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)

People explore the ice covered pier in Port Stanley, Ontario, Canada, on December 27, 2022. The ice formations were created by a large winter storm which hit the region on over the Christmas weekend. Temperatures were expected to moderate across the eastern and midwest US on December 27, after days of freezing weather from "the blizzard of the century" left at least 49 dead and caused Christmas travel chaos. (Photo by Geoff Robins/AFP Photo)

A person watches Mount Etna, Europe's most active volcano, light up the night sky with eruptions, as seen from Piazzale Funivia dell'Etna, Italy on December 1, 2023. (Photo by Etna Walk/Giuseppe Distefano/Handout via Reuters)

Participants at the Dubai Run at Sheikh Zayed Road in Dubai, United Arab Emirates on November 26, 2021. (Photo by Ruel Pableo for The National)

A couple take photographs alongside the National Monument on Calton Hill, Edinburgh on Wednesday January 5, 2022, ahead of First Minister Nicola Sturgeon's update to the Scottish Parliament on the Covid-19 situation as the Omicron variant sweeps across the country. (Photo by Jane Barlow/PA Images via Getty Images)

A protester wearing high heels during a demonstration to support International Day for the Elimination of Violence Against Women in Santiago, Chile, November 25, 2016. (Photo by Pablo Sanhueza/Reuters)

Mother and daughter volunteers Niki, right, and Rachel practice their pancake tossing technique in the streets of Wimborne model town and gardens before taking part in the Wimborne Minster virtual pancake race, in Wimborne, England, Tuesday February 16, 2021. Although a physical race cannot take place this year due to the coronavirus restrictions, Wimborne Minster has invited people to film themselves tossing a pancake for 30 seconds and posting it to Facebook. (Photo by Andrew Matthews/PA Wire via AP Photo)

Lucinda Grange perches on the eagle's head on the corner of New York's iconic Chrysler Building in Manhattan, New York City. (Photo by Lucinda Grange/Barcroft Media USA)