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)

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)

Joel said documenting the Kazakh nomad summer migration was really an epic journey – a time travel journey – and at the same time was possible to get an understanding of how the balance of nature is still possible in Altai Mountains, Mongolia, June 2015. (Photo by Joel Santos/Barcroft Images)

16-year-old panda, Ye Ye, rests in an enclosure at the Wolong Nature Reserve, a conservation center that trains pandas for release into the wild. This image was published in the August 2016 National Geographic magazine as part of the “Pandas Gone Wild” story. (Photo by Ami Vitale/National Geographic Creative)

A golden lion tamarin monkey holds its newly born baby at a zoo in Jerusalem, Thursday, March 22, 2018. Golden lion tamarins are among the rarest animals in the world, according to the World Wildlife Fund. It is listed as endangered according to the International Union for Conservation of Nature. (Photo by Sebastian Scheiner/AP Photo)

Wildlife agency rangers rescue a Malayan tapir, an endangered species on the International Union for Conservation of Nature (IUCN) Red List, after it fell into a villager's fish pond in Pekanbaru, Riau on April 20, 2021. (Photo by Wahyudi/AFP Photo)