A balloon dips into Bald Eagle lake during the 36th Annual Hot Air Balloon Rodeo in Steamboat Springs, Colorado on July 9, 2017. (Photo by Jason Connolly/AFP 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)

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 couple walks across the Francis Scott Key Bridge as the setting sun lights up the clouds in Washington, Friday, October 30, 2020. (Photo by J. David Ake/AP Photo)

Truffle hunter Carlo Marenda pets his dog Buc as they search for white truffles through the Langhe Countryside in Roddi, near Alba, north-western Italy, on November 8, 2020. Despite new measures to stop the spread of the Covid-19, truffles hunters are allowed to search in the countryside in Italy. (Photo by Marco Bertorello/AFP Photo)

Mr Lordi aka Tomi Petteri Putaansuu of the Finnish hard rock band Lordi gets the second jab of his Covid-19 vaccination from nurse Paula Ylitalo (R) in Rovaniemi, Finland, on August 1, 2021, amid the novel coronavirus / COVID-19 pandemic. (Photo by Jouni Porsanger/Lehtikuva/AFP Photo)

People watch the light installation “Onion Skin” by artist Oliver Ratsi performed during the Vilnius 700th anniversary celebration, in Vilnius, Lithuania, 25 January 2023. (Photo by Valda And Kalniņa/EPA/EFE)

Family Donation by Si Thu Ye Myint (Myanmar, Winner). Myin Twin village in upper Myanmar. (Photo by Si Thu Ye Myint/Sony World Photography)