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 watch as an acrobat rides his motorcycle around a circular track at an entertainment park set up outside a shrine in Rawalpindi, Pakistan, on June 19, 2013. (Photo by Muhammed Muheisen/Associated Press)

A topless woman walks through Bryant Park following the protest march called the GoTopless Day Parade Sunday, August 23, 2015, in New York. The parade took to the streets to counter critics who are complaining about topless tip-seekers in Times Square. Appearing bare-breasted is legal in New York. But Mayor Bill de Blasio and police Commissioner Bill Bratton say the body-painted women in the square who take photos with tourists are a nuisance. (Photo by Kevin Hagen/AP Photo)

A PETA (People for the Ethical Treatment of Animals) activist with her body painted promotes veganism in Bangkok April 21, 2016. (Photo by Jorge Silva/Reuters)

A woman takes pictures as she stands on the top of a Greek Orthodox Church while the sun sets in the Aegean Sea, in Santorini, Greece's Cyclades island, on Wednesday, June 15, 2022. (Photo by Petros Giannakouris/AP Photo)

American model Emily Ratajkowski, 30, appeared in perfect shape from the front and back in a teeny hot pink bikini and high heels in Los Angeles on September 4, 2021. The beauty was in LA for a fashion show organised by singer Rihanna. (Photo by Backgrid USA)

Students in Aone’s elementary school during break in between the class on April 9, 2015. The school has only six students, two of whom are from the same family. Similarly small schools can be found throughout Japan. (Photo by Ko Sasaki/The Washington Post)

The annual Santacon pub crawl tradition where all the participants have to dress in a Christmas themed costume returns to New York City for its 25th year on December 9, 2023. (Photo by Edna Leshowitz/ZUMA Press Wire/Rex Features/Shutterstock)