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 helicopter of the Food and Agriculture Organization of the United Nations (FAO) flies through millions of Locusts as spreads pesticide to fight against a swarm of locusts threatening to reach Amparihibe village on May 7, 2014 in Tsiroanomandidy, Madagascar. FAO mission is to fight the locust's swarm with an insecticide. (Photo by AFP Photo/RIJASOLO)

The giant inflatable Rubber Duck installation by Dutch artist Florentijn Hofman floats on the Parramatta River, as part of the 2014 Sydney Festival, in Western Sydney, January 10, 2014. The creation is five stories tall and five stories wide and has been seen floating in various cities around the world since 2007. (Photo by Jason Reed/Reuters)

These portraits reveal the incredibly humanlike expressions of a variety of apes.Through piercing eyes and finite facial details, the intimate photographs show the animals looking angry, sad, delighted and pensive. They are the works of Manuela Kulpa – an IT consultant and keen photographer from near Cologne, Germany – who shot the apes predominantly at zoos across Austria, Belgium, the Czech Republic, Germany and the Netherlands. Here: Bonobo, Azibo. (Photo by Manuela Kulpa/Caters News)

Performers take part in a parade during the annual Cervantes market (Mercado Cervantino) in the hometown of famous Spanish writer Miguel de Cervantes, Alcala de Henares, Spain, October 9, 2015. The Mercado Cervantino, which represents a market and fair from the 16th and 17th centuries, takes place in the city's historic centre and commemorates Miguel de Cervantes' baptism, which took place on October 9, 1547. (Photo by Susana Vera/Reuters)

A thirsty timber wolf, Lithuania, 2018. (Photo by Erikas Plucas/Alamy Stock Photo)

A man who was set on fire by people accusing him of stealing during a rally against Venezuela's President Nicolas Maduro runs amidst opposition supporters in Caracas, Venezuela, May 20, 2017. (Photo by Marco Bello/Reuters)

Members of the Pussyfooters dance at the Krewe of Cleopatra Mardi Gras parade in New Orleans, Friday, February 2, 2018. Mardi Gras season is kicking into high gear with a slew of major parades throughout New Orleans. Although Carnival season officially began Jan. 6, the festivities really kick into high gear the two weekends ahead of Fat Tuesday. This year Fat Tuesday is Feb. 13. (Photo by Gerald Herbert/AP Photo)