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)

Decaying fishing trawlers known collectively as The Fleetwood Wrecks, are seen at low tide on the banks of the River Wyre in Fleetwood, Britain on September 26, 2023. (Photo by Lee Smith/Reuters)

Autumn colors border a road leading through a small valley near Blankenburg am Harz, Germany, Wednesday, November 1, 2023. (Photo by Matthias Schrader/AP Photo)

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)

Laborers lay down upon a field to cut off the tulips that remained uncut by the tractor in Den Helder, Netherlands April 22, 2017. (Photo by Cris Toala Olivares/Reuters)

Indonesian women sit on a hill as the Suralaya coal power plant looms in the background in Cilegon, Indonesia, on January 8, 2023. A plan for how Indonesia will spend $20 billion to transition to cleaner energy was submitted Wednesday, Aug. 16, to the government and its financing partners, the planners said. (Photo by Dita Alangkara/AP Photo)

People ride a boat on the Tianquan Lake during a foggy day in Xuyi in China's eastern Jiangsu province on November 20, 2019. (Photo by AFP Photo/China Stringer Network)

Firefighters watch as an air tanker drops retardant while battling the Ferguson fire in the Stanislaus National Forest, near Yosemite National Park, California on July 21, 2018. A fire that claimed the life of one firefighter and injured two others near California's Yosemite national park has almost doubled in size in three days, authorities said Friday. (Photo by Noah Berger/AFP Photo)