Tropical acrobatics by Adrià López Baucells in Manaus, Brazil. An unidentified South American marsupial, although the characteristic black markings on its face indicate it may be a mouse opossum. These small creatures are nocturnal and feed on bugs, fruit and bird eggs. (Photo by Adrià López Baucells/2019 Royal Society of Biology Photography Competition)

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)

Sculptures entitled “The Rising Tide” by British sculptor Jason deCaires Taylor are seen beside the River Thames in front of the Houses of Parliament and the London Eye ferris wheel in London, September 3, 2015. The representations of four horses and riders are fully visible at low tide but become immersed underwater twice a day as the Thames rises to reach full tide. The installation will be on display throughout September as part of the annual Totally Thames festival. (Photo by Toby Melville/Reuters)

“Hard for Life”. (Photo by Theo Vu Xuan/Sony World Photography Awards/WENN.com)

A Funnel Web spider is pictured at the Australian Reptile Park January 23, 2006 in Sydney, Australia. The Funnel Web is one of Australia's deadliest animals, with a venom that is packed with at least 40 different toxic proteins. A bite from a Funnel Web causes massive electrical over-load in the body's nervous system. Finally, fatalities occur from either heart attack or a pulmonary oedema, where the capillaries around the lungs begin to leak fluid and the patient effectively drowns. Death can come as quickly as two hours after a bite if no medical treatment is sought. Due to advances in anti-venom, there has been no death from a Funnel Web bite in Australia since 1980. Australia is home to some of the most deadly and poisonous animals on earth. (Photo by Ian Waldie/Getty Images)

A female hippopotamus named “Mali”, which means Jasmine, eats fruits arranged to look like a cake during her 50th birthday celebration at Dusit Zoo in Bangkok, Thailand September 23, 2016. (Photo by Chaiwat Subprasom/Reuters)

Skywhale and Skywhalepapa, created by artist Patricia Piccinini before flying over Melbourne on March 19, 2022 in Melbourne, Australia. It is the first time Piccinini's work Skywhales: Every Heart Sings has flown over Melbourne, as part of MPavilion. (Photo by Asanka Ratnayake/Getty Images)

A hyena kisses his own reflection while appearing to walk on water. (Photo by Jake De Wet/Caters News Agency)