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)

The fourth annual BigPicture Natural World Photography Competition aims to celebrate the diversity of life on Earth, and encourages people to protect and conserve it. Here: “The Salmon Catchers”. Terrestrial Wildlife. To capture this view of a mother grizzly bear and her cub, photographer Peter Mather set up a camera trap on a log that he knew the bears tended to traverse while fishing for salmon, in the Yukon River watershed in Canada. (Photo by Peter Mather/BigPicture Natural World Photography Competition 2017)

Volunteers throw a mixture of water, neem herb and turmeric as an alleged natural disinfectant on a street in a residential area during a government-imposed nationwide lockdown as a preventive measure against the COVID-19 coronavirus, in Chennai on April 7, 2020. (Photo by Arun Sankar/AFP Photo)

A worker displays paper pandas created by French artist Paulo Grangeon in front of the Grand Palace in Bangkok, Thailand, Friday, March 4, 2016. The exhibit is part of the World Wide Fund's project where the 1600 paper pandas symbolize the last pandas still present in nature.(Photo by Sakchai Lalit/AP Photo)

Dead leaf or almost by Guilhem Duvot. Taken in Nován Stráž, Slovakia. Describe what is pictured? A dead leaf grasshopper. How does this image fit with the theme of the competition? The perfect camouflage – nature is amazing. I saw the grasshopper only because it jumped. (Photo by Guilhem Duvot/Royal Society of Biology)

An alligator and his reflection seen in the Wakodahatchee Wetlands in Delray Beach, Florida on May 2, 2024. The wetlands attract nature lovers and wildlife photographers and are home to more than 140 bird species and a variety of other wildlife. (Photo by Ronen Tivony/ZUMA Press Wire/Rex Features/Shutterstock)

A field of poppies in flower in Great Massingham, Norfolk, UK on Tuesday, June 25, 2024. The field has been rewilded by the landowner, with the soil being ploughed and harrowed before being left for nature to run its course with the result being a huge sea of red poppies. (Photo by Joe Giddens/PA Images via Getty Images)