A sun bear reacts to triple-digit temperatures at the Henry Doorly Zoo in Omaha, Nebraska, where the temperature reached 103 degrees Fahrenheit on July 6, 2012. (Photo by Nati Harnik/Associated Press)

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

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)

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)

These little grizzly bear cubs had fun making a real splash when their mum took them for a dip to learn how to fish. Kamchatka, Russia. (Photo by Marco Mattiussi/Solent News & Photo Agency)

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)