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)

The damaged battleship USS California, listing to port after being hit by Japanese aerial torpedoes and bombs, is seen off Ford Island during the attack on Pearl Harbor, Hawaii, U.S. December 7, 1941. The 75th anniversary of the attack, which brought the United States into World War Two, is marked on December 7, 2016. (Photo by Reuters/U.S. Navy/National Archives)

German troops in Stalingrad, USSR. September 10, 1942. (Photo by TASS)

British underwater photographer of the year 2021, British waters wide angle category winner and My Backyard category winner. While You Sleep by Mark Kirkland (United Kingdom), common frog taken in Malls Mire, Glasgow, Scotland. (Photo by Mark Kirkland/Underwater Photographer of the Year 2021)

Dogs and humans dressed in all manner of costume participate in the 32nd Annual Tompkins Square Halloween Dog Parade inside Tompkins Square Park on October 22, 2022 in New York City. (Photo by Andrew Schwartz/Splash News and Pictures)

US actress Tiffany Haddish attends a photocall for the film “The Card Counter” presented in competition during the 78th Venice Film Festival, on September 2, 2021 at Venice Lido. (Photo by Yara Nardi/Reuters)

This September 22, 2014 photo, shows a building with street art murals in the Santurce neighborhood in San Juan, Puerto Rico. (Photo by Ricardo Arduengo/AP Photo)

A knight parades in the street during the traditional carnival parade in Cologne, western Germany, Monday, February 16, 2015. (Photo by Martin Meissner/AP Photo)