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 180 degrees rotated photograph shows the shadows of Polina (L), a six-year-old Belarusian first grade school girl, and her father, cast on the street while on their way to Polina's first day of school, which marks the traditional start of the academic year, in Minsk, Belarus, 02 September 2019. The start of a new academic year in Belarus, officially called Day of Knowledge, is a festive day for all school and university students in the country. (Photo by Tatyana Zenkovich/EPA/EFE)

People run as Haiti's Senator Jean Marie Ralph Fethiere (PHTK) fires a gun in the air, injuring Chery Dieu-Nalio, a photographer for Associated Press, while facing opposition supporters in the parking lot of the Haitian Parliament and Senate, as the government attempted to confirm the appointment of nominated Prime Minister Fritz William Michel, in Port-au-Prince, Haiti on September 23, 2019. (Photo by Andres Martinez Casares/Reuters)

An innovative photographer attached a camera to a remote-controlled car, allowing him to capture angles of wild lions, rhinos and other animals. Over the last 11 years, Chris Bray has been taking pictures of animals using his toy car contraption while he takes guests on photography tours in Kenya. (Photo by Chris Bray/Caters News Agency)

A heavily tattooed Japanese woman poses for photographs near Asakusa Temple during the third and final day of Sanja Festival, on May 20, 2018 in Tokyo, Japan. Sanja Festival is one of Japan's major festivals and is held annually in the Asakusa area of Tokyo. (Photo by Carl Court/Getty Images)

Behaviour winner; Courting Royals: two royal terns in courtship display by Kristian Bell. Another beautiful morning on a beautiful beach on the Gulf Coast of Florida seemed to prompt these two royal terns to commence an intricate courtship dance. The photograph was taken with a Canon 300mm lens and 2x extender. (Photo by Kristian Bell/Deakin University/Royal Society Publishing Photography Competition 2018)

Visitors look at photographs in the exhibition “Lisette Model Street Life e Horst P. Horst Syle and Glamour” at the art gallery “Camera – Centro Italiano per la fotografia” in Turin, Italy, 27 April 2021. Culture venues reopened to the public as several Italian region are back to COVID-19 yellow zone in the country's tier system. (Photo by Alessandro di Marco/EPA/EFE)

A monolith placed in the Utah wilderness in November 2020. New clues have surfaced in the disappearance of the gleaming monolith that seemed to melt away as mysteriously as it appeared in the red-rock desert. A Colorado photographer told a TV station in Salt Lake City that he saw four men push over the hollow, stainless steel structure last Friday night. (Photo by Terrance Siemon/AP Photo)