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)

Behaviour winner; Courting Royals: two royal terns in courtship display by Kristian Bell. Another beautiful morning on a beautiful beach on the Gulf Coast of Florida seemed to prompt these two royal terns to commence an intricate courtship dance. The photograph was taken with a Canon 300mm lens and 2x extender. (Photo by Kristian Bell/Deakin University/Royal Society Publishing Photography Competition 2018)

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

David Goffin of Belgium meets a koala during a promotional event for the Australian Open tennis tournament at Melbourne Park on January 17, 2018. (Photo by Fiona Hamilton/Reuters/Tennis Australia)

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)

The Prince Albert Cairn, built in 1862 by Queen Victoria, is surrounded by snow and ice, near Balmoral, Aberdeenshire, Scotland, Friday November 22, 2024. (Photo by Jane Barlow/PA Wire via AP Photo)

The sun rises through the thick fog that covers the city of Frankfurt, Germany, Friday, November 12, 2021. (Photo by Michael Probst/AP Photo)

Scott Meiklejohn gets into character as a mummy during a photo call on October 10, 2019 in Stirling, Scotland ahead of “Hallowild”, Blair Drummond Safari Parks annual Halloween event. This years theme in the haunted walkway is an egyptian tomb with special 3D effects alongside actors playing the roles of Pharaohs and Mummies. (Photo by Andrew Milligan/PA Images via Getty Images)