Jason Ramsay and Amy Laverty, from Arbroth, Scotland, pose beside a large Christmas tree at Bondi Beach on December 25, 2016 in Sydney, Australia. Bondi Beach is a popular tourist destination on Christmas Day. (Photo by Don Arnold/Getty Images)

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 farmer tends to his field as Mount Sinabung releases pyroclastic flows in Tiga Pancur, North Sumatra, Indonesia, Saturday, June 13, 2015. The volcano, which was put on it highest alert level last week, has sporadically erupted since 2010 after being dormant for 400 years. (AP Photo/Binsar Bakkara)

Security forces' members gesture towards a woman in Santiago, Chile on December 18, 2019. (Photo by Andres Martinez Casares/Reuters)

Australian ballet dancer Marilyn Rowe prepares to perform Swan Lake with the Australian Ballet at the Canberra Theatre in 1978. Rowe was appointed director of the Australian Ballet School in 1999. (Photo by John Crowther/The Guardian)

People gather to view a new art installaiton at Waterfront Park entitled, Interstellar Influencer (Make an Impact) by Jason Klimoski and Lesley Chang of STUDIOKCA on Saturday March 30, 2024 in Alexandria, VA. The artwork depicts an asteroid that struck the region millions of years ago. (Photo by Matt McClain/The Washington Post)

A rainbow cuts through a squall above The Needles, the Isle of Wight, on Tuesday evening, April 16, 2024. (Photo by Jamie Russell/IslandVisions via BNPS)

The sun appears in a light bulb in Yantai, Shandong province, China, on June 17, 2024. (Photo by Costfoto/NurPhoto/Rex Features/Shutterstock)