People observe a protest against a new citizenship law from a bus, in New Delhi, India, January 3, 2020. (Photo by Anushree Fadnavis/Reuters)

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 villager offers prayer to a dead body of an elephant, which is killed by lightning at atop of Bamuni hill in Assam's Nagaon district, on May 14, 2021. 18 wild elephants were found dead atop Bamuni Hills in Assam's Nagaon district today after lightning struck them during the showers in the area on May 12, 2021. At least 18 elephants are suspected to have been killed by lightning in northeastern India, officials said on May 13 as they launched a probe into the incident. (Photo by Biju Boro/AFP Photo)

This August 28, 2017 photo shows eight-year-old Indian girl Bharti performing a balancing act on a rope during a street show in Batala, India. Travelling Indian performers, who earn a meagre income from putting on shows on the streets, often scout areas to gather a large street audience who then give money on a collection plate at the end of the show. (Photo by Narinder Nanu/AFP Photo)

Mary Ellen Mark was an American photographer known for her photojournalism / documentary photography, portraiture, and advertising photography. She photographed people who were "away from mainstream society and toward its more interesting, often troubled fringes". Here: Amanda and her cousin Amy, Valdese, North Carolina, 1990. (Photo by Mary Ellen Mark)

Michael Kefalianos of Australia prepares backstage prior to the pre judging for the 2012 IFBB Australian Pro Grand Prix XII at The Plenary on March 17, 2012 in Melbourne, Australia. (Photo by Robert Cianflone/Getty Images)

Students with faces painted as Hindu goddess Kali, take part in a cultural event ahead of the Janmashtami festival, or the birth anniversary of Hindu Lord Krishna, inside a college in Mumbai, India on September 4, 2023. (Photo by Francis Mascarenhas/Reuters)

A devotee immerses an idol of elephant-headed Hindu god Ganesha in an artificial pond during Ganesh Chaturthi festival in Mumbai, India on September 20, 2023. (Photo by Aditya/NurPhoto/Rex Features/Shutterstock)