuesday, March 6, 2018. Under heavy pressure by women's groups that have taken to the streets in large numbers in recent years, over 70 legislators presented an abortion bill that will be first be discussed in several committees of the lower chamber. (Photo by Victor R. Caivano/AP Photo)

In this Friday, August. 17, 2018, photo, a North Korean waitress prepares to serve dinner to Chinese tourists at the Pegaebong hotel in Samjiyong in North Korea. Chinese businesspeople and tourists are once again flowing over the borders – several large tourist groups were in Samjiyon last week – and South Korean officials are seriously considering ways to help the North improve its roads and railways. (Photo by Ng Han Guan/AP Photo)