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)

Switzerland's Lea Sprunger in action during the 300m hurdles race during the Weltklasse Zurich Inspiration Games, a virtual international athletics meeting with 30 athletes in eight disciplines at seven venues worldwide, in the Letzigrund stadium in Zurich, Switzerland, Thursday, July 9, 2020. (Photo by Arnd Wiegmann/Reuters)

“Catch of the Decade”. Can you guess what happened next? Photo location: Katmai National Park, Alaska, USA. (Photo and caption by Aaron Baggenstos/National Geographic Photo Contest)

Savita, a street performer, helps her dog to balance on empty tin containers as they perform at a roadside in Ahmedabad September 7, 2014. (Photo by Amit Dave/Reuters)

The extremely rare Kelvin-Helmholtz cloud formation lurking in the skies over Northumberland in North East England on December 5, 2023. The distinctive formation gets its name from scientists Lord Kelvin and Hermann von Helmholtz who studied the physics behind the rare cloud. (Photo by Ian Davison/South West News Service)

Mount Sinabung looks calm as seen from Karo, North Sumatra at dawn on August 8, 2021. (Photo by Tibta Nangin/AFP Photo)

The towers of the Notre-Dame de Paris Cathedral, which was ravaged by a fire in 2019, are reflected in a puddle ahead of the reopening ceremonies, in Paris, France, on December 4, 2024. (Photo by Stephanie Lecocq/Reuters)

People take part in the Burning of the Clavie fire festival in Burghead, Moray, UK on Saturday, January 11, 2025. Burghead welcomes in the New Year twice each year, on both January 11th and the more traditional January 1st. (Photo by Jane Barlow/PA Images via Getty Images)