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)

A polar bear fast asleep at London Zoo. (Photo by Fox Photos/Getty Images). 1961

A visitor holds up her toy bunny to the aquarium glass in front of Aurora the Russian polar bear at the Sao Paulo Aquarium in Sao Paulo, Brazil, Thursday, April 16, 2015. (Photo by Andre Penner/AP Photo)

CANADA: Stanley Ferdinand filets large trout he caught in Great Bear Lake in Deline, Northwest Territories, Canada September 8, 2016. (Photo by Pat Kane/Reuters)

Members of the Coney Island Polar Bear Club warm up before swimming at the beach at Coney Island in New York, December 15, 2013. (Photo by Eric Thayer/Reuters)

TCU Horned Frogs twirler performs at halftime of the game against the Baylor Bears at Amon G. Carter Stadium in Fort Worth, Texas, USA on November 6, 2021. (Photo by Kevin Jairaj/USA TODAY Sports)

A grizzly bear waves its paw at a vehicle on the road to Nemrut Crater Lake in Tatvan district of Bitlis, Turkiye on August 24, 2023. (Photo by Muhammed Selim Korkutata/Anadolu Agency via Getty Images)

A view of fluffy toy bears displayed for attraction outside the windows of a hotel in Yantai in Shandong province Thursday, January 6, 2022. (Photo by Tang Ke/Future Publishing via Getty Images)