A reflection on waste liquid shows a tourist walking near the Blue mosque at the Sultanahmet Square on the first day of the Muslim fasting month of Ramadan in Istanbul on April 13, 2021. (Photo by Ozan Kose/AFP Photo)

Clouds cover the sky over the Ernst-Taehlmann-Park housing estate after a thunderstorm in Berlin, Germany, Thursday, March 11, 2021. (Photo by Markus Schreiber/AP Photo)

A fishing boat (L) heads out to sea at dawn in Lhokseumawe, Aceh on August 9, 2021. (Photo by Azwar Ipank/AFP Photo)

People are silhouetted while riding the Atmosfear double swing, which lifts riders more than 66 meters into the air while spinning at up to 70 km/h, at the Pacific National Exhibition at sunset in Vancouver, British Columbia, on Tuesday, August 31, 2021. (Photo by Darryl Dyck/The Canadian Press via AP Photo)

A view of trees shrouded in fog on a late summer morning between Tureby and Slimminge on Zealand, Denmark, 10 September 2021. (Photo by Mads Claus Rasmussen/EPA/EFE)

The sun rises through the thick fog that covers the city of Frankfurt, Germany, Friday, November 12, 2021. (Photo by Michael Probst/AP Photo)

In this Monday, January 23, 2017 photo, chicken feet snacks shop owner Leung Kin-kung testes a chicken feet in Hong Kong. Saturday marks the start of the lunar Year of the Rooster and families in China will reunite for festivities, fireworks and food. While tradition calls for feasting on “auspicious” foods, many will also munch on staple snacks like “phoenix claws”, the Chinese name for chicken feet. (Photo by Vincent Yu/AP Photo)

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)