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 boy looks inside the skull of a Tyrannosaurus Rex replica at the Egidio Feruglio Museum in Trelew, Argentina, in this May 18, 2014 file photograph. Scientists on July 28, 2015 unveiled a comprehensive analysis of the teeth of the group of carnivorous dinosaurs called theropods, which include the Tyrannosaurus Rex, detailing a unique serrated structure that let them chomp efficiently through the flesh and bones of large prey. (Photo by Maxi Jonas/Reuters)

These images show off some of the world's most majestic creatures silhouetted against the beautiful rising and setting sun. The vibrant pictures feature a variety of animals in the wild and were taken by a host of photographers at locations around the world. The striking images all have one thing in common: the photographers' awe-inspiring ability to perfectly capture the silhouettes of earth's beautiful creatures. Here: a blue wildebeest moves through grassland at dawn with the sun in the background in Mara Naboisho Conservancy, Kenya, Africa. (Photo by Renato Granieri/Caters News/Ardea)

Kevin Jay and Nigel Cox perform some light painting on the beach at Frinton-on-Sea in Essex, UK using colour changing LED light wands during a 25-second exposure on March 4, 2024. (Photo by Kevin Jay/Picture Exclusive)

Colourful pictures all round as people pose on April 7, 2025 in the bright rows of tulips at the family-run Norfolk Tulips near King’s Lynn, UK made famous due to being used to recreate the Emerald City in the Wicked film. (Photo by Bav Media)

A rare fog bow over Needles Headland on the Isle of Wight in UK late Wednesday afternoon, March 26, 2025. (Photo by Paul Jacobs/Picture Exclusive)

Visitors ride a swing attraction during the Hochheim Market in Hochheim, Germany on November 11, 2025. The traditional autumn fair has been held for more than 500 years. (Photo by Matias Basualdo/ZUMA Press Wire/Rex Features/Shutterstock)

Snails are displayed to be sold on the side of a highway, in Sousse, Tunisia, March 27, 2025. (Photo by Ons Abid/AP Photo)