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)

In this April 2, 2016 photo, dusty sculptures made of cast-off baby dolls sit in an open-air museum and art workshop off a trash-strewn street cutting through some of the poorest neighborhoods in Port-au-Prince, Haiti. They were created by Haitian artists called Atis Rezistans who have become celebrated in the international art world by creating sculptures out of scrapped car parts, old wood, discarded toys and even human skulls found scattered outside crumbling mausoleums. (Photo by David McFadden/AP Photo)

In this June 29, 2016 file photo, boats docked at Central Marine in Stuart, Fla., are surrounded by blue green algae. The 153-mile-long Indian River Lagoon has been plagued by harmful algae blooms. Water quality testing data analyzed by the AP showed the average phosphorous level – a byproduct of fertilizers and human waste that algae thrive on, rose nearly 75 percent between 2000 and 2016. (Photo by Greg Lovett/The Palm Beach Post via AP Photo)

A petitioner with her grievances written on her clothes walks along a street in Beijing Tuesday, December 22, 2015. After months behind bars, Pu Zhiqiang, one of China's most prominent human rights lawyers, left a detention center Tuesday after receiving a suspended prison sentence in a case involving online comments critical of the ruling Communist Party. (Photo by Ng Han Guan/AP Photo)

Sugar gliders, Candy and Popcorn, enjoy their favourite food, Nectar, at Wild Life Sydney Zoo on February 14, 2017 in Sydney, Australia. The treat made up of honey, high protein baby cereal and egg yolks is the human equivalent to chocolate to the Sugar Gliders. St. Valentine's Day or the Feast of Saint Valentine began as a celebration of the early Christian Saint Valentinus. From the 18th Century onwards it has steadily transformed into a celebration of romantic love and sentiment in many countries around the world. (Photo by James D. Morgan/Getty Images)

A dog is worshiped during Tihar or Diwali festival in Kathmandu, Nepal on November 12, 2023. Nepali people worship dogs, dedicated solely to the human's most devoted friend and guardian on second day of Tihar fesival. “Tihar” the Hindu festival of flowers and lights, is celebrated for five days. (Photo by Sunil Sharma/ZUMA Press Wire/Rex Features/Shutterstock)

Iraqi Kurds carry fire torches as they celebrate Nowruz Day, a festival marking the first day of spring, Kurdish and Persian New Year in Akre, Iraq on March 20, 2024. Newroz or Nowruz means “new day” in Persian, and is celebrated to mark the arrival of spring and the first day of the Iranian calendar. It is widely celebrated in Persian and neighboring regions and is recognized on UNESCO's Intangible Cultural Heritage of Human List. (Photo by Ismael Adnan/SOPA Images/Rex Features/Shutterstock)

British sculptor Laurence Edwards' striking bronze figures, Walking Men, at Blenheim Palace in Oxfordshire, UK on April 9, 2024. The 8ft tall figures are seen to be anti-heroic and seem to have come from the earth itself. Branches, leaves and clods of clay are woven through them, making it unclear where human and ground begin and end. (Photo by Pete Seaward/South West News Service)